Cherry Diseases A

Lecture To ToT trainees ( FFS)

By Mr. Allah Dad Khan

Provincial Coordinator IPM KPK

MINFAL Pakistan

Crown and root rotPhytophthora spp.Symptoms

Poor new growth; leaves chlorotic, small in size and sparse; fruit may be small, brightly colored and susceptible to sunburn; shoots may suffer from dieback and tree will often die within weeks or months of first signs of infection or decline gradually over several seasons; root crown may show signs of decay which develops into a canker; bark of infected crown tissue turns dark brown; cankers may occur on aerial parts of plan

Powdery mildew Podosphaera spp.

Symptoms

Light colored circular lesions on leaves inside tree canopy which develop a powdery appearance; lesions may coalesce to cover leaf; if infection is severe, leaves may blister and infected shoots may be distorted and stunted; infected fruits may have slightly depressed areas on the surface containing fungal hyphae (filamentous fungal structures)

Silver leaf Chondrosterum pupureum

Symptoms

Leaves have a silvery appearance; if infection is severe the leaves may curl upwards and become necrotic; death of individual limbs or entire tree may occur; fungal fruiting bodies appear on the surface of the dead bark

Bacterial cankerPseudomonas syringae

Symptoms

Cankers on twigs at bases of flower and leaf buds, in pruning wounds or at the base of spurs which exude amber colored gum; cankers spread upwards and form sunken areas in winter; if pathogen enters dormant buds they may be killed or open normally in Spring before collapsing in early Summer; infected buds may be symptomless

Crown gallAgrobacterium spp

Symptoms

Galls on root and/or crown of tree which can range in size from so small they are not visible to the naked eye up to 10 cm (4 in) in diameter; galls first become visible as white, fleshy swellings that grow rapidly and become tan to brown in color; galls typically develop at the site of a wound and new galls form adjacent to old ones the next year

X-diseaseX-disease mycoplasma-like organism (MLO)

Delayed fruit maturity caused by X-disease

Symptoms

Rapid or slow decline of tree depending on rootstock; in hypersensitive rootstocks such as Prunus mahaleb cherry scion is rapidly girdled; cherry grafted on susceptible rootstocks exhibit a slow decline over a number of years; leaves on infected limbs are small with a red tinge; fruit may mature late and color development may be incomplete; limbs experience dieback and the tree is killed

Cherry leaf spotCoccomyces hiemalis

Symptoms Cherry leaf spot lesions on sweet cherry leaf

Small, red-purple spots on upper surfaces of leaves which turn brown and may coalesce; leaves may become chlorotic if there are a few lesions present; if tree becomes severely defoliated fruit may fail to develop properly and remain light in color and watery in texture

Black knotApiosporina morbosaSymptoms Black knot on black cherry

stem

Elongated swellings (knots) on woody parts of tree which can reach up to 30 cm (12 in) long; knots are initially olive green in color with a corky texture but turn black in color and become hard and brittle; knots grow in length each year

Black knotBlack knot symptoms on cherry

Black knot symptoms on cherry

Brown rotMonilinia fructicola

Symptoms Cherry fruits infected with brown rot fungus

Brown discoloration of fruit skin and inner tissue; fruit skin wrinkled; collapsed flowers exuding sap from their bases; tan cankers with dark edges on twigs; gray-brown spore masses may be present on cankers

Cherry rasp leafCherry rasp leaf virus (CRLV)

Symptoms Cherry leaves infected with cherry rasp leaf

Leaf like growths (enations) on underside of leaves near center; symptoms spread from lower parts of tree upwards; defoliation of limbs; decline of tree

Sour cherry yellowsPrune dwarf virus (PDV)

Symptoms

Chlorotic rings or mottled pattern on newly expanded leaves of sour cherry which become necrotic and may drop out of leaves, giving them a shot hole appearance; leaves that expand after the initial symptoms have become visible display lesser and lesser symptoms; one or more years later leaves on infected trees become yellow with green mottle and drop from tree; fruit yield may be reduced by up to 50%; sweet cherry trees develop chlorotic spots or rings with some shot holes; fruiting spurs decrease in later years as the disease progresses; fruit on infected trees are generally firmer and larger than on uninfected

Verticillium wiltVerticillium dahliae

Symptoms Symptoms of Verticillium wilt on sweet cherry tree

Withering of leaves on one or more spurs on 1 year old wood; leaves are dull and stunted; fruit small; older cherry trees do not recover from disease

RustTranzschelia discolor

Symptoms

Pale yellow-green spots on both upper and lower leaf surfaces which are angular in shape and turn bright yellow in color; spots on lower leaf surface develop orange-red spores