Peach Diseases A
Lecture To ToT trainees ( FFS)
By Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan
Peach Brown Rot
Symptoms Brown rot on fruit Brown rot, caused by the
fungus Monilinia fructicola, causes the fruit to rot away while still on the tree. In its last stages the fruit is entirely brown and looks whithered and dried out. The fungus can live in many temperatures and climates, but it particularly loves moist climates. The rot can also turn flowers brown and cause new twigs to die off.
To prevent the spread, make sure to clear away affected fruit, twigs or flowers. Do not compost the remains, as the fungus spores can live in compost and spread to the rest of your garden. A fungicide can also stop the spread of the fungus. Good air circulation and a drier enviornment also helps prevent rot.
Peach Brown Rot
Symptoms of brown rot on peach blossom
Symptoms of brown rot on peach twigs and blossoms
Peach Brown Rot
Symptoms of brown rot on fruits Brown rot on fruit
Peach ScabCladosporium carpophilum
Symptoms Scab on peach fruit Peach scab is caused by a fungus
called Cladosporium carpophilu. It is most often found in warm, moist and humid areas, such as in the South. However, it can affect peach trees worldwide. The fruit will often crack and rot within those cracks, without much affect to the taste of the fruit. However, scab makes it harder for the peach skins to slip off during the canning process.
To prevent scab, use a chemical or organic fungicide just as the blossoms fall of the trees and for the ensuing month. Pruning and cleaning up fallen fruit and leaves will also prevent the continued spread.
Peach Scab
Scab symptoms on peach twigs Scab symptoms on peach fruit
Peach Scab
Scab symptoms on peach fruit Scab symptoms on peach fruit
Peach Powdery Mildew
Symptoms Powdery Mildew is caused by
the fungus called Sphaerotheca pannosa and affects both garden plants and fruit trees. Leaves often fall off or develop abnormally, eventually growing a white fuzz. An entire harvest can be ruined by mildew if left unattended. Consider purchasing tree varieties that aren't susceptible to the disease. Fungicide and proper area maintenance are also good preventative practices.
Peach Leaf Curl
Symptoms Leaf curl on peach
Leaf curl is a fungal disease caused by Traphrina deofrmans. It causes defoliation and crop loss in practically every variety of peach tree. Fungicide application during the fall after most of the leaves have fallen or before budding in spring can stop the fungus.
Leaf curl
Peach leaf infected with leaf curl Peach leaf curl symptoms
Peach Leaf Curl
Peach leaf curl symptoms on young peach tree
Peach leaf curl symptoms on foliage
Peach Leaf curl
Peach leaf curl symptoms Peach leaf curl symptoms
Peach Bacterial cankerPseudomonas syringae
Symptoms Canker on peach trunk 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
Cause Bacterium Comments Disease emergence favors high moisture and low
temperatures in the spring; young trees particularly susceptible; trees grown in sandy soils that drain poorly are also susceptible
Management Ensure that a suitable peach variety and rootstock
is chosen based on geographic location and environmental conditions to prevent stress to tree which predisposes tree to canker disease; apply protective copper spray to trees before flowering; prune trees in early summer to decrease likelihood of infection
Peach canker
Canker exuding gum on infected peach tree
Peach tree with dark cankers on bark
Canker on peach trunk
Canker on peach trunk Canker on peach trunk (bark peeled to show discoloration to tissue underneath)
Bacterial spot Xanthomonas campestris
Symptoms Peach tree infected with bacterial spot
Water soaked, angular gray lesions on the underside of the leaves which turn purple and necrotic in the center and cause a shot hole appearance if lesion center drops out; if lesions are present in high numbers on leaves they may become chlorotic and drop from tree; cankers develop on twigs either as raised blisters or as a dark area surrounding a bud that fails to open; in years of severe infection the entire fruit crop may be lost; lesions on fruit begin as small brown, water-soaked lesions which may exude gum
Cause Bacterium
Comments Periods of frequent rainfall during late bloom and early
petal drop increase likelihood of fruit and leaf infection; infection is rare during hot, dry weather
Management Avoid planting susceptible peach varieties in areas where
disease is known; once disease is visible it can be difficult to control, protective copper applications in the Fall prior to leaf drop and/or application in early growing season may help prevent the disease; care should be taken as peach trees are very sensitive to copper
Peach Bacterial Spot
Symptoms of bacterial spot on peach leaves
Symptoms of bacterial spot on peach leaves
Peach Bacterial Spot
Symptoms of bacterial spot on peach leaf
Symptoms of bacterial spot on peach fruit
Peach Crown gallAgrobacterium spp
Symptoms Large gall on trunk of peach tree Galls on roots 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
Cause Bacterium Comments Infection with crown gall begins at the site of plant
wounds; disease emergence is favored by poorly-drained, alkaline soils and previous feeding damage by nematodes
Management Chemical control of the disease is generally
ineffective; an effective bacterial biological control is available for commercial production; cultural control methods include: planting only certified, disease-free material, planting peach in well-draining soil, rotating infected fields with a non-host before peach is planted and also using good sanitation practices
Crown Gall
Symptoms of crown gall on trunk of peach tree Galls on roots of peach tree
Crown Gall
Crowm gall symptoms Symptoms of crown gall on trunk of peach tree
Crown Gall
Gall on peach tree Galls on peach roots
Peach Shot hole diseaseWilsonomyces carpophilus
Symptoms Shot hole lesions on peach fruit
Brown lesions with purple edge on fruit, twigs and buds; holes in leaves due to lesions which have dried and dropped out; brown lumps developing in the center of lesion (visible with hand lens); buds turning brown or black and exuding sap; tan lesions with brown margins which exude sap on twigs
Cause Fungus Comments Disease emergence favors wet, windy
conditions Management Application of Bordeaux mixture before
rains in Fall are sufficient to protect dormant buds and twigs over winter
Shot Hole
Shot hiole symptoms on peach fruit
Shot hole lesions on peach fruit
Peach Silver leaf diseaseChondrosterum 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
Cause Fungus Comments Pathogen is spread via spores released after
rainfall during periods of high humidity and can enter trees through pruning wounds; risk of infection is increased if tree is pruned during late winter or early spring; trees also susceptible when they are heavily pruned
Management Control of silver leaf disease is difficult and
infection can be widespread after rainfall in areas where the disease is present; strategies to reduce the incidence of the disease include: removing all plant debris e.g. pruning waste, stumps, and logs; pruning tree during dry periods and treating large pruning wounds with fungicidal dressing
Phytophthora root and crown rotPhytophthora spp.
Peach tree showing symptoms of Phytophthora infection
Peach RustTranzschelia discolor
Symptoms Rust spots on peach leaves 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
Cause Fungus Comments Fungus overwinters in twigs or in leaves
which remain attached to the tree Management Rust can be prevented by spraying trees
with protective fungicides; application is usually carried out one, two and three months before harvest in areas prone to early season outbreaks of the disease and after harvest in areas where disease is less problematic or emerges later in the season
Peach Rust
Rust symptoms on peach leaves Rust symptoms on peach leaves
Plum pox virusPlum pox virus (PPV)
Symptoms Symptoms of plum pox on peach fruit
First expanding leaves exhibit chlorotic veinclearing and veinbanding; lamina twisted and distorted; fruit show dark rings, lines and spots; symptoms on fruti may disappear on ripening; fruit may be deformed
Cause Virus Comments Virus is transmitted by aphids but most
common method of spread is diseased plant material
Management Plant certified healthy material; remove
infected trees from orchard; chemical sprays to control aphids may prolong spread of virus
Peach Fruittree leafrollerArchips argyrospila
Symptoms Fruittree leafroller Leaves of plant rolled and tied together with
silk webbing; feeding damage to rolled leaves; defoliation of plant; silk webbing may also be present on fruits and fruits may have substantial scarring from feeding damage; larvae wriggle vigorously when disturbed and may drop from plant on a silken thread
Cause Insect Comments Only one generation of insect per year Management Monitor plants regularly for signs of infestation;
remove weeds from plant bases as they can act as hosts for leafrollers; avoid planting pepper in areas where sugarbeet or alfalfa are grown nearby; Bacillus thuringiensis or Entrust SC may be applied to control insects on organically grown plants; apply sprays carefully to ensure that treatment reaches inside rolled leaves