A mycoparasite on Sclerospora graminicola

Downy mildew or 'green ear' disease of pearl millet (Pennisetum typhoides Stapf and Hubb.) incited by Sclerospora graminicola (Sacc.) Schröter has become a major disease on several improved varieties of the crop plant in India. Fusarium semitectum Berk, and Rav. parasitizes the oospores that develop within the leafy proliferations in the earhead, which consequently makes them unviable. The possibility of using the mycoparasite as a biological control is indicated.

Conidial release in Pyricularia penniseti

Conidiophores and conidia of <i>Pyricularia penniseti </i>Prasada and Goyal undergo violent hygroscopic movements when transferred from humid to dry atmosphere. The conidia are detached and dispersed forcibly from the conidiophores as a result of these movements. Although the conidia are not projected to long distances, the forcible detachment facilitates further removal by air currents to hasten secondary infection of the younger host leaves in succession.

Conidial discharge in Protomycopsis thirumalacharii

Mechanism and occurrence of conidial discharge in <i>Protomycopsis thirumalacharii </i>Pavgi, causing the purple leaf spot of <i>Sesbania grandiflora </i>Pers. was studied in detail. The conidia were ‘shot off’ violently from the conidiophores only in dry atmosphere at a temperature range of 15-30°C. Field observations also corroborated the mode of pathogenic infection on the host leaves.