Paddy blast (Karpa):

Of Paddy.

This disease is first manifested on leaves as small spindleshaped brown spots with white centres. These spots grow in size and coalesce with each other. If the attack is at the time of emergence of the earheads, the necks are rotten and turned black. Such heads may not develop grains. If the attack is after the formation of grains, the necks do not support the weight of the panicles. The disease is prevalent on seedlings during July and August and on grown up crops during September-November.

The controlling measures include: (1) spraying of Bordeaux mixture 3:3:50 or any copper compound containing 50% metallic copper, (2) seed treatment with organo mercuria, and (3) dipping the seedlings in Bordeaux mixture before transplanting.

Bacterial Blight of paddy (karpa or kad karpa):

Some water soaked streaks and yellow bacterial ooze arc seen at the margins. The disease is prevalent during August and September. The disease can be controlled by destroying the debris of the plants after harvest and also by spraying the mixture of endrin 0.02% and copper oxychloride 0.3% three times at an interval of 20 days.

Black stem rust (tambera):

Of Wheat.

The disease appears as reddish brown elongated linear eruptive spots known as pustules mostly on stem and also on leaves, leaf sheath and awns in early part of the season. When the pustules are rubbed by thumb, a brownish powder smears on the surface of the thumb. This reddish brown powder contains spores called uredospores. Later on the endophytoc mycelium gives second type of black coloured sori or black pustules at the same erupted spot or side by side. The black pustules contain blackish powder consisting of spores called telentospores, or last spores. The disease occurs from November to February. Resistant varieties viz., Kenphad - 25, MED - 345, KCN, Hy - 65, NI - 917, Nl - 315, NI - 146, NI - 284 - 5, NI - 28, NI - 62, for irrigated crops and selection 59, and 125 for dry crops can be  grown to control the disease.

Loose smut (kani and kajali):

The rachis and awns are affected and loose blackish powder is formed in place of grains. The blackish powder consists of spores of the fungus. The disease is prevalent from January to March. The following special method has been evolved to control the disease effectively.

Soak the seed in cold water from 8 to 12 a.m. during the first fortnight of May, then spread the seed on galvanised iron sheets in hot sun for four hours and stir the seed periodically. Subsequently dry the seed in shade. After the drying, treat the seed with insecticides like D. D. T. and B. H. C.


of Groundnut.

Some conspicuous round purplish brown spots appear on the small plants. The spots later on increase in size and become blackish in colour. The spots caused by cercospora arachidicola are irregular, circular, black often confluent, varying in size from 1 mm. to 1 cm. in diameter and surrounded by a yellowish zone, blending into green. While the spots caused by cercospora personata are more or less circular, varying in size from 1 mm. to 7 mm. dark brown to black in colour and the lower surface of the spots marked with concentric stromatic rings of conidiophores. The spots are surrounded by a bright yellow halo. The disease occurs from August to October.

The disease can be effectively controlled by spraying the crop in the third week of July with 3: 3: 50 Bordeaux mixture or any copper fungicide containing 50% metallic copper. A second spraying in the month of August and a third one in the third week of September give good results. Dusting with 200-300 mesh sulphur @ 15-20 lbs. per acre can also control the disease.