Pests and Disease Management in Avocado

Pests and Disease Management in Avocado

Algal leaf spot Avocado thrips Bacterial Soft Rot Persa mites Phytophthora Root Rot Sunblotchs

Disease	Symptoms	Cause	Comments	Management
Anthracnose (Glomerella Cingulata)	Dead leaf tip, defoliation, brown or purple lesions and necrotic spots	Fungus	Spread by rain, high moisture and warm temperatures encourage spread	Prune dead twigs and branches from tree before fungi produce spores, remove dead leaves
Scab (Sphaceloma perseae)	Irregular brown or purple spots on fruit with rough texture	Fungus	High humidity encourages scab growth and spread	Spray copper containing fungicides
Stem-end rot	Shriveled tissue at stem end, black lesions at stem and eventually over entire fruit	Fungi	Environmental conditions, spores can spread by wind or rain	Prune dead limbs and twigs, prune and harvest in dry conditions, apply thick layer of mulch
Phytophthora Root Rot (Phytophthora cinnamom)	Black lesions on roots, black, brittle roots, small yellow leaves, decline in fruit yield	Oomycete	Wet soils encourage Phytopthora infection, plant in a well drainage soil	Prune out dead limbs and twigs, remove fruit from the ground, Minimize wet splash between trees
Bacterial soft rot (Erwinia herbicola Erwinia carotovora)	Gray to black, mushy, foul smelling rot on fruit	Bacteria	Bacteria may be present on leaves but do not cause damage unless plant is stressed or bacteria enter the plant through a wound	No treatment for disease, remove plant debris from soil, use certified seed
Sunblotchs (Avocado sunblotch virodi – ASBV)	Red, yellow, pink or white streaks running the length of young stems	Viroid	Can be transmitted by grafting	Sanitize all pruning equipment with disinfectant
Western Avocado Leafroller ( Amorbia)	Defoliation of tree, scarred fruit, young larvae are yellow-green and mature to dark green and a short, dark horizontal line on the side of thorax	Insect	Female can lay between 150 to 200 eggs during her life time, insect generally undergoes 3 generations per year	Application of selective insecticide such as Bacillus thurengiensis help to conserve populations of natural enemies
Avocado thrips (Scritothrips perseae)	Feeding scars on fruit,adult insect is orange-yellow in color with distinct brown bands	Insect	Insect thrives in cooler temperature, insect may undergo 6 or more generations per year	Organic mulch about  6 inches thick below trees may help to reduce survival of thrips pupating  in soil, insecticide recommended to reduce damage to populations of natural enemies
Algal leaf spot (Cephaleuros virescens)	Orange red-spots on both upper and lower surfaces of leaves, spots may coalesce to form irregularly shaped patches	Alga	Disease affects many fruit trees in the tropics, infection is unsightly but often harmless	Ensure trees are properly pruned and fertilized to promote vigor, remove all weeds from around tree bases, badly infested trees can be treated with copper containing fungicides
Persea mites (Oligonychus perseae)	Defoliation, mites cause the development of circular chlorotic to brown spots on the undersides of the leaves and fruit surface	Arachnid	Persea mites are most damaging on Hass and Gwen varieties	Ensure the tree is adequately fertilized, pruned properly and irrigated to avoid unnecessary stress to the tree

See also :
Types of Animal Manures to Increase Organic Content
Pests and Disease Management in Banana
Pests and Disease Management in Lemon