Damping off: Pythium aphanidermatum
- The populations in nursery seedlings die due to this diseases
- Mycelium are hyaline and Aseptate and its has width size 5 micron
- Irregular mycelial fibers grown and thus produce irregular shape spores
- Seedlings killed before emergence
- Water soaking and shrivelling of stem
- Factors favouring infection:Moist soils poordrainage 90-100% R.H soil temperature 20°C
- Impact of disease symptoms shown at after sowing of seeds in seed beds
- It will reduce the seed germination percentage
- its affects the young seedlings and their stems
- lodging of seedlings due to weaken stems
- disease affected seedling are seen light brownish colour
- diseases spread through seeds and soil.
- Soil drenching with Copper oxychloride 0.25%
- avoid shade places for nursery establishment
- use recommended seed rate
- avoid flooding type of irrigation and maintain optimum moisture level in nursery
- use Thiram or Capton @ 4g/ kg of seeds for seed rate
Fruit Rot and Die Back: Colletotrichum capsici
|Symptoms As the fungus causes necrosis of tender twigs from the tip backwards the disease is called die-back Infection usually begins when the crop is in flower. Flowers drop and dry up. There is profuse shedding of flowers. The flower stalk shrivel and dry up. This drying up spreads from the flower stalks to the stem and subsequently causes die-back of the branches and stem and the branches wither. Partia1lly affected plants bear fruits which are few and of low quality. On the surface of the soil the necrotic areas are found separated from the healthy area by a dark brown to black band.|
- Use of disease-free seeds is important in preventing the disease. Seed treatment with Thiram or Captan 4g/kg is found to be -effective in eliminating the seed-borne inoculum.
- Good control of the disease has been reported by three sprayings with Ziram O. 25% Captan 0.2% or miltox 0.2%. Chemicals like wettable sulphur 0.2%, copper oxychloride 0.25% and Zineb 0.15% not only reduced the disease incidence but also increased the yield of fruits.
- The first spraying should be given just before flowering and the second at the time of fruit formation.
Third spraying may be given a fortnight after second spraying
Powdery mildew: Leveillula taurica
- Shedding of foliage
- white powdery growth on lower side of leaves
|Management Spray Wettable sulphur 0.25% or Dinocap (Karathane) 0.05% |
Fusarium wilt: Fusarium oxysporum f.sp.capsici Symptoms Fusarium wilt is characterised by wilting of the plant and upward and inward rolling of the leaves. The leaves turn yellow and die. Generally appear localised areas of the field where a high percentage of the plants wilt and die, although scattered wilted plants may also occur. Disease symptoms are characterised by an initial slight yellowing of the foliage and wilting of the upper leaves that progress in a few days into a permanent wilt with the leaves still attached. By the time above – ground symptoms are evident, the vascular system of the plant is discoloured, particularly in the lower stem and roots. Management Use of wilt resistant varieties. Drenching with 1% Bordeaux mixture or Blue copper or Fytolan 0.25% may give protection.· Seed treatment with 4g Trichoderma viride formulation or 2g Carbendazim per kg seed is effective. Mix 2kg T.viride formulation mixed with 50kg FYM, sprinkle water and cover with a thin polythene sheet. When mycelia growth is visible on the heap after 15 days, apply the mixture in rows of chilli in an area of one acre.
Viral diseases Leaf curl Leaves curl towards midrib and become deformed. Stunted plant growth due to shortened internodes and leaves greatly reduced in size. Flower buds abcise before attaining full size and anthers do not contain pollen grains. The virus is generally transmitted by whitefly. So control measures of whitefly in this regard would be helpful. Mosaic Viruses Light green and dark green patches on the leaves. Stunted plant growth during early stages. Yellowing, chlorotic ring spots on leaves and fruits. Management of viral diseases Control measures are not known for majority of viral diseases. Hence, mechanical, cultural methods are mostly recommended. The infected plants should be uprooted and burnt or buried to avoid further infection. Avoid monoculture of chilli crop. Selection of healthy and disease – free seed. Suitable insecticidal sprays reduce the incidence of viral diseases, since majority of viral diseases are transmitted by insect vectors. Soaking seeds in a solution containing 150 g Trisodium orthriphosphate per litre of water for 30 minutes inhibits seed – borne inoculum. Treated seed should be washed with fresh water and dried before sowing. Nursery beds should be covered with nylon net or straw to protect the seedlings from viral infection. Raise 2-3 rows of maize or sorghum as border crop to restrict the spread of aphid vectors. Apply Carbofuran 3G @ 4-5 Kg/acre in the mainfield to control sucking complex and insect vectors selectively. If it is not possible spray the crop with systemic insecticides. Dimethoate 2ml of Acephate 1g per litre of water. Collect and destroy infected virus plants as soon as they are noticed.
Pest management in chilly Chilli thrips: Scirtothrips dorsalis Symptoms of damage: The infested leaves develop crinkles and curl upwards Elongated petiole Buds become brittle and drop down Early stage, infestation leads to stunted growth and flower production, fruit set are arrested Identification of pest: Nymph: Are small, linear, easily fragile abdomen with straw yellow colour Adult: Fringed wings Management: Inter crop with agathi (Sesbania grandiflora) to provide shade which regulate the thrips population Do not grow chilli after sorghum Do not follow chilli and onion mixed crop Sprinkle water over the seedlings to check the multiplication of thrips Treat seeds with imidacloprid 70% WS @ 12 g/kg of seed Apply carbofuran 3% G @ 33 kg/ha or phorate 10 % G @ 10 kg/ha or Spray any one of the following insecticide Insecticide Dose Imidacloprid 17.8 % SL 3.0 ml/10 lit. Dimethoate 30 % EC 1.0 ml/lit. Emamectin benzoate 5 % SG 4 g/10 lit. Ethion 50 % EC 2.0 ml/lit. Fipronil 5 % SC 1.5 ml/lit. Oxydemeton –Methyl 25 % EC 1.0 ml/lit. Phosalone 35 % EC 2.0 ml/lit. Spinosad 45 % SC 3.2 ml/10 lit. Thiacloprid 21.7 % SC 6.0 ml/10 lit. Green peach aphid: Myzus persicae Symptoms of damage: The infested plants turn pale with sticky appearance The leaves curled and crinkled Honeydew excrete – development of sooty mould Stunted growth of the plant Identification of pest: Nymphs: Initially are greenish, but soon turn yellowish Adults: yellowish green in colour Management: Treat seeds with imidacloprid 70% WS @12 g/kg of seed Apply phorate 10 % G @10 kg/ha Spray any one of the following Insecticide
Insecticide Dose Carbosulfan 25 % EC 1.0 ml/lit. Fipronil 5 % SC 1.0 ml/lit. Imidacloprid 17.8 % SL 3.5 ml/10 lit. Oxydemeton –Methyl 25% EC 1.6 ml/lit. Phosalone 35 % EC 2.0 ml/lit. Quinalphos 25 % EC 1.0 ml/lit. Yellow mite or muranai mite: Polyphagotarsonemus latus Symptoms of damage: Downward curling and crinkling of leaves Leaves with elongated petiole Stunted growth Identification of pest: Egg: Oval shaped eggs and white in colour Nymphs: white in colour Adult: Large, oval and broad and yellowish in colour Management: Encourage the activity of predatory mite: Amblyseius ovalis Apply phorate 10 % G @10 kg/ha or spray any one of the following insecticide Insecticide Dose Buprofezin 25 % SC 8.0 ml/10 lit. Chlorfenapyr 10 % SC 1.5 ml/lit. Diafenthiuron 50 % WP 8.0 g/10 lit. Dimethoate 30 % EC 1.0 ml/lit. Ethion 50 % EC 2.0 ml/lit. Fenazaquin 10 % EC 2.0 ml/lit. Fenpyroximate 5 % EC 1.0 ml/lit. Hexythiazox 5.45 % EC 8.0 ml/10 lit. Milbemectin 1 % EC 6.5 ml/10 lit. Oxydemeton –Methyl 25 % EC 2.0 ml/lit. Phosalone 35 % EC 1.3 ml/lit. Propargite 57 % EC 2.5 ml/lit. Quinalphos 25 % EC 1.5 ml/lit. Spiromesifen 22.9 % SC 5.0 ml/10 lit. Gram caterpillar: Helicoverpa armigera Symptoms of damage: Early instar feeds on foliage Grown up larvae mainly bore into the fruits. Identification of pest: Eggs: Are spherical in shape and creamy white in colour, laid singly Larva: Shows colour variation from greenish to brown Pupa: Brown in colour, occurs in soil, leaf, pod and crop debris Adult: Female is brownish yellow stout moth, Male is light greenish in colour with “V” shaped markings. Management: Collect and destroy the infected fruits and grown up larvae Setup pheromone trap with Helilure at 15/ha Six releases of Trichogramma chilonis @50,000/ha per week coinciding with flowering time Release Chrysoperla carnea at weekly interval at 50,000 eggs or grubs / ha from 30 DAS. Spray HaNPV at 1.5×1012 POB/ha along with cotton seed oil 300 g/ha to kill larvae. Spray carbaryl 50 WP 2 g/lit or B. thuringiensis 2 g/lit Provide poison bait with carbaryl 1.25 kg, rice bran 12.5 kg, jaggery 1.25 kg and water 7.5 lit/ha or spray any one of the following insecticide Spray any one of the following insecticides
Insecticide Dose Emamectin benzoate 5 % SG 4 g/10 lit. Flubendiamide 20 WDG 6.0 g /10 lit. Indoxacarb 14.5 % SC 6.5 ml/10 lit. Novaluron 10 % EC 7.5 ml/10 lit. Spinosad 45 % SC 3.2 ml/10 lit. Thiodicarb 75 % WP 2.0 g/lit.