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Pests On Plum Trees – How To Deal With Common Plum Tree Pests

Of the fruiting trees, plum trees have the least number of pests. Even so, plum trees do have some insect problems that can wreak havoc with fruit production or even kill the tree. Early identification of pests on plum trees and controlling pests on plums can make all the difference in the health of the tree and its yield. The following information focuses on common plum tree pests.

Help, I Have Plum Tree Bugs!

First of all, don’t panic. Early identification of plum tree bugs will help you to figure out how to control or eradicate them. Inspect the tree often for any signs of infestation. Here are the most common plum tree insect problems to watch out for:

Plum Curculio

One of the most common plum tree pests is plum curculio. This ½-inch long beetle overwinters in the soil and then emerges in the spring. Adults are brown and scaly with long pinchers that they use to tunnel into fruit. The female beetles lay eggs under the surface of developing fruit. The emerging larvae burrow deep into the fruit as they eat, causing it to rot.

Start checking for signs of plum curculio just as the tree begins to form fruit. Check the fruit for any signs of egg-laying scarring. If you see any such signs, spread plastic sheeting under the tree in the early morning. Shake the branches to dislodge adult beetles. They will fall onto the plastic tarp, looking much like bud scales or other debris. Gather all the beetles and dispose of them. This procedure must be repeated daily in the spring when they are most active and then off and on through the summer.

If this sounds like too much work, of course, spraying with a low-toxicity insecticide is another option. As soon as you see any sign of egg-laying scars, apply the first round of insecticide and then spray again two weeks later.

Japanese Beetles

Japanese beetles are another common pest found on plum trees. These beetles are small and reddish-brown with black heads. First transported to the United States in 1916, Japanese beetles are equal opportunity marauders, infesting not only plum trees but many other plants. Both grubs and adults feast on foliage from July through September.

Plum Aphids

Plum aphids are another common pest found on plum trees. Aptly names, as plum leaves are the pests’ favorite food. These aphids are green, yellow or brown and under ½ inch in length. They are found in curled foliage. The curled leaves then do not photosynthesize properly, which stunts the tree and/or fruit and, in severe cases, will kill the tree.

Rust Mites

Yet another common pest found on plum trees are rust mites, which also affect other fruits trees like pears. Less than ¼ inch in length, they may be yellow, red, pink, white or even purple. In the case of mite infection, leaves turn a silver color and curl up. If you see this, look on the underside of the leaves for clusters of mites to verify the tree has rust mites.

Controlling Pests on Plums

We already discussed controlling plum curculio; apply a pesticide in the fall but what can be done about controlling other pests on plums? Shake the limbs of the tree to dislodge Japanese beetles much as recommended for non-chemical control of plum curculio. Kill the beetles by plopping them into some soapy water.

Aphids can be controlled by spraying the tree with Neem oil at the first sign of infestation. Rust mites can be controlled by spraying with a sulfur spray in the early spring.

Cooperative Extension: Tree Fruits

Insect Pests

Insects can devastate a crop of fruit in an unsprayed orchard. Unfortunately, there are no varieties with resistance to insects, but pears and peaches generally bear fruit with less damage in unsprayed orchards. Where a greater degree of protection from insect pests is desired, a combination of a few well-timed insecticide applications is an option. Always follow the label instructions for mixing rates and for safety precautions.

An apple fruitlet with plum curculio egg-laying scar.

Plum curculio is a major insect pest of apple, plum, apricot and cherry, and a minor pest of pear and peach. Plum curculios overwinter under leaf litter at the edges of woodlots. They emerge in May and slowly move into orchards where they mate. After bloom until mid-July, adult female curculios lay eggs in fruit causing a characteristic crescent-shaped scar. Adult plum curculios will also feed on young fruit causing a tiny hollowed out cavity. The eggs hatch into larvae and feed inside the fruit and seed cavity, causing infested fruit to drop in early summer. Plum curculio larvae move from fallen fruit into soil, where they pupate and emerge as adults from late July into September. These next generation adult curculios feed on apples before finding overwintering sites. Late summer fruit feeding damage appears as irregular shaped holes that do not have time to heal before harvest. Feeding holes are often on the bottom end of the apple.

To prevent damage by plum curculios, an insecticide spray should be made shortly after petals fall from the blossoms or at the first sign of damage. For a high degree of control, a second application can be made about ten days later. If cool weather occurs, a third application provides a high level of control.

To protect bees, always wait until bloom is completely over to apply any insecticide. Products containing carbaryl (Sevin™) or phosmet (Imidan) are effective against plum curculio. Organic products such as pyrethrin are quickly degraded and will require reapplication at three- to seven-day intervals for effective control. Azadirachtin and other neem products have little or no effectiveness for controlling plum curculio.

Surround™ is a clay-based repellent that is also certified for organic use. In order to be effective, Surround™ coverage on fruit should be thorough beginning shortly after petals fall and re-applied weekly to maintain a white coating on the fruit and foliage until early July. Surround™ protection is designed to repel plum curculio until the egg-laying period is over.

The European apple sawfly creates scarring along the fruit surface and holes in the side of the fruit.

European apple sawfly is less prevalent that plum curculio in most years, but their seasons for damaging fruit overlaps. The adults lay eggs on the base of the apple flowers during bloom. The eggs hatch into larvae that initially feed on the surface of the fruit. This initial feeding creates a winding scar on the surface of the apple. A high degree of control requires an insecticide application soon after the petals fall from the tree. Delay of two or three days provides less control of damage, but later sprays will help prevent movement of larvae into a second or third fruit. Starting at about two weeks after petals fall, larvae that were not killed with a petal fall spray will begin moving from the first infested apple to a nearby apple. The sawfly creates tunnels into these apples, leaving a hole in the side. These fruit will soon drop off the tree. Insecticides and repellents that are applied for plum curculio also prevent damage by sawfly.

An apple that was attacked by the
codling moth.

Codling moth can cause considerable damage in unsprayed orchards and is a primary pest of apple, and to a lesser degree of pear. The larvae damage fruit when they tunnel into apples and pears and feed on the seeds. An entry hole with sawdust-like excrement (“frass”) may be visible at the blossom end or on the side of the fruit. The damage to the fruit resembles the damage caused by European apple sawfly, but occurs later in July and into the fall.

Codling moths overwinter in the orchard as larvae. Following pupation, they emerge as adults in May and June when they mate and lay eggs in summer. Their offspring pupate in July and emerge as adult moths in August.

Where insecticide sprays with carbaryl or phosmet have been used to prevent plum curculio damage, there is much less chance of severe problems with codling moth. If pyrethrin or Surround™ were the only materials used against plum curculio, then additional treatments targeted against codling moth will be beneficial. Organic options include Surround™ coverage maintained through mid July; or two to three applications at seven- to ten-day intervals of Bt (Bacillus thuringiensis), azadirachtin, or Entrust™ from mid June into July.

The apple maggot larva creates brown
tunnels in the flesh of the apple.

The apple maggot larvae feed on the flesh of the fruit leaving a brown trail inside the apple in late summer. They overwinter as pupae in the soil and emerge in late June and July. Approximately ten days after emergence, the females begin to lay eggs in apples. They favor apples and plums.

Eggs and larvae are protected from insecticides and repellents since they are inside the apple. When insecticides are used to prevent damage, they should be applied just before egg laying occurs. Insecticide applications, starting in mid-July, with a renewal application in late July or early August, and a final application in mid August, are usually adequate to prevent apple maggot infestation. The final application may be omitted for earliest ripening varieties, and the first application maybe omitted for the latest ripening varieties. Insecticides should not be applied right before harvest. Esfenvalerate cannot be used within 21 days of harvest. Carbaryl (Sevin™), tree fruit spray and phosmet (Imidan) cannot be applied in the week before harvest.

Red colored spheres, coated with the sticky substance, Tangletrap™, can be used to trap apple maggot adult flies.

Red spheres the size of a large apple and covered with the sticky substance, Tangletrap™, can be used to trap adult flies. At least one trap for every 100 apples is needed to adequately prevent infestation. Use one trap on a dwarf tree or four traps on a semidwarf tree. Place traps in the orchard the first week of July. Traps should be completely covered with Tangletrap™ and hung from a branch in the outer part of the tree, surrounded by fruit, but not hidden by leaves.

The repellent Surround™ can be used in conjunction with traps or on its own for apple maggot. However, Surround applied to fruit in August may still be on the fruit at harvest and should be washed off before consuming the apple.

Different aphid species commonly occur on fruit trees, but are usually insignificant or only aesthetically damaging. Aphid populations are usually reduced by their natural enemies later in the growing season, so insecticide sprays are not warranted. One exception to this is for very young trees where a heavy aphid population can stunt growth. There are many fruit tree spray products to control aphids if needed. However, on established trees, spray application is typically not needed.

Spots on pear leaves from pear leaf
blister mites.

Pearleaf blister mites feed on leaves and cause red spots in springtime, usually along the midvein. A few weeks later, mites enter the blisters and lay eggs. These spots eventually turn brown or black in summer. Feeding on young fruitlets will cause depressed areas with russetting on the fruit surface. Blister mites overwinter beneath bud scales, becoming active at budbreak and causing leaf damage in the early stages of spring growth. The damage they cause is minor in most cases and not likely to affect the tree. Where damage is severe, a dormant oil spray can be applied according to the label instructions just after the buds swell in the delayed dormant period and horticultural oil after leaf growth begins. Blister mites are not likely to cause leaf damage in summer.

Pear slug is an uncommon and sporadic pest of pear trees. They eat the upper surface of pear leaves, but avoid the veins. Damaged foliage has a lacy or skeletonized appearance. They do most of their feeding in summer and are usually gone from the tree by the time the damage is spotted. In some cases, they cause substantial loss of foliage. Where damage is mild, it is of no consequence to the tree.

Japanese beetles feed on the foliage of fruit trees and prefer plum and cherry leaves to other types of fruit trees. The level of damage is most often insignificant, so the use of insecticides is not of value.

Earwigs feed on peach, nectarine and apricot fruit as they ripen in summer. Earwigs also feed on nectarines soon after bloom causing a large scar on the surface of the fruit at harvest. They have an elongated, dark brown or reddish brown body with pincers at the end.

As fruit ripen, they move from the ground cover into trees. Removing shoots that are in contact with ground cover will inhibit their movement into trees.

Monitor their presence in the orchard by placing a rolled up newspaper in the orchard several weeks before fruit begin to ripen. This should be examined for earwigs once a week. As they begin to move into the tree, carbaryl insecticide can be applied to the trunk. The efficacy of organic insecticides for control of earwigs has not been tested.

Trunk borers are insect larvae that feed on the bark and wood inside the trunk. Trees less than ten-years-old, and trees with a trunk diameter less than four inches are particularly vulnerable. Many young and dwarf fruit trees in home plantings are killed by borers. White spiral plastic trunk guards and other close fitting tree wraps encourage trunk borer egg laying because they provide protection for young larvae. Once borer larvae are feeding inside the trunk, they are protected from natural predators and insecticide sprays. Preventing borer infestation and killing borer larvae before they tunnel deep into the trunk are key to protection.

Peach tree borer can be a serious pest for younger trees. The larval stage feeds on the internal trunk tissues eventually killing the tree. To prevent trunk borer infestation, a trunk application of insecticide can be made in July and another in August. Select an insecticide which indicates on its label that it is appropriate for fruit trees and apply it according to its label instructions for effectiveness and safety. Keeping grass and weeds short around the trunk will also lessen the chance for borer egg laying.

Roundheaded apple tree borers lay their eggs on the lower trunk usually near the ground, from late June into August. Upon hatching, the larvae burrow into the lower trunk. The tunneling can kill the tree by structural damage to water conducting tissues and in severe cases will cause the trunk to break off completely. Small pinholes with reddish frass indicate the presence of boring larvae. Pencil-sized holes in the trunk indicate that the borer has done extensive damage and has already left the trunk. Flatheaded apple tree borers feed primarily on the sapwood of trunks and larger branches on trees with poor growth, and trees with damaged bark. The dogwood borer, which feeds near the surface of the trunk, is less devastating.

Fruit trees sprayed with foliar insecticides during June, July and August are much less likely to be attacked by trunk borers. For trees not receiving foliar insecticide sprays, insecticide application to the trunk at two-week intervals from late June to mid-August will reduce the likelihood of borer attack.

To prevent borers from laying eggs, a loose-fitting barrier such as mosquito netting or window screen can be wrapped around the lower trunk and closed at the top by tying it with a cord and closed at the bottom by mounding soil over it. Barriers should be in place by the end of June, but loosened or removed after harvest to prevent girdling. When a cord or trunk guard girdles a tree, it kills the tree and defeats the purpose of the trunk guard.

White interior latex paint, diluted with water at a ratio of one part paint to one part water, can be painted on the lower two feet of the trunk to repel borers. Other types of paint may harm trees.

Careful inspection of the lower trunks in September and May can reveal sunken wood and loose bark where borers have invaded. Borer larvae feeding near the surface can be removed with a sharp cutting tool. A stiff wire is useful to kill borers that have tunneled further into the trunk.

Insecticides Available in Organic Formulations

Read and follow all safety instructions before using any insect control product. Use only products that specify the type of fruit you wish to spray, or “tree fruit” on the label. “Organic” in this context refers to products allowed by organic certification programs.

Azadirachtin, an extract of neem oil, and neem oil act as repellents with mild insecticidal activity. Azadirachtin and neem oil have limited effectiveness for control of most fruit tree pests. Toxicity to bees is moderate. Many product are available.

Bt is produced by the bacteria Bacillus thuringiensis and is effective for control of moth and butterfly caterpillars, such as codling moth and leafroller. Bt has relatively short effectiveness because it is quickly degraded by sunlight. Protection lasts no longer than one week. Thus multiple applications are needed for adequate control when relying solely on Bt. It is not hazardous to bees. It is sold as a number of different products.

Dormant oil can effectively control spider mites, pear psylla, pear leaf blister mites and scale insects, but not other insect problems. Commercial formulations contain an emulsifier that enables oil to be mixed with water. While spraying dormant oil, agitate the oil-water mixture to keep them from separating. Do not mix oil with captan or sulfur fungicides, as these combinations burn leaf and fruit tissue. Do not apply dormant oil after foliage emerges in spring. It is not hazardous to bees.

Spinosad is an insecticide that controls codling moth leafrollers, and apple maggot. It has a low degree of bee toxicity. Many product are available.

Pyrethrin is a botanical insecticide effective against many insect pests, but degrades quickly. Frequent applications are needed for reasonable effectiveness. It is highly toxic to bees.

Surround™, a clay product, acts as a repellent thereby preventing insects from damaging fruit. For maximum effectiveness, Surround should be applied weekly to achieve full coverage of the fruit. It is not hazardous to bees.

Other Insecticides

Permethrin, resmethrin, and esfenvalerate are synthetic pyrethroid insecticides effective against a broad range of tree fruit pests. They are sold under many product names. Highly toxic to bees.

Carbaryl (Sevin™) controls most pests and can be used as a fruit thinner of apple. Apply it one to three weeks after bloom for fruit thinning. This will reduce the number of fruit on the tree and will increase flowering the following season. When applied just before hot weather (>85°F), it can over thin. Highly toxic to bees.

Fruit tree spray mixes typically contain a mixture of carbaryl or pyrethrum insecticide and the fungicide, captan. It is meant to be used for both insect and disease control. Highly toxic to bees.

Phosmet (Imidan) is very effective for control of most pests of apple. It is useful when a high degree of insect control is desired. Highly toxic to bees.

Where company or brand names are used, it is for the reader’s information. No endorsement is implied nor is any discrimination intended. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Stone Fruit Insects

1) Tarnished Plant Bug


Photo: Russ Ottens, University
of Georgia, Bugwood.org

Adults are up to 1/4-inch in length and have a flattened oval appearance and a mottled brown color. Plant bugs can be a major peach and plum pest and are a difficult pest to detect and control. They are most active from bloom stage to 5 to 10 weeks after bloom. They pierce and feed on blossoms and fruit causing deformities, shallow depressions, and fruit drop. Strings of oozing gum are often visible around feeding sites on fruit.
To protect your crop from this pest, control weeds around trees, especially wild mustard, a preferred host plant. Apply a registered insecticide during the prebloom and petal fall periods when pest is identified as a problem.

Tree Fruits – Pest Control and Spray Schedules

2) Oriental Fruit Moth


Photo: Eric LaGasa, Washington
St Depart of Agriculture, Bugwood.org

Adult


Photo: Clemson University – USDA
Coop. Extension Slide Series, Bugwood.org

OFM larva


Photo: Jonas Janner Hamann,
Universidade Federal de Santa Maria
(UFSM), Bugwood.org

OFM twig damage

Photo: G. Morvan, INRA, Montfavet,
Bugwood.org

OFM damage to peach

Is considered a damaging pest. The larvae kill shoot tips and invade the flesh of the peach. Three or more generations develop in Maryland. This pest prefers peach trees to plum and cherry. Larvae of the early generations burrow down from the shoot tips and stunt extension growth. The larvae of later generations enter the fruit so that, by harvest, the fruit either falls to the ground or is wormy and useless. Larvae sometimes enter through the green fruit stem and no visible sign of internal injury is present. More often, you will notice scattered deposits of gum (thick sap) and frass (larval excrement) on the fruit surface. Prune out and dispose of wilted tips, 6 inches below visible damage.

Tree Fruits – Pest Control and Spray Schedules

3) Peach Tree Borers and Lesser Peach Tree Borers


Signs of damage from clearwing
borers (peach tree borers) include
holes in the bark, reddish frass in
bark crevices or around the bottom
of the tree, gummosis, and branch
dieback

The adult lays eggs on trunk or branches

Peach tree borer larva (bores into
trunk or branches)

Peach tree borer damage to trunk

These are two similar pests that attack different parts of peach trees. Peach tree borer larvae grow into thick-bodied 1-inch-long larvae with brown heads that burrow through the inner bark of peach and nectarine trees at or just below the base of the tree. One borer can kill a small tree; two or more may kill larger trees. The lesser peach tree borer adult lays its eggs on the trunks and limbs of peach and nectarine trees, often in or around wounds and cankers caused by the Leucostoma fungus. The activities of both borers result in the oozing of amber gum by the peach tree, which often contains sawdust-like insect frass (larval excrement). The gum is produced by the tree as a defensive response to the injury. Where lesser peach tree borer wounds are found on small branches, they should be cut out and destroyed.

Adult borers (moths) begin emerging in late May to early June and can be found through September. The female adult is a large, blue and orange, clear-wing moth that mates and lays eggs (mostly at the base of trees) soon after emergence. Larvae feed in tunnels below bark and overwinter in trees, renewing activity in early spring.
Nonchemical management:
•Borers attack stressed trees. Keep peach trees in good health through proper planting, watering, fertilization, pruning, and pest management.
•Monitor for borer holes. In May, scrape away gum and dead bark from lower trunk and large roots. Come back in 1 week and look for new gum and frass deposits. Make vertical cuts with a sharp knife through these entrance holes. Then, insert a stiff thin wire and stab larvae; repeat in 1 week and then mound soil over damaged area (if low on the trunk).
•Wrap a band of corrugated cardboard on the lower trunk below soil level to prevent egg laying or to trap larvae before they tunnel into tree.
•Where holes and frass are observed but no sap is oozing from tree, beneficial entomopathogenic nematodes may be used as a drench applied to the trunk or injected into borer holes.
•Bt can also be injected into borer holes with a syringe.

Tree Fruits – Pest Control and Spray Schedules

4) Plum Curculio


Photo: Clemson University – USDA
Coop. Ext. Slide Series, Bugwood.org

Photo: NHFruitGrowers.org
Crescent shaped scars on fruit

Can be a pest on apples, but the immature larvae do more damage to soft fruits such as cherries, peaches, and plums. An entire crop of unsprayed plums can drop to the ground early because of this pest. Among the insect pests, plum curculio has the potential to destroy an entire plum crop and much of a peach and nectarine crop within a month after fruit set.

Non-chemical management:
• Hang plastic traps (empty 2 liter soda bottles) filled halfway with molasses, vinegar, and water, from tree limbs at petal fall.
• Cover individual fruits after pollination with small paper bags.
• Remove infested fruit from tree.
• Lightly cultivate soil prior to budswell to disrupt/kill overwintering adults.
• Keep trees pruned and open (curculios prefer deep shade).
• Lay a white sheet under trees, tap limbs with padded stick, and capture adults when they drop to the ground.

Tree Fruits – Pest Control and Spray Schedules

5) Cherry Fruit Fly

Cherry fruit fly maggot inside a cherry

A common pest of sweet cherry and tart cherry fruits. Adult flies emerge from pupal cases in May. Adults feed in trees, mate, and then females lay eggs on ripening fruits. The larvae are 1/4-inch long, legless, and white to yellow in color. They feed singly on fruit pulp for up to 2 weeks. They complete their lifecycle when infested fruits fall to the ground. Hang sticky yellow traps in trees and monitor for the appearance of adults. They are two-thirds the size of houseflies and have dark bands on their wings. An insecticide should be sprayed five days after adults appear on traps. Laying a tarp or weed barrier fabric directly on the ground under the canopy in early May will prevent the adults from emerging. Promptly remove all infested fruit from the ground and the tree.

Tree Fruits – Pest Control and Spray Schedules

6) Japanese Beetles

They skeletonize the leaves (feed between the leaf veins) of stone fruit trees, especially sweet and sour cherry and Japanese plum. Sweep Japanese beetles into a bucket of soapy water. Where feeding is severe, use a labeled organic or chemical insecticide. Avoid Japanese beetle traps, because they tend to attract large numbers of beetles which can lead to additional plant damage.

Tree Fruits – Pest Control and Spray Schedules

7) Brown Marmorated Stink Bugs

8) Spotted wing drosophila (SWD), Drosophila suzukii

Tree Fruits – Pest Control and Spray Schedules

9) Fruit flies, yellow jackets, other wasps, and hornets

These insects will hover around ripe fruit. Do not allow fruit to become overly mature on the tree and pick up fruit that drops to the ground. Do not use insecticides.

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Features

Warton’s Bill Blackledge is one of the county’s most popular and sought after gardeners. If it’s green and needs watering, Bill can tell you about it. He has been answering BBC Radio Lancashire listeners’ queries for over thirty years, which means he’s been there nearly as long as the transmitter!

His knowledge is encyclopedic. After training at the under the then Ministry of Agriculture, Bill spent over twenty years at the Department of Biological and Environmental Services at Lancaster University. Now, he’s a regular course tutor at Alston Hall, Longridge and Lancaster Adult College.

For three decades, Bill has travelled the county with fellow judges as a regional judge for North West in Bloom.

So, whatever the problem, we like to think Bill can sort it out… at least that’s the theory!

DAMSONS

Dave Jones asks…

We were given a damson tree last year which we replanted in our garden. The leaves curled over and developed lumps over all the surface of the leaves. Could you please give me some advice on this?

Bill replies…

Your Damson Tree Dave could be suffering from the plum leaf curling aphid which causes the leaves to become tightly curled, crumpled and distorted and on the underside of the leaves you will find pale yellow-green insects. The aphids suck the sap from the leaves and this causes the leaves to become distorted and during the early summer months the winged adults move on to alternative host plants but return to the Damsons during the autumn period to lay overwintering eggs at the base of the branches. There are no insecticides on the market which the amateur garden can use to control the aphids but, during the winter months a tar oil winter wash will reduce the overwintering eggs.

Judith Chisholm asks…

There is a damson tree mostly in shade at the end of the garden. It is also covered with ivy. It is exuding a lot of golden resinous substance all over the trunk. Small snails seem to have been caught in the resin, so it must move quickly. Is the tree ill? It fruited last year.

The golden resinous substance oozing from the trunk of your Damson Tree Judith has probably been caused by the bacterial Canker disease which is a serious disease of Damsons, Cherries and other stone fruit trees and, I am afraid that you are going to have to check the branches which have been infected and these will need to be cut out and removed to stop the spread. The stems on the tree then need to be treated with a tree sealant to stop infection. I feel that it would also be worthwhile to remove the Ivy which is covering the tree.

Nicky asks…

My nan has got a tree in her garden that has been grafted it is a damson that has been grafted on to a plum tree and it is bearing fruit, can you give me some idea of whether it is possible to eat the fruit that looks like damson? Thanks

Your Damson Tree belongs to the same family as Plums and there is no reason why you cannot eat the fruit Nicky. An excellent all-round variety of Damsons is Merryweather and if you have limited space in your garden the Shropshire Damson is an ideal choice.

Elly asks…

I have recently planted a damson tree and just noticed that the leaves are now covered in holes, however no other shubbery or apple trees in the garden have this problem.

The holes in the leaves of your Damson Tree Elly is probably Shot Hole Disease which is a fungal disease that attacks Damsons, Peaches and Cherries. Brown spots appear on the leaves which then turn into small holes and I am afraid that although they do not cause much harm to the tree there is no cure for the problem. The disease tends to attack weak trees and I would suggest you give your Damson Trees during early spring/summer a liberal dressing of a general base fertiliser such as Fish Blood and Bone Meal or Vitax Q4.

Adrian asks…

I have a Damson Tree which is around 12′ to the tallest branch. It has gone very straggly and I would like to prune the tree. What is the best advise you can give please?

I would wait until early Summer before pruning your Damson Tree Adrian – this will cut down on the chances of your tree being infected by the Silver Leaf Fungi disease, the air borne spores are more active during the winter period. Again to avoid infection once you have pruned your tree I would treat the cuts with Aborex Sealant.

Amanda Hutchinson asks…

We have a truly enormous damson tree – probably about 20′ tall and 30′ wide. It is more like an overgrown bush in that it has 2 main “trunks” and lots of main boughs from low down. It’s growing out and out at the sides, reaching for the light from its canopy. It’s now invading our space, and I’m worried the weight will split it eventually. How much can I prune (re major boughs) and when is the best time? It’s the life of our garden and I don’t want to harm it!

The time to prune back your Damson Tree Amanda is during the summer months of July/August as this period will cut down the risk of infection from Silver Leaf Fungi Disease which is more dominant during the winter period. Regarding the size of your Damson Tree it will require major pruning and I feel that it would be worthwhile to get ‘on the spot’ advice from a qualified Tree Surgeon regarding which boughs need removing. But, I would stress that pruning is carried out during the summer period.

Jenny Creed asks…

I have recently been given a Damson tree which I have planted in our garden. However, I am a bit worried it doesn’t appear to have grown and the buds on it are black. Is it too late to do anything? Please could you let me know what I can do as it was a present and I really don’t want it to die.

There is nothing that you can do at the present time Jenny you will have to wait and see if your Damson Tree comes into leaf in the Spring and, if it does come into leaf and with it being a newly planted tree you will need to keep an eye of the watering during the summer months. If however your Damson Tree does not come into leaf and it has died a reputable Garden Centre should replace the tree.

J Bowdler asks…

I have a damson tree about 12 feet tall it has slight leaf curl. I noticed yesterday that most of the fruit seems shrivelled and looks like it is rotting with a white coating. Is it due to the hot weather or is it because we cut it back in the spring and did not coat the branches after cutting? It there anything we can do?

The leaf curl on your Damson Tree could quite easily have been caused by aphids and it would be worth looking on the under side of the leaves to see if there are any present. The white coating on the fruit sounds very much like powdery mildew which, if badly infected, can cause the fruit to shrivel. In some respects the small fruit on your tree could have been quite easily caused by very dry conditions and during the fruiting period – if at all possible – it is well worthwhile to give your trees a good watering. You mention pruning your tree in the Spring – this would not have caused your fruit to shrivel or the powdery mildew to appear but the best time to prune your Damsons is June/July time to avoid infection by Silver Lead Disease.

Rhiannon Ratcliffe asks…

The bark of my damson tree is splitting and flaking. Is this a disease and should I treat it? It is also growing more branches on one side making it look lop-sided. Can I prune it and if so when?

If your Damson Tree has been planted in a badly drained/acid soil Rhiannon flecking of the bark can occur and I must stress that Damsons do prefer an alkaline soil. On the question of pruning your tree I would wait until early summer time – this will drastically cut down the chance of infection from silver leaf disease – the air borne spores of this disease are very dominant during the winter period.

L Frost asks…

I think I have a problem with my damson tree. I only planted it in October and it has been doing well. Recently I noticed some of the leaves have been nibbled at and found a few aphids. I have also put down some slug pellets as they have been eating my lupins. I visited my local garden centre for some info but not much help. I used some soapy water, but now quite a lot of the leaves have a rust appearance on them.

With your Damson being a fruit crop I always reluctant to recommend any insecticide sprays and you will usually find that the aphids do not cause large amounts of damage. You mention the rust appearance on the leaves and I am sure that this has been cause by the recent adverse weather conditions. If however you do decide to spray to control the aphids it is important to use one of the safer organic sprays.

PLUMS

Ellie asks…

We have a Victoria plum in our garden, at least 20 years old, I understand. After 2 years of great fruiting, we noticed that the lowest branch is completely dead this year, with grubs under the branch and holes like woodworm all over that branch and extending up the vertical trunk too. I sawed off the dead branch before reading your pruning advice (but I will cover it with a sealing product tomorrow, weather permitting), and before noticing the spread was so far up the apparently healthy part of the tree. What am I dealing with, can I stop it, and will the rest of the tree survive?

It is important Ellie providing that the weather is fine that all the branches which you have pruned on your Plum Tree must be sealed using a compound such as Arbrex, as this will cut down the risk of infection from the air borne spores of the Silver Leaf Fungi. And I would also use the sealing compound on the cracks and holes which are further along the trunk.

Mike Tansey asks…

I have a Plum tree that is very old but every year since we moved here 5 years ago it has borne good fruit. The branches are now too long and crossing over each other. I plan to prune it in June but don’t know where to start. It’s main branches are shaped like a Y with lots of smaller branches coming from it in all directions. It’s about 8/9 feet tall.

It is important Mike that you prune your Plum Tree during June/July as this will cut down the risk of Silver Leaf Disease and as the branches of your tree are becoming crowded, some of these can be pruned back but, it is important not to over-prune. Plums will tolerate a more crowded centre than Apple or Pear Trees. It is also worthwhile to remove any spindly shoots, and some of the main branches can be lightly trimmed back but, again it is important not to over-prune.

Lucy asks…

We have an old victoria plum tree and next to it, along the fence are 4-5 damson “trees” that almost look like a hedge. They bear almost no fruit, unlike the plum tree. Our neighbour tells us that the damson are killing the plum tree, as they are simply suckers from the original damson root that the victoria plum was grafted onto. He advises pulling up the damson plants to give the plum tree the best chance of survival – he has seen it weaken over the years. I had not heard of this before. Is he correct – should we take out the damsons?

Your old Victoria Plum tree Lucy will have originally been grafted onto a root stock – the most popular ones at that time were St Julian A (semi vigorous) Brompton (vigorous) and both these root stocks do send up suckers from soil surface and these could easily be the damson shoots which you are talking about. Suckers from root stock produce very little fruit. The suckers will be taking nutrients from the soil and will also be restricting the growth of your plum tree and, as your neighbour suggests, it would be far better to dig out these suckers. You can always trace these suckers back to check if they are coming from the original root stock.

W C Morgan asks…

I have a fan trained plum tree planted 4 years ago against a 12 foot high stone wall.
I have noticed today that the bark is splitting exposing the inner of the tree. What can I do about this, if anything!

Plum Trees are susceptible to Silver Leaf Fungal Disease. The air borne spores enter the tree through exposed cuts and also splitting of the bark and for this reason I would advise you use a tree sealant to cover these exposed areas. Quite a number of these sealants are bitumen based and one of the popular products is Arbrex Seal and Heal which can be obtained from Garden Centres and DIY Stores. You will however need to wait until we have a dry weather period before applying the sealant.

Vera asks…

My two year old dwarf plum tree only produces leaves at the tip of bare spindly branches. How do I correct this and what is the cause?

Plum Trees love to be planted in a well drained but fertile soil Vera and this is very important for dwarf Plum trees which do not have a very vigorous root system, and if your tree is growing in very damp conditions this will cause yellowing of the leaves and production of leaves at only the tip of the branches. Your Plum tree is only two years old and you will need to prune back the spindly branches to form the correct structure for your tree. Also, to avoid infection from the Silver Leaf Fungal Disease you will need to prune the branches back early summer time to approximately half the size.

Tricia Flowers asks…

I have had a plum tree for a couple of years but before the end of the Summer the leaves curl up and discolour dark brown areas. The tree didn’t bear any fruit last year and two plums in the first year we had it but I’m assuming this is because it is too young?

Plum Trees are the earliest flowering of the fruit trees Tricia and this makes them more vulnerable to frost damage and this could quite easily be the reason why you have had no plums on your tree. It is important not to plant Plum Trees in a frost pocket. Regarding leaf curl and discolouring this could quite easily have been caused by last year’s long hot summer – which caused many trees to drop their leaves prematurely.

Jon Howard asks…

In the garden of my late grandfather there is a lovely plum tree (think it is a Victoria). The tree is far too big to move but for sentimental reasons I wondered if I could take or cutting or similar and establish my own tree. Assuming it is possible how would I go about such a thing?

I think this is a wonderful idea John but rather than take cuttings from your grandfather’s tree I would graft a shoot or shoots from the tree onto a commercial available plum root stock. The root stocks available are Pixie (which is semi dwarfing) and St Julian A (which is semi vigorous). The two must popular methods used for grafting a fruit tree are whip and tongue grafting which is carried out during early springtime and chip budding a fruit tree which is carried out during late summer. It is difficult for me to explain the techniques by email and it would be easier to ask an experienced gardener to show you the techniques or contact your nearest Horticultural College or Gardening Society.

Colin Coombs asks…

When should Victoria Plum trees be pruned?

Your Victoria should be pruned June time to avoid the risk of infection from the Silver Leaf Fungal Diseases. Very little pruning is required except for thinning out overcrowded shoots and again dead and diseased shoots need to be removed. Any pruned stems would be better treated with a tree sealant such as Arbrex.

Chris Poor asks…

I am about to buy a Opal plum tree on Pixie rootstock, however the supplier states it is self fertile, but the RHS web site states it is partially self fertile. Which is right and should I have a problem with pollination? I only require the one tree.

If you require only one plum tree Chris you will obviously need a self fertile variety and with reference to the Opal variety plum tree you intend to buy, in Ken Muir’s Fruit Growing Catalogue 2006/7 Opal is classed as a self fertile variety and, also in the RHS Fruit & Vegetable Garden Book – which is an excellent reference book – Opal is also listed as self fertile and from further information I have received again, Opal is a self fertile variety. When planting your tree try and avoid frost pockets, plums are early flowering and can be sensitive to frost damage.

Eva asks…

I was bought a plum tree two years ago, I just placed it in a space, it has fruited, but I would like to move it a more convenient spot, it is a Victoria. Is this possible and when is the best time to try this?

The time to transplant your Plum Tree Eva is during the dormant period providing the ground is not too wet and also not frosty. January/February weather permitting would be ideal and you will need to ensure you dig out a good sized root ball when lifting. Never plant in a frost pocket and Plums also prefer a well drained soil – they do not like wet feet.

Pauline asks…

We planted a Victoria plum tree a year ago in our garden. How do we look after it in the winter months?

You can sit back and relax during the winter months Pauline – all you need to do is after some windy weather check that the roots of the tree have not worked loose and just gently firm the soil around the tree. In the spring time I would feed your Plum Tree with a general base fertiliser such as GrowMore of Fish Blood and Bone Meal and if possible, your tree would appreciate being mulched around the roots with some well rotted manure. On the question of pruning the time to prune your tree is early spring/summer time to avoid infection from Silver Leaf Disease. If the basic structure/frame work of your tree is already established very little pruning will be required and all you may need to do in future years is to thin out some overcrowded branches.

Stephen asks…

I have a plum tree growing in my garden, and have had a large crop of fruit this year. However a large number of mushrooms have grown on the tree over the last month or so. What does this mean and how do I get rid of them? Any advice would be appreciated

The toadstool/mushrooms growing at the base of your Plum Tree Stephen are the fruiting bodies and these produce spores which are then dispersed and form fine spider like strands which are called Mycelium – this is the vegetated part of the fungi which lives on decayed matter – dead tree stumps and roots – and it is the Mycelium which produces the toadstools/mushrooms. To stop the toadstools/mushrooms spreading you will need to remove them by hand before they disperse the spores. The fungi which gardeners’ fear most is the Honey Dew Fungi (Boot Lace Fungi) and they will feed on live roots and can seriously damage trees. The toadstools are amber in colour. If your require any further information please email me again at BBC Radio Lancashire.

Marea Campbell asks…

I have a large purple king plum tree that must be over 30yrs old. I notice that in places where I’ve pulled back the bark it’s full of ant nests and wood slaters. It has a bit of wood rot inside the truck also. What’s the lifespan of this kind of tree? Is it worth keeping? It still bears fruit.

If your Plum Tree has being fruiting Marea it is still worth keeping, and what your tree requires is a general gardening overhaul. I would start by removing the wood rot inside the trunk and I would fill the hole with a plastic bitumen filler – this will help to stop infection from bacterial canker. I would also remove the ants nests as the ants will be damaging the bark and when your Plum Tree is fully dormant I would spray the trunk with a tar oil winter wash which will kill any pests/predators harbouring in the crevices. The tar oil winter wash can be obtained from any Garden Centre. If you need to prune your Plum Tree this needs to be carried out in the summer months to cut down the risk of infection from Silver Leaf Fungal Disease.

Ken Aspden asks…

Three seasons ago I planted a young Victoria plum. It had some fruit that year but has not had any the last year and it does not seem to have any this year. The plant seems quite healthy.

Plum trees are the first of the fruit trees to flower Ken which makes them susceptible to frost damage and this could quite easily have been the problem this year. It is very important with Plum trees to ensure you do not plant in a frost pocket and I would also be inclined to give your tree a feed with a high potash fertiliser which will harden the shoots off and encourage flowering. Victoria Plum is self fertile so you will not require another tree for pollination purposes and I am sure when your tree has ‘settled down’ it will produce the fruit.

J N Leonard asks…

Can a successful Victoria plum tree be grown from a rooted sucker?

It really is not worthwhile trying to grow a plum tree from a rooted sucker which will have come from the plum root stock onto which your Victoria Plum has been grafted. The two most popular root stocks used for plums are St Julian A and the new dwarf stock Pixy and it is more than likely that your sucker will have come from one of these two root stocks.

Kate asks…

We have just moved into a new house with three plum tress. Most of the fruit is infested with small maggots. What can I do about this problem for next year?

A serious pest of the Plums Kate is Plum Sawfly and the tell tale signs are a tiny hole in the Plum which is surrounded by a sticky glucose substance and inside the Plum is a creamy white grub which is the grub of the Plum Sawfly, and I am sure that this is the grub you are having problems with. What you will have to do next year is to spray your Plum Trees approximately seven to ten days after petal fall – using a contact insecticide and hopefully the insecticide will kill the emerging grubs of the Sawfly before they have chance to enter the young plums. For this year it is important that you collect any infected plums and disperse of them.

Cheryl Oates asks…

Dear Bill, we have a plum tree in the far left corner of our garden. The roots shoot up into the lawn. Over the past three years we have mowed the lawn taking the tops off the root shoots. The roots below are becoming stronger and this year really spoiling the lawn. I want to dig them up and cut them right back as far as possible. This will cause a lot of disruption to the lawn – is there another option? Hope you can help.

What happens with Plum Trees and other prunus species such as Cherries Cheryl is that they all produce large roots – spreading just below the soil surface – and this can cause immense problems on pathways – garden areas and in your case on lawns. There is no easier answer to the problem, if you cut the main roots back they will start to shoot again and this is going to be detrimental to your Plum Tree. The bottom line therefore is that you may have to make a choice between your lawn and your Plum Tree.

Terry Griffiths asks…

I have a Victoria plum tree which has done well this year, I do have some saw fly infestation, but not as bad as previous years due to me hanging up a trap to catch the male fly, the problem I have is the fruit is going bad on the tree and withers away, they have a purplish bloom on the plum I recognise this as the plums that are going to rot, can you please tell me what your thoughts are on this problem.

It sounds as though your Plums Terry have been infected with Brown Rot which is a fungal disease. The fungi can gain entry through wounds in the fruit ie. birds pecking and Sawfly holes and the spores of the fungal disease can be easily spread by birds, rain splash and insects and the plums deteriorate very quickly and become shrivelled. You need to remove the infected fruit to stop the infectious spores and you will also need to remove any fruit which as dropped on the floor.

Dennis Cooper asks…

I have planted a Pixy Victoria Plum in a well drained pot, but as yet no sign of life. After the second week in the pot sap started to run down the branches. I water it regularly. Could the tree be dead?

It looks as though your dwarf Plum Tree has died Dennis because by now it should be in full leaf and actively growing. The sap which is now running down the branches sounds very much like as though your tree has been infected with bacterial canker. It would be worthwhile though cutting one or two small pieces off the branches and if these are completely brown then unfortunately your tree has died.

Bob Whiting asks…

Two plums, one pear, one apple tree all stand about 5ft high. The Pear loads of blossom result: loads of Pears. Apple loads of blossom, fruit not yet showing. 1st Plum not much blossom or show of fruit. Second Plum Loads of blossom and about eight plums showing. Have the birds eaten the young plums or can I expect more to show later on?
Because of wildlife I’m loath to use slug pellets around my beans. I have lost 15 to slugs and snails. Some say copper strip/pipe placed around the plants as a barrier will stop the slugs/snails from getting at the plants is there any truth in that?.
Is there a gardening book that shows flower, root and leaf structure? I’m having no luck in identifying the shrubs and some of the flowers? Many thanks.

Hi Bob on the question of your fruit trees your plum trees will be the first to flower and could have quite easily been affected by the late frost. If your apple tree if not self-fertile it will require another tree of a different variety for pollination purposes but I am pleased to hear that your pear tree is ‘doing the business’. I am almost certain that the variety of your pear is Conference which is self pollinating.
You are correct about the copper strip – it will stop the slugs eating your plants. What happens is the slugs try to slide over the copper and get a shock. The copper strips – mats and tape are available in most Garden Centres and DIY Stores.
On the question of gardening books the Royal Horticulture Society produce a wide range of books but one of my favourite reference books is ‘The Complete Book of Gardening’ edited by Michael Wright and is a Mermaid Book.
——

Frank Parratt asks…

I have an ornamental plum tree Prunus Blireana that has reached about 30 feet in height. Please when is the best time of year to have it pruned?

To cut down the risk of infection from the disease Silver Leaf (which is dominant during the winter months) and attacks all trees of the Prunus Family the best time to prune your Plum Tree Frank is during the summer months – preferably June/July. The spores of the Silver Leaf fungi are airborne and they enter the branches which are damaged and also from pruned branches Therefore, to avoid infection I would treat the pruned branches with a recommended Tree Sealant.

Jackie asks…

Hi Bill, I have just bought a victoria plum tree could you please advise the best place to posiiton in the garden and what type of soil and disease treatment it will need to flourish.

Your Victoria Plum Tree Jackie needs to be planted in a sunny sheltered position in a well drained soil, and with them being early flowering you need to avoid planting in a frost pocket. With your tree being newly planted you will need to keep an eye on the watering over the summer months and it will need regular feeding with a general base fertiliser. Little pruning is required in the early stages of growth but any pruning that is required is far better carried out during July as this will avoid infection from the Silver Lear air borne fungal disease.

Ferzana asks…

Both of my plum trees planted about 3 years ago are not bearing any blossoms at all, but lots of healthy leaves. Any ideas on how I can encourage the trees to produce fruits?

It is important with Plum Trees Ferzana that they are planted in a warm sunny but well sheltered site. They do produce flowers early so it is important to avoid frost pockets. With regard to your two Plum Trees not flowering I would avoid any pruning and I am sure that in the not too distant future your trees will produce blossom. Plum Trees will grow in a wide range of soils providing that the soil is not waterlogged over the winter period and I would be inclined to use a general base fertiliser rather than straight potash when feeding.

Alan Young asks…

Just removed 2 old Victoria plum trees 25/30’high. I think they could have had silver leaf. The trunks and branches had a darker core. I’d seen ‘elephants’ toenails’ on them in the past 8′ up and near base. Many branches had broken last year partly because of the crop but they rotted on the tree. Have grubbed out the roots with a digger, leaving BIG holes, as I want to replant Victoria, Marjories Seedling and a Merryweather damson. There was a lot of sawdust from the chainsaw and broken small roots and branches lying about, despite my best efforts to clear it up before the digger came. Is that a problem? Under the base of one the tree was crumbly.

Providing that you have removed most of the branches Alan the chances of infection from Silver Leaf are very slim but, my only worry is the replanting of Plums and Damsons in the same soil which is not good horticultural practice. If at all possible I would try and work in some new top soil incorporating some well rotted manure before replanting.

Damsons, pruning & container growing

Pruning & Aftercare

Pruning Damsons is the same as for plums and gages, as follows and will depend on the form of tree you are growing. Order Damson trees by clicking here!

THE DWARF PYRAMID

This is by far the best trained form for plums and cherries if you require your tree to remain an easily manageable size. Plums can even be grown in a fruit cage using this method and all trees are easily netted from birds, which is very important with cherries. After planting the tree it can be left until the Spring and as growth starts the main stem should be cut back to 4 feet from ground level. This may have been done at the nursery before despatch. During the Summer, usually in late July, all of the new side branches should be shortened to about 8 inches, pruning to a downward pointing bud, the leader (main stem) should be left un-pruned. If the side shoots appear too close together, remove some completely to leave a well shaped tree. All shoots below 18 inches from the ground should be completely cut off.

Following Spring & future seasons As growth starts in the Spring, the leader should be cut back by about half to two thirds of the new growth, pruning to a bud the opposite side to the previous year’s pruning. In future years when the tree has reached the required height of 8-9 ft the leader should be cut back in May to control at this height. In Summer each year all of the current season’s growth of each branch should be shortened to about 8 leaves, all laterals growing from these branches should be pruned to 6 leaves, any vigorous shoots near the top of the tree should be cut out.
Your tree is now maintained in an easy to manage heavy cropping form

The fan trained tree

Start with a young year old tree and immediately remove the top third of the growth. If it is feathered prune just above two conveniently placed branches; these will form the basis of your fan. Normally this is about 18” from the ground but it will depend on the positioning of 2 good feathers which you can use. It can also be varied to your own preferences and there are not hard and fast rules as to where the first branches should be – sometimes a fan will be grown with a short leg and other times it may be branched quite close to the ground. If your trees is an unfeathered maiden and does not yet have side shoots then prune to just above 2 good opposite buds and these will form your first laterals from which to work.
The first Spring shorten these two laterals to about 10-12”. You will now have a tree that looks a bit like a stumpy capital ‘T’ but don’t worry. This is a good basis from which your fan will develop. These two shortened side laterals will now produce several new upwardly mobile leaders during the course of the growing season. Leave them be until the next Spring and then stand back and survey your tree. Most of the work will now have been done but you will need to remove any new growths that are heading towards the wall or fence and any that are crossing or too congested. Having done this you should now have a nicely balanced tree – confratulations, your fan shaped tree has been trained!
Later that summer, and in subsequent summers, you can shorten again a selection of less importasnt laterals and you can also trim the top most growths so that the tree stays within the boundaries of your wall or fence. Finally, in Autumn of the same year trim again the laterals that you shortened earlier in the summer, to about 3 pairs of leaves. You will find fruit buds will form on these shortened branches to carry next years crop.

The columnar Damson tree

Is the easiest growing method to prune. Pruning takes place in the second half of the summer and is simply a matter of trimming back all of the side growths to about 3”. Established trees only need to be pruned once a year but young trees show more vigour and you may need to go over them again in late Autumn. In subsequent years the practice is continued late each summer. Flower buds form on the base of the previous years growth. The leader can be shortened once a year, at the same time, if desired and to keep it within an acceptable height. This promotes better branching lower down and a new leader will form from a bud just below where you cut.
If you tree has any bald patches along the trunk, which can happen especially lower down, you can encourage dormant buds to shoot by nicking the bark with a sharp knife just above the bud. This often encourages them to shoot.

Feeding & Irrigation

Although you will have fed the trees initially to get them going by applying fertilizer when you planted the trees, this will last only a short time. You will need to re-apply annually to get the best results from your trees. The type of feed you are giving will change slightly now as their requirements will be slightly different.
For the first year or two following planting I recommend a nitrogen based fertilizer. Nitrogen encourages growth, not fruit, and that’s what you want during the formative years, as you want the tree to concentrate on building a strong framework for it’s fruiting years that follow. Feed nitrogen in early Spring, applied when the ground is damp or wet, at a rate of 2oz’s per square yard. It should be spread around the base of the tree. After this period, from year three, switch to a more general purpose fertilizer such as growmore or bonemeal, spread over the rooted area at two or three oz’s per square yeard, applied in late winter or early spring.
Irrigation is important for the health of the tree during the first year or two to continue establishment. But it is not so important afterwards so unless the tree is showing stress during prolonged dry periods it should not be necessary to give extra water.

Thinning of fruit

This is not really practiced for Damsons because the fruit doesn’t get that big anyway, seldom as big as a dessert plum so the benefits of thinning Damsons are fairly osbsolete unless your tree is prone to biennial cropping in which case thinning the fruit by a quarter soon after fruit set can offset this tendency.

Bugs and diseases of Plum trees

The Damson often seems hardier and less prone to disease than plums, but under certain circumstances the tree can succumb to any of the maladies that account for Plums.
Aphids and Whitefly
Are the commonest problem you might encounter. They can quickly infest soft new growths causing them to distort and to stop growing. Most insecticides will be effective, Provado is the recommended name; it is systemic which means although it kills on contact it also works from within the plant tissue, and can remain effective for up to 6 weeks before it is necessary to re-apply. Soapy water can be effective on smaller colonies.

Varieties to choose from

There is quite a limited range of Damsons and to be honest not a lot of breeding work has been carried out; Blue Violet is one of the very few to have come through recently. This new variety is typified by largeish beautiful blue skinned fruits, the flesh is sweeter than most Damsons and can be eaten fresh but of course is also ideal for all culinary purposes. Semi-compact in growth, self fertile. Likely a Damson-Plum hybrid.
Shropshire ‘Prune’ Damson
This is our most popular variety has it has the deep and powerful true taste of a real Damson. Definitely only for cooking, it makes superb jams and pies. The fruit is small, ripening to a deep purple-blue, almost black with a golden flesh. The tree is fairly compact, dense and twiggy with lots of short side spurs. A very hardy grower and a prolific cropper. Self fertile.
Farleigh Damson
Dense and compact, almost congested growth; needs careful pruning. Good flavour, fruit is medium blue-purple. Does well in Northern area’s, partly self fertile but the best crops will be attained with a pollinator.
Merryeather
For centuries a famous name in Damsons. The fruits are larger then the Shropshire Damson and milder in taste – good for cooking purposes but some can eat them fresh as well. Self fertile and a good ‘doer’ growth tend to me more vigorous than most.
King of the Damsons Large, dark purple black fruits, rich and juicy golden flesh. Hardy and vigorous grower. Not often grown but good, the blossom is self fertile.

Growing Damsons in containers

These fruit trees can perform very well in a container, if anything being even more satisfactory than the Plum. This is partly down to their naturally compact habit – they seldom show as much vigour as young Plum trees. Provided the Pixy rootstock is chosen then the trees will perform well in a standard 24” container using a loam based compost, the preferred choice of trees for pot.
The trees can be set in the container during the winter months from bare rooted stock, or the summer as long as the tree acquired is already in a pot, it can be transferred then to your larger one.
Additional feeding on an annual basis should consist of maxicrop seaweed feed, applied as a foliar feed or in granulated form. Customers have reported good results from Miracle grow.
The trees can remain in the container for 5-7 years after which time they must be re-potted. You can increase the size of the container by 4-6” or get a good half barrel at this point; alternatively, you can undertake judicious root pruning, by this time the rootball will be fairly congested so it can be ‘shaved off’ with a sharp knife or you can loosen it and shake off some of the old compost. It can then go back in the original pot, with new compost around the roots. This method should only be undertaken during the winter months when the tree is dormant.
Trees in containers require regular and reliable watering and Damsons are no exception. Twice a day may be necessary when it is hot, once a day should be adequate at other times and especially in the Spring and Autumn when night time temperatures are cooler and the moisture does not evaporate so readily and the trees’ requirements are less anyway.
All varieties will be suitable for container growing as long as the Pixy rootstock is chosen, and you can grow them as bush or column type trees. The more vigorous St Julien stock can make a satisfactory container specimen, with judicious pruning, in a large half barrel or similar, if a larger tree is required but Pixy should normally be the preferred choice.

Patch notes/Horizon/1.4.0

Architect is a major portion of this update. The concept of Architect is to give Horizon a foundation to make building up multiple settlement easier, more fun, and look way more awesome. I want the option to be able to actually REBUILD The Commonwealth. More Patch notes.. Now that we have a good foundation and large buildings to put things in, the next update (v1.5) will probably contain more settlement progression. I want settlements to actually feel like you’re rebuilding The Commonwealth, and visually be able to see it happen. A new optional death/revival mechanic is addded to Horizon, to partially remove the cheesy feeling of “dying and reloading save games with all your stuff restored with no conscequences other than losing real time.” This system is still in beta testing, but you can choose to enable it in the Horizon holotape settings. (I may default this feature to ON in the future once it’s tested more.) I would really appreciate any testing and feedback on this update: – Is there any textures or meshes missing? (possibly due to me missing something in the BA2 archives) – Is there any issues with placing or removing structures in Architect? – Any problems when dying and reviving in a settlement? – Any issues with the Caravan Hub travel system? – Any issues with newly placed Water Purifiers or Vendors? – Any feedback or reports is appreciated. Thanks! (NEW) Player Revival (BETA Testing) – Upon normal death, you’re instead incapacitated, where you’re dragged back to a settlement by either your companions or settlers – You can choose to enable this new mode from your Horizon holotape settings – The closest settlement to your last known outdoor location is choosen – If you have no settlements, it will revive you at Vault 111 (I may change this later) – When you awaken, you will have only 25 health – If you die with 1000+ radiation, you’ll awaken with 970 rads (I may change this, but for now, it works) – You lose the amount of caps based on your health/rads restored (currently its set to the same as doctors charge) (Keep in mind this is a beta feature, I still want to add more depth to this system, such as limitations of settlements based on certain conditions, and more penalities so you can’t abuse the system in certain cases. But I’d like to test it as-is for now.) – NOTE: Just because the system allows you to bypass the need for reloading saves, doesn’t mean you shouldn’t save your game OFTEN. The game can crash. I may even implement an auto-save feature in the next updates. – WARNING: Don’t kill yourself with rad overdose inside the pipboy, or it gets stuck there. Resource Manager – Crops are measured in terms of “Rating”, where some types give better ratio of “rating per food” than others – You now always produce crops at 5% of the “total rating” of each crop (without fertilizer) – You now produce extra crops at 5% of the “total rating” of each crop (using fertilizer) – These values look smaller, but they are actually double the potential crops if you use the new crop types – Vanilla crops will produce roughly 2x less in total (regular production and fertilizer combined) – Crops for production should now only count if you actually own the settlement Settlement Crops – All vanilla-placed crops are scrap-only, and will give you 1 crop now when you scrap them – Regular crops are now only worth 1/4th the value for production (both settler rations and fertilized production) – Regular crops still give 1 “food” per plant for settlers (note that “Food” is NOT the same as “Production Rating”) – Tarberries are added to the resource manager now – Tarberries are worth more production rating than other crops (enough to get +1, and another +1 with fertilizing) – Planting “Domesticated Crops” is changed (see further down) Obsolete Objects in Horizon – WARNING: All Horizon-specific objects listed below will be phased out: – Vendors / Defenses / Decorations / Beds / Water Pumps / Power Generators / Caravan Hubs – These objects will continue to function for a few patches until I remove them in the future – All of these objects can be replaced with Architect – Scrapping all of these objects should refund you the FULL amount of all materials, so you can replace them Settlements – Standard Small Power Conduits/Pylons now give 2x the range for lights – Large Power Pylons now give 4x the range for lights – Fixed a few bugs with Armor and Clothing stalls for tracking traders – Vanilla Tier-1 and Tier-2 Doctor stalls now require 2 vendor contracts and 100 caps – Homemaker doctor stalls are updated for this change also (NEW) Workshop Menus – Horizon now has it’s own menus in the workshop – Resources->Utility: Resource manager, command table, mailbox, etc. – Resources->Job Stations: All job stations – Resources->Production: All Horizon production devices – NOTE: Currently there is no uninstall for this if you remove Horizon (Horizon was never meant to be uninstalled from an active save game, but I may add the menu uninstaller later) Crafting Stations – A weapon lab and robotics lab were added to the RR HQ and the memory den – Weapon labs were added to a few indoor raider-based areas Vault 81 – Now has crafting stations – The middle oven in the kitchen area is a clean version of the new kitchen stove – One of the storage rooms is converted into a crafting room, with armor and weapon workbenches – A robotics lab is located near the generator room – The medical lab has the new vault-style chemistry station (NEW) Scrapping Tools (BETA) >> Please note that this is brand new, so it may need some testing – This kit allows you to scrap junk items in your inventory into raw components – Use this kit from the AID tab, and then exit your pip-boy – You will get a pop-up message to press a button and turn your items into scrap – The scrapping process averages 5-15 seconds depending on the amount of junk – Crafting the kit requires either Scrapper rank 1, or Settler Skills: Salvaging rank 1 (NEW) ZX-1 Experiementation Lab: Weapon Tinker Kits – These kits are used to gain Weapon Crafting Skill more quickly in the ZX-1 Experimentation Lab – Tinker kits can be used in the ZX-1 lab under “Tinkering” – Each kit grants 50 skill and some experience points – Each kit requires a large assortment of materials (you need to scroll down the list when you craft it) – Some of the materials required include: grade-1 alloys, adhesive, many pipe weapon parts, tools, and other components – They are crafted in the Robotics Lab under WORKSHOP Crafting – (NEW) Adhesive – Craft bubblegum, beer, acid, and hubflower into 2 adhesives (requires Survivalist rank 2) – (NEW) RadAway Chew – Removes 50 rads slowly over time (requires Survivalist rank 2) – (NEW) Supply Kits: Craftable using Mutfruit, Melons, Tatos, and only 1 water (the melons hydrate) – Requires Local Leader 2 – Supply Kits that use settler rations, require Local Leader 3 now – Supply Kits can also be assembled in Cooking Stations now too – Clean Bottles now give 5 per craft, and require liquid fuel instead of oil – Maintanence Kits now give 5 per craft, and can also be crafted in the Cooking Station – Military Kits now use Supply Kits instead, so you’re not forced to use rations only for food (they’re also slightly cheaper to craft this way for Local Leaders) – The single-use Cargo Bot caller device no longer has any perk requirements (other than placing one of the scrap storage objects) – The single-use Cargo Bot caller in the contracted work tab is removed – The multi-use Cargo Bot caller requires more materials now to craft, and also requires Robco Secrets rank 2 – The single-use Memory Device no longer has any perk requirements – The single-use Memory Device in the contracted work tab is removed – The multi-use Memory Device requires more materials now to craft, and also requires Fact or Fiction rank 2 (NEW) Grenade Swapper (BETA) >> This is a proof of concept item I’m testing, but it’s available for you to try out – Using this device gives you a popup menu to select a grenade or mine in your inventory – Inside the menu, you’ll find an option that you can toggle to make grenades/mines automatically throw as soon as you press the button – This device can be crafted in the weapons lab, and is located in the AID tab – You can add this item to your favorites bar Icons/Tagging – New icons are added to some items so they look nicer and you can spot them faster – Tags in the AID tab are rearranged to sort categories better, but still have an order of importance – Category order: Meds, Cures, Buffs, Tools/Devices, Chems, Water, Drinks, Food, Crops, Liquor, Prewar, Raw, Wild, Junk (I consider all the stuff on the bottom as junk you throw into your settlements, so its easy to scroll down and just chuck everything upwards into a container really fast) Items – (NEW) Sealed Literature Package: A sealed package that contains a random guide or magazine – (NEW) 5 volumes of books are added to expand the “Unstoppables” magazine recipe perk – (NEW) 5 volumes of books are added to expand the “Amazingly Awesome Tales” magazine recipe perk – The misc item for Beryllium Copper is properly labeled – Atomic Scotch and Jet Coffee only give 1 per craft now – The Trailblazer’s guide is renamed to “A General’s Guide to Leadership” – (NEW) “Prototype Acid Canister”: can drop from legendary humans above level 15 – Charge Cards are labeled as “Currency” and are no longer scrappable – Pre-war money is labeled as Currency instead of crafting material – Some Nuka World items are labeled as Currency (NEW) Dynamic Magazines >> Static placed magazines often ruined part of the exploration aspect for many players. So now, many magazines are now random to help remove that “meta-gaming” knowledge of knowing where stuff already is. – Many vanilla pre-war Magazines that are placed around the world are now randomized loot – Not all placed magazines are replaced – Magazines are replaced with a “Sealed Magazine Package”, which has it’s own envelope style package graphic – “Sealed Magazine Package” will always give a vanilla pre-war magazine, and not a Horizon guide – “Sealed Literature Package” are different, and located in other sources, and contains random guides or magazines (NEW) Micro-Drone – Hand launch a small drone that flies slowly until it impacts a target – Explodes for 175 damage – Requires Robotics Expert rank 1 and Demolition Expert rank 1 – Settler Engineer missions can sometimes make you Micro-Drones – (This device is intended to be a seeker, but I can’t get that working yet with grenades) (NEW) Pipe Bomb – Grenade-style explosive that deals 65 damage – Requires Recipe: Inconceivable rank 1 – Drops from some loot that can drop grenades – Some raiders and super mutants can carry these (NEW) Pumpkin Fire Mine – Mine that deals 35 damage plus 60 fire damage over 30 seconds – Requires Recipe: Inconceivable rank 2 (NEW) Handmade Frag Mine – Mine that deals 85 damage – Requires Recipe: Inconceivable rank 3 – Drops from some loot that can drop mines (NEW) Unknown Improvised Enemy Mines – While rare, a few improvised mines are placed in some Commonwealth interiors.. watch out! (more may be added later) Weapons – The pipe gun should properly show the .223 ammo count on top, and the other ammo counts should be shifted correctly now – The 12.7mm ammo requires higher rank perks now – Fixed the “Outdated” receiver on the Submachine Gun, in case you somehow still have or find an old SMG – Fixed some NPCs from possibly dropping the old damaged weapons – Possibly fixed smg sound effects for some people (I can’t test this, because I don’t have the problem) – : Vendor-sold missile launchers should now always roll as “good condition” – Scrapping some heavy melee weapons give more materials – Scrapping Synth Blades now gives laser parts – Scrapping the Micro Sledge now gives baton materials Survival – All thirst levels are pushed up by 8 hours, but everything still requires the same amount of water per hour of time passed – The first thirst level is now 16 hours (up from 8) – Each additional thirst level is every 8 hours after (NEW) Trap Disarming >> Many traps and mines now require skill (perks) to disarm them, but with some freedom in choices – There are 4 classifications of traps: Basic Traps, Basic Mines, Class-1 Tech, Class-2 Tech – Basic Traps can be disarmed with: Master Thief 1, Hunter 2, Technologist 1, Sneak 2, or Recipe: Covert Ops 4 – Basic Mines can be disarmed with: Demo Expert 1, Master Thief 1, Technologist 4, Sneak 4, or Recipe: Covert Ops 6 – Class-1 Tech can be disarmed with: Science 1, Technologist 2, Master Thief 3, or Recipe: Covert Ops 8 – Class-2 Tech can be disarmed with: Science 3, Technologist 5, Master Thief 4 Perk: Pickpocket is now “Master Thief” – Rank 1 now grants the ability to disarm Basic Traps and Basic Mines – Rank 3 now grants the ability to disarm Class-1 Tech Traps and Mines – Rank 4 now grants the ability to disarm Class-2 Tech Traps and Mines (I will probably add more benefits to Master Thief in the future) Perk: Sneak – Sneak level requirements are changed to: 1, 6, 12, 18, 24 – Sneak rank 5 no longer gives you magical invisibility, but instead gives you another 10% bonus to sneaking (I thought I did this months ago, I must have forgot it) – Reworded rank 3 to “moving at normal speed” instead of “running” so that it actually makes sense, since you don’t “run” while sneaking* *Many players often don’t understand the difference between walk mode and run mode, so hopefully this helps Attack Dogs – Your Attack Dog will now stay out for 10 mins (up from 5 mins) Companion Revival – The timers were reduced for how long it takes for companions to get back up after combat ends – (Keep in mind, I have plans to rework how companions are revived, but I’m not ready yet) Enemies – All insect type creatures have their endurance removed to match all other NPCs (please let me know if you notice any weird problems with this)* – All raider types and gunner ranks will now spawn starting at level 1** – Some legendary raiders should have the proper templates for faces *This includes DLC Ants and Crickets **Since the levels were mostly low as it was, I want to see if this helps fix distribution of types better Mutated Creatures/Parts (i.e. legendary) – Stingwings, bloodbugs, bloatflies, Yao Guai now have their own custom loot distribution for mutated parts – For many mutated creatures, the guaranteed part that drops is now more specific to that specific creature type – Stingwings: Always drops 1 Mutated Stingwing Stinger (new) – Bloodbug: Always drops 1 Mutated Bloodbug Gland (new) – Bloatfly: Always drops 1 Mutated Bloatfly Stinger (new) – Radscorpion: Always drops 1 Mutated Radscorpion Stinger (new), and sometimes a carapace or claw – Mirelurk King: Always drops 1 Mutated Poison Gland (new), and a carapace – Mirelurk Queen: Always drops 2 Mutated Poison Glands (new), and 2 carapaces – Yao Guai: Always drops 1 Mutated Yao Guai Fur (new), and sometimes some teeth, and 1 extra part above level 15 – Deathclaw: Always drops 1 Mutated Deathclaw Hand (same as before) – Glowing and high-tier Feral Ghouls: Now also drops a mutated organic part, in additional to the random prototype – Feral Ghouls have a small chance to give a mutated organic part for Hunter rank 2+ – Hunter rank 2+ has a chance of getting mutated parts from more creatures now (most are medium/large animals and creatures) – Hunter chance for mutated parts uses a better distribution of parts based on the specific creature – The weights on mutated parts are now setup based on the components – The radscorpion stinger drops 3 different poisons, which is loosely based on some real-life scorpions – The stingwing and bloatfly stinger drops 2 different poisons, which is loosely based on real-life bees/wasps Graygarden >> The crop plants in Graygarden were altered in order to fix numerous issues with them – All mutfruit plants are converted to “Withered Mulfruit Plants” which are small mutfruit-sized trees – All planters are coverted to “Withered” crops – All withered plants are static scrap objects, which can be scrapped for materials – Each withered plant will give 1 crop of the appropriate type, which you can use to re-plant a new crop if you wish – The vendors are updated to reflect these changes (requires a vendor recycle) (I feel these changes fit fine with the quest and the story behind Graygarden, so I don’t see it removing any immersion.) (NEW) Graygarden Robot Controller – A craftable AID item that can disable (or re-enable) the Graygarden robot animations – Located in the Robotics Lab under Workshop – This recipe only appears after you own Graygarden Armor – Horizon’s “No Weave” slot for ballistic weaves is now activated – Armorsmith’s “No Weave” slot is disabled in the patch, so there aren’t duplicates – The value of loose mods for weaves is increased – The value that weaves add to armor is increased – Ballistic Weave Mk1: DR reduced to 15 (from 20) – WARNING: Horizon still does not support the newer Armor Keywords and Armorsmith yet. This will come soon in the next patches. For now, use v3.2(?) Misc – (NEW) The memory den now has a wheelchair up front so you can use the doctor’s services before the basement is open – Reworded the Blacksmithing description – Fixed some texture mapping problems on the training desk – Renamed the old parcel package, in case you somehow still have a bugged one, so you know its just vendor junk – The shovel is no longer incorrectly added to the defui addon Sim Settlements Patch – Updated to work with the newer versions Scrap Everything Patch – (NEW) Now increases the height limits for settlement building to 10,000 units for all settlements – Increases the height range that settlers can sandbox around – Removed the ability to scrap graygarden pipes, and railroad tracks – Added the “Dead Tato plants” to a scrap list so you can now scrap them – Air ducts can now be scrapped – All animations markers are scrappable – Added bird markers to the animation marker list – Small rocks can now be scrapped (I cant test all of them, so let me know if any cause holes in the terrain – I still don’t allow large rocks/cliffs to be scrapped though) – Sanctuary: houses can now be scrapped (since you can easily place new houses now) – Sanctuary: steps, driveways, and footpaths can now be safely scrapped (none of them appear to have any bad terrain under it) – Sanctuary: Moved over that fallen tree (and 2 other trees) in the back leaning on the house, so it’s inside of the scrappable area now – Sanctuary: Adjusted a few dirt mounds so edges weren’t sticking out when you scrap foundations and steps – Starlight: You can now scrap the broken wing, and some of the pieces – Abernathy Farm: All buildings and the tower is now scrappable – Abernathy Farm: The wire connecting the electrical tower is disabled so isnt hanging there if you scrap the tower – Sunshine Tidings: All buildings are now scrappable – Taffington Boathouse: All buildings are now scrappable – The Castle: The small interior portal door was removed from the scrap list Places to be cautious of when scrapping everything: >> The following settlements don’t scrap well, so save your game and scrap only certain objects – Warwick Homestead (major problems.. scrapping the buildings leaves problem areas) – Croup Manor (minor problems.. but you can work around it as long as you don’t fall into the pits.)

Controlling Leaf Curl Plum Aphids – Leaf Curl Plum Aphid Treatment And Prevention

Leaf curl plum aphids are found on both plum and prune plants. The most obvious sign of these aphids on plum trees is the curled leaves they cause by their feeding. Fruit tree management is necessary for good production. Large populations of these pests can minimize tree growth and fruit sugar production.

Control plum aphids with a mixture of cultural and physical methods, with chemical formulas reserved for extreme infestations.

Leaf Curl Plum Aphid

Aphids on plum trees that are found inside curled leaves are leaf curl plum aphids. The pests are tiny and have shiny bodies that range from pale green to light yellow in color. The insect produces a high volume of honeydew, which is the excretion of the aphid. This in turn attracts ants that feed on the sweet liquid and causes a fungus to form that produces sooty mold.

Plum aphids cause leaves to curl as they suck the tree’s fluids. The eggs of the aphids overwinter on plum and prune trees but may move to other plant

hosts as adults. Leaf curl plum aphid treatments may help minimize fruit loss and increase plant vigor if the pest is properly identified and treatments begin at the correct time.

Aphids on Plum Trees

Damage to fruit trees by these aphids starts with the feeding on young terminal shoots. This can affect the growth of the tree and reduce the foliar canopy as the new leaves curl and die.

It is important to control plum aphids, as populations can quickly get out of hand and serious infestations drain plant reserves.

The aphids hatch just at bud break on the tree and begin feeding immediately on shoots and then on the underside of leaves. The curled leaves create a shelter for the pests. Early observation of the shoots can help indicate if you have leaf curl plum aphids and increase the chance of management of the insects.

Leaf Curl Plum Aphid Treatments

You can apply cultural methods to control leaf curl plum aphids. Use quick hard blasts of water to rinse off the insects. Limit nitrogen fertilizers, which force the formation of tip growth, one of the insect’s favorite plant parts.

There are also several biological treatments in the form of natural predators. Lady beetles, green lacewings and syrphid fly larvae are another way to control plum aphids.

If necessary, use dormant season chemical treatments of horticultural oil. Severe aphid infestations require growing season applications of a leaf curl plum aphid treatment such as neem oil, imidacloprid, pyrethrins or non-toxic insecticidal soap.

How to Control Plum Aphids

Apply superior type horticultural oil according to the directions in the dormant season. Spray in early November and then monitor the plant during the remainder of the dormant period. Read the manufacturer’s instructions for rate of application and amount of dilution.

During the growing season, once buds have broken, use repeated applications of leaf curl plum aphid treatment. Best results are found when you alternate one treatment with another to reduce resistance build up in the insects.

Brachycaudus helichrysi
(leaf-curling plum aphid)

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