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Apricot, Peach, Nectarine, Plum and Prune
Table of ContentsApricotCytospora CankersCystospora is a fungal infection occurring on the trunk and lower branches that usually enters through wounds in the tree. Twigs develop brownish-black areas around winter-killed buds or scarred areas on the bark. By early summer, a gummy substance appears, and later the bark separates from the wood. The cankers grow larger every year, and are most conspicuous on the main trunk or scaffold branches. TreatmentCultural control: As cytospora enters through wounds in the tree, your best defence is to control for peach tree borers (see below) and to avoid bark injury, long pruning stubs, winter injury, or brown rot injury to twigs. Prune trees in spring, not fall, and remove any dead wood before the end of June. Do not prune in cool, wet weather. Do not apply fertilizer after June. Healthy trees growing on well-drained, deep, sandy soil are less likely to get cankers. Chemical control: None are known at this time. | Top of Page | Peach Tree BorersPeach tree borers attack peach, nectarine, apricot and sometimes plum and cherry trees. | Top of Page | Bacterial SpotBacterial spot causes small, round, tan spots to appear on leaves which later turn purplish and angular. Small, sunken, round spots also appear on the fruit and later the fruit cracks. Extended periods of wet weather encourage the spread and development of the bacteria. TreatmentCultural control: Remove all fruit at harvest and remove infected leaves regularly. Chemical control: None are known at this time. | Top of Page | Brown RotBrown rot is a fungus that attacks various parts of the tree. Blossoms that become infected shrivel, twigs are killed, and fruit becomes covered with grey-brown mould and rots rapidly. Infected fruit may drop or hang on the tree throughout the winter, and mould can develop on the fruit even after harvesting. TreatmentCultural control: Throw all mouldy fruit in the garbage or bury it to reduce infection next summer. Cut dried fruit (mummies) out of trees when pruning and dispose of it in the same manner early in the fall. Chemical control: Spray when symptoms are first noticed and repeat repeat as indicated on the product label until late July. If brown rot is present and wet weather prevails, further sprays may be needed. Observe the product's no-spray interval before harvest. For up to date recommendations on pest management options consult local horticulturalists, Master Gardeners or your local garden supply centres. | Top of Page | NectarineCytospora CankerCystospora is a fungal infection occurring on the trunk and lower branches that usually enters through wounds in the tree. | Top of Page | Leaf CurlLeaf curl causes leaves to curl and reddish blisters to appear. Eventually, leaves turn yellow and drop. Tree is weakened if disease occurs several years in succession. TreatmentCultural control: Remove and destroy infected leaves as they appear in the spring. Chemical control: Spray either in spring before buds break or in autumn after leaves have fallen. Sprays are not effective at other times. For up to date recommendations on pest management options consult local horticulturalists, Master Gardeners or your local garden supply centres. | Top of Page | Oriental Fruit MothsThe larvae of oriental fruit moths are the worms commonly found in peaches and nectarines. Larvae overwinter on the ground in weeds and mummified fruit. They pupate in the spring, emerging in late May or early June as 6 mm grey moths with chocolate-brown markings on wings. The first larvae enter young twigs, which wilt and die. Later generations enter ripening fruit. It is a problem in areas where these fruits are grown commercially, and may not occur in isolated locations. TreatmentCultural control: Remove and destroy all infested fruit from under trees. Chemical control: Spray between July 1 and 10, depending on geographic location and repeat as indicated on the product label. Observe the product's no-spray interval before harvest. For up to date recommendations on pest management options consult local horticulturalists, Master Gardeners or your local garden supply centres. | Top of Page | Peach Tree BorersPeach tree borers attack peach, nectarine, apricot and sometimes plum and cherry trees. | Top of Page | Bacterial SpotBacterial spot causes small, round, tan spots to appear on leaves which later turn purplish and angular. | Top of Page | Brown RotBrown rot is a fungus that attacks various parts of the tree | Top of Page | PeachCytospora CankersCystospora is a fungal infection occurring on the trunk and lower branches that usually enters through wounds in the tree. | Top of Page | Leaf CurlLeaf curl causes leaves to curl and reddish blisters to appear. | Top of Page | Oriental Fruit MothsThe larvae of oriental fruit moths are the worms commonly found in peaches and nectarines. | Top of Page | Peach Tree BorersPeach tree borers attack peach, nectarine, apricot and sometimes plum and cherry trees. The adult or their larvae are seldom seen, but brown frass and gum appear on the trunk from the scaffold branches down to exposed roots, due to larval feeding. Gum may also appear at wounds and on winter-injured bark, which are entry places for the borers. Young trees may be killed. Older trees are able to survive light infestations for a few years but may also weaken and die unless borers are controlled. Adults are wasp-like moths that lay eggs around the base of the trunk in late summer and early fall. Caterpillars, 2.5-3.0 cm long with brownish heads, hatch and burrow into the wood. TreatmentCultural control: Wrap strong paper - not tarpaper - around the trunk of young, transplanted trees up to the lowest branch, and leave in place for at least two years after planting. Any pruning or accidental wounds should be scraped clean.If the tree is infested, remove gum and poke flexible wire into the holes to kill borers. Sterilize the hole with a solution of 1 part bleach in 4 parts water and seal with putty. Do this in the spring and fall. Chemical control: For established trees, spray bark of trunk and scaffold branches thoroughly, avoiding fruit and leaves as much as possible, beginning 10 days after petal fall, repeat as indicated on the product label. Correct timing is important, since only the adult can be controlled. When spraying, wear a long-sleeved shirt and pants; wash face and hands afterwards. For up to date recommendations on pest management options consult local horticulturalists, Master Gardeners or your local garden supply centres. | Top of Page | Bacterial SpotBacterial spot causes small, round, tan spots to appear on leaves which later turn purplish and angular. | Top of Page | Brown RotBrown rot is a fungus that attacks various parts of the tree. | Top of Page | Plum And PruneApple Maggots or Railroad WormsItalian and Stanley plums are susceptible to apple maggots, whereas other plum varieties are not. | Top of Page | Tentiform LeafminersAdult tentiform leafminers are tiny (3-4 mm long), brown and white moths. The larvae damage the leaves, creating speckled blotches of hollowed out, tented tissue. | Top of Page | Pear SlugsPear slugs are the larvae of sawflies and are not true slugs. | Top of Page | Peach Tree BorersPeach tree borers sometimes attack plum trees. | Top of Page | Bacterial SpotBacterial spot causes small, round, tan spots to appear on leaves which later turn purplish and angular. | Top of Page | Brown RotBrown rot is a fungus that attacks various parts of the tree. | Top of Page | Black KnotBlack knot affects plum and sometimes cherry. It causes hard, black swellings up to 10 cm long on branches and small twigs, eventually girdling and killing the branches. TreatmentCultural control: Remove and burn all knots when pruning or as soon as noticed, since early pruning will minimize spread. Make the cut at least 10 cm below the knot. Destroy nearby wild or neglected plum and cherry trees. Chemical control: Spray when leaf buds start to break. For up to date recommendations on pest management options consult local horticulturalists, Master Gardeners or your local garden supply centres. | Top of Page | Related Links| Top of Page | For more information:Toll Free: 1-877-424-1300 Local: (519) 826-4047 E-mail: ag.info.omafra@ontario.ca |
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