PresentWEFWEFWERWERWERWERREWREWation.pptx
- 1. DISEASES OF SAPOTA SUBMITTED BY ADMISSION NO.-221810002
- 2. DISEASES OF SAPOTA : 1.Phavophleospora leaf spot : Symptoms : ? Numerous,small, circular,pinkish to reddish brown,conspicuous spots with whitish center on mature leaves. ? Spots coalesce and leaves drop prematurely. Causal organism : Phavophleospora indica Mode of spread : ? The pathogen spreads through wind borne conidia. Mode of survival : ? Severe during oct-dec ? Fungus grows best at 25°C and 90% RH ? Susceptible varieties : Cricket ball,Kirthabarthi,Mimusops hexandra (root stock ) Management : ? Avoid suspectible varieties ? Spray zineb @0.2% or ziram@0.2% or COC @0.25%
- 3. DISEASES OF SAPOTA : 2. Pestalotiopsis leaf spot : ? Small, reddish brown specks on leaf lamina ? Spots enlarge,become circular measuring 1 to 3 mm in diameter ? Fully developed spots show grayish centre and dark brown to reddish margin ? Minute black fruiting bodies (pycnidia) are seen in the centre of spots Causal Organisms Pestalotiopsis versicolor Management : ? Spray zineb @0.2%
- 4. DISEASES OF SAPOTA : 3. Sooty Mould : ? Black superficial growth on entire surface of leaves, fruits and twigs. ? It is a fungal disease developed on honeydew like excretion secreted by aphids and scale insects ? The fungus slowly covers the entire leaf area severely affecting the process of photosynthesis. ? This results reduced translocation of food to the fruits, which leads to reduction in their size. Etiology : ? Capnodium versicolor ? Mycelium is sepate,dark coloured and superficial ? The fungus is associated with the infestation of scales and mealy bugs. Mode of spread : ? Primary source is dormant mycelial ? Secondary source is air borne conidia ? Spread by insects,aphids, wind Epidemiology : ? Temperature 28-32°C, 85-90 % RH,warm weather and susceptible host. Management : ? Spray of wettable sulphur 0.2% along with insecticide dimethoate 1.5g/lit ? Spray of 1? starch solution makes flakes of the fungus.
- 5. DISEASES OF SAPOTA : 4. Red rust : ? Initial green coloured, circular patches with marginal serrations. ? The upper surface of the spot consist of numerous, unbranded filaments, which project through cuticle. ? When disease advances the organism turns red rusty spots on the leaves and young twigs. ? Spores mature,fall off and leave cream to white velvet texture on the surface of leaf. Causal organism :Cephaleuros versicolor Epidemiology : ? Close plantation ? Zoospores cause initial infection ? High moist condition favours development of fruiting bodies of the algae. Management : ? It is controlled by spraying with Bordeaux mixture 1% or COC 0.3% or lime sulphur 0.2%
- 6. DISEASES OF SAPOTA : 5. Flat limb : ? Branches of affected trees become flat and twisted. ? Leaves become thin,small and yellow ? Cluster of leaves and flowers on affected twigs. ? Flowers remain infertile ? If fruits are set,they are undersized,hard and fail to ripen ? Foliage and fruits fall prematurely Causal organism : Botryodiplodia theobromae Management : ? Pruning of affected branches followed by Captan or Zineb 0.3% spray