Pests & Diseases

SARDI Home

 

Stone Fruit Pests & Diseases

 

Disease Crops Affected Symptoms
Bacterial canker
Apricots and plums especially, but all stone fruit susceptible

Limbs or whole trees collapse and die (usually in first or second year after planting).

Cankers often exude large amounts of gum, vinegar (sour) smelling. Brown or tan discolouration in the bark (orange in the case of apricots). Outer layers of wood often stained a brown colour.

Water soaked spots on leaves, becoming dry and brittle and falling out of the leaf giving it a shothole appearance.

Fruit develop depressed spots with dark centres, sometimes with underlying gum pockets. 

Black heart Apricot worst affected, has been reported on other stone fruit Slow defoliation, leaves wilt slightly, turn yellow then fall. Fruit sets but fails to develop.
Blossom and twig blight All stone fruit Twigs ooze gum near areas of dead or dying bark. Kills blossoms and twigs.
Brown rot Mainly peaches, necatrines and apricots, other stone fruit can be affected

Blossoms turn brown and die. Twigs ooze gum near areas of dead or dying bark.

Small brown spot on maturing fruit, quickly enlarges to large firm brown patch.

Bryobia mite Pears, to a lesser extent stone fruit Whitish grey spots on leaves resulting in a stippled appearance when leaves grow. Discoloured leaves which fail to grow.
Crown gall Most common in peaches, but all stone fruit can be affected Galls on crowns of root system (at base of trunk). Initially galls are creamy coloured and soft, become darker and woody as they grow. Tops of severely affected trees weak and stunted, leaves pale in colour, tinted with red.
Eutypa dieback (formerly Gummosis) Apricots

Rapid wilting of leaves, dead leaves remain attached to tree. Fruit often remains small, ripens before fruit on healthy branches.

Infected areas on branches become brown and dry.

Freckle Apricots and peaches, but affects all stone fruit

Small circular patches on fruit, enlarge and become scabby. On apricots patches pale green at first, later darkening. On peaches patches raised and black. On nectarines patches pale green with dark centre.

Grey spots on leaves and tattered edges. Branches stunted, die at tips.

Frosted plum scale
Plums and apricots, sometimes peaches and nectarines Black sooty mould growth on the underside of leaves.
Green peach aphid Peaches and nectarines

Foliage damage appears as soon as leaves emerge from buds. Leaves turn yellow, shrivel and fall. In severe infestations, shoots are killed.

Katydid Stone fruit, pome fruit to a lesser extent White to grey scar (caused by katydid bite) on the surface of fruit, expands as the fruit grows.
Leaf curl Mainly peaches and nectarines, occasionally apricots

Leaves thickened, curled and grossly deformed, changing colour to a lighter green, often with red to purple tints, then brown, withers and drops prematurely.

Shoots stunted.

Fruit develop raised and distorted blister-like areas with red to purple tints.

Light brown apple moth Pome fruit and apricots, other stone fruit can be infested Damage to fruit, usually confined to the surface, most common in lower half and central parts of the tree.
Oriental fruit moth Mainly peaches and nectarines, sometimes apricots Commonly infests ripening fruit leading to fruit rot.
Replant disorder All stone fruits Newly planted trees slow to establish, tree growth uneven, trees may die.
San Jose scale
Stone and pome fruit Abnormal yellowing of leaves, unseasonal leaf drop, gumming and cracking of the bark, followed by dieback of the infected branches. Tops of trees usually the first injured. Bright red discolouration often shows up on young wood, especially on peaches.
Shothole Apricots and other stone fruits

Leaves with small brown spots with reddish margins, spots dry and fall out of leaf. Premature defoliation of the tree. Twigs with irregular brown spots that ooze large amounts of gum.

Fruit with small circular, deep purple spots. On apricots spots become brown, raised and rough. On peaches and nectarines scabs develop into deep indentations. Fruit have spots of gum and can have cracks in the skin.

Silverleaf All stone fruits Leaves with pale grey metallic sheen. Brown discolouration of heartwood.
Stone fruit rust All stone fruits

Irregular pale yellow patches often running together on upper surface of leaves. Brown spots on underside of leaves, leave a rusty powder on fingers. Blotchy yellow leaves that drop prematurely.

Small dead patches on shoots, split bark.

Fruit with small green sunken spots with red centres, spots can join causing the skin to crack.

Two-spotted mite Stone and pome fruit Lightly infested leaves have pale spots which give the leaf a speckled appearance. More intense infestations cause bronzing or yellowing of the leaves which prematurely drop.
Virus Stone fruit Vary from no symptoms, leaf symptoms, and vigour, fruit size and yields reduced.
Yeast rots Most common on apricots, but affects all stone fruits When fruit is cut in half, flesh surrounding the stone cavity is watery, often with white smearing.