avacado diseases by allah dad khan provincial coordinator ipm kpk minfal
TRANSCRIPT
AvacadoDiseases A
Lecture To ToT trainees ( FFS)
By Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan
Anthracnose symptoms Anthracnose symptoms
AnthracnoseGlomerella cingulata
Anthracnose symptoms Anthracnose symptoms
Anthracnose
Anthracnose symptoms Anthracnose symptoms
Anthracnose
Symptoms
Chlorotic and necrotic spots; dead leaf tip; defoliation; brown or purple lesions on new shoots
Cause Fungus Comments Spores spread by rain splash; high
moisture and warm temperatures encourage spread
Management Prune dead twigs and branches from
tree before fungi produce spores; knock dead leaves out of canopy; keep harvested fruit dry and cool
Chloratic Disease
Avocado scab Scab symptoms
Scab Sphaceloma perseae
Symptoms
Oval or irregular brown or purple spots on fruit with rough texture
Cause Fungus Comments High humidity encourages scab
growth and spread Management Plant tolerant varieties; spray
with copper containing fungicides
Purple Spot
Symptoms
Elongated black streaks on bark; cankers parallel to growth of limbs; black blotches with distinct margins on green wood; cankers on bark cause cracks which ooze sap; removal of bark over cankers reveals dark discoloration underneath
Cause Unknown Comments Disease emergence favors adverse
growing conditions for avocado; more common in Guatemalan cultivars
Management Avoid stressing trees by following good
fertilization and irrigation practices
Black streak Avocado black streak
Symptoms
Black lesions on roots; black, brittle roots; small, yellow leaves; premature leaf drop; decline in fruit yield
Cause Oomycete Comments Wet soils encourage Phytophthora
infection; plant in a well draining soil.
Management Minimize water splash between trees
by not working in a wet orchard; prune out dead limbs and twigs; remove fruit from the ground; dispose of dead wood and fruit away from trees
Phytophthora root rot and crown rot Phytophthora cinnamomi
Fruit symptoms of P. citricola
Tree trunk with symptoms of Phytophthora citricola.
Phytophthora
Symptoms
Shrivelled tissue at stem end; dark brown or black lesions at stem end and eventually over entire fruit; fruit covered in mycelium
Cause Fungi Comments Environmental conditions may determine
which fungal species is most common; spores can spread by wind or rain.
Management Prune dead limbs and twigs; prune and
harvest in dry conditions; provide trees with sufficient irrigation; apply a thick layer of mulch
Stem-end rot
Symptoms
Symptoms Gray to black, mushy, foul smelling rot on
fruit; fruti has darkened metallic sheen
Cause Bacteria Comments Bacteria may be present on leaves but do not
cause damage unless plant is stressed or bacteria enter the plant through a wound
Management No treatment for disease; use certified seed;
disinfected tools and cuttings; employ crop rotation; remove plant debris from soil
Bacterial soft rot
Symptoms
Red, yellow, pink or white streaks running the length of young stems; white, yellow or red blotches on fruit
Cause Viroid Comments Can be transmitted by grafting Management Frequently sanitize all pruning
equipment with disinfectant; plant only certified nursery stock
SunblotchAvocado sunblotch viroid (ASBVd)
Algal leaf spot symptoms Algal leaf spot symptoms
Algal leaf spotCephaleuros virescens
Symptoms Algal leaf spot symptoms
Raised, orange-red spots on both upper and lower surfaces of leaves; spots may coalesce to form irregularly shaped patches; spots may also be present on twigs and branches; when the surface of the spot is scraped away, a gray to dark necrotic crust is visible
Algal Leaf Spot