Groundnut or peanut – Arachis hypogea
Tikka disease of groundnut
Pathogen Disease incited by a fungus Cercospora personata.
Systematic position The fungus belongs to class Deuteromycetes.
Lesions appear on the leaves, when the plants are atleast two months old. The symptoms appear in July and continue upto maturity of the plant.
The lesions on the leaves are rounded and 1 to 6 mm in diameter. These spots are dark brown or black and found on both surfaces of the leaf. Yellow border develops around each such leaf spot.
The mycelium of Cercospora personata is brown, septate branched
and slender. Branched haustoria are produced to absorb food materials from the host tissue.
The conidia are long and septate. Each conidiophore produces single conidium at its tip. The spread of the disease takes place by means of conidia which are dispersed by wind.
The disease can be controlled by sanitation and crop rotation. The
use of phosphatic and potassic manures reduce the disease. Sulphur dusting is quite effective. Resistant variety should be sown.