The patches extend and cover the whole leaf. Crop rotation, proper drainage and tuber treatment with0. The fungus is externally seed-borne and soil-borne. Sow the crop early in the season June sowing. Mode of Spread and Survival: The conidia are spread by air. Pythium irregulare Buisman; Pythium fabae G. On the leaves similar spots appear on the under surface.
Mode of Spread and Survival: The pathogen survives as oospores in the soil. Mode of Spread and Survival: The pathogen survives as uredospores on groundnut plant. Galls contain up to 80 adults in a 1:1 sex ratio. The insects mainly help in the spread of the disease. Mode of Spread and Survival: The pathogen survives in the dead leaves as dormant mycelium. The disease can be controlled by painting wounds with copper paints and drenching the area around the trees with fungicides like mancozeb or metalaxyl.
Rust: Puccinia sorghi Symptoms: Circular to oval, elongated, brown powdery pustules are scattered over both surface of the leaves. In severe cases, the infection may be seen on the flowers and young capsules, leading to premature shedding. Plant Nematodes: Their Bionomics and Control. Paxton Gornostai; Bipolaris multiformis Jooste Alcorn; Cochliobolus sativus S. Water shoots should be pruned to reduce infection. These include the reddening of the internal tissues which are usually elongated at right angles to the long axis of the stalk.
Detop in the third of forth week of December, 4. Cook Fusarium cerealis Cooke Sacc. During flowering period January-March , the conducive environmental conditions activate the dormant mycelium in necrotic leaves. Philosophical Transactions of the Royal Society of London 42:634-641. On the leaves, the lesions start as small water soaked bluish green flecks, soon enlarge and form characteristic spindle shaped spots with grey centre and dark brown margin. The disease is usually found when the plants are about 6 weeks old.
Mode of Spread and Survival: The fungus remains dormant as sclerotia for a long period in the soil and in infected plant debris. Favourable Conditions: Temperature of 25-30 °C with relative humidity above 80 per cent are highly favourable. Seeds free from nematode galls should be sown in nematode free drained field. Mode of Spread and Survival: The fungus overwinters in the form of mycelium in diseased vegetative buds and fruits. Pascher; Olpidium borzii De Wild.
The primary infection is mainly from infected setts. It colonizes the galled tissue stimulated by the nematode, and out-competes the nematode for this resource. Use optimum dose of fertilizers. Green steaks appear on the secondary veins under side of the lamena, 3. It is gram negative, non-spore forming. Early field symptoms of yellow ear rot or tundu disease consist of parallel yellow or white streaks along leaf veins. Vectors management by insecticides, 4.
Head rot : Rhizopus sp. Stunt nematodes: Geocenamus brevidens Allen Brzeski syns. Secondary spread is through air-borne conidia. It is transmitted in a persistent manner. Pathogen: The fungus produces usually long cells of septate mycelium which are hyaline when young, yellowish brown when old. Sprague Arx Black head molds Sooty molds a Alternaria alternata Fr.
In which disease of plant stem rot at soil line with brown to red lesions? Mixed cropping with suitable crops. Numerous spots occur on the young shoots. Rogue out weeds at periodical intervals. The lesions enlarge both in length and width with a wavy margin and turn straw yellow within a few days, covering the entire leaf. Leaves remain thin, narrow, reduced.