Epidemiological factors for Blast (Magnaporthe grisea) disease of Cumbu (Pennisetum glaucum) and Ragi (Eleusine coracana) in TamilNadu

Abstract

Nutricearals for Cumbu, Ragi, Kuthiraivali, Tenai, Samai and Varagu is most important small millets crops of TamilNadu, the biotic and abiotic stresses constitute the major yield destabilizing factors. The cumbu rust and blast of cumbu, ragi and tenai was observed to be widely distributed the entire Tuticorin district in the year 2022. cumbu rust diseases higher in Padarnthapuli village (30.52PDI) and blast disease for A.Lakshmipuram (16.65PDI), Ragi and Tenai leaf blast (12.21 and 7.70 PDI) incidence in High for Kovilpatti, there was no disease recorded in samai and varagu crop, In fixed plot survey A positive correlation was obtained between the incidence of cumbu rust and maximum temperature (r=0.92), Minimum temperature (r=0.99), in cumbu blast and maximum temperature (r=0.96), Minimum temperature (r=0.97), Relative humidity (r=0.78) positive correlations. For Ragi A positive correlation was obtained between the incidence of Ragi blast and maximum temperature (r=0.78), Minimum temperature (r=0.89), Negative correlation was obtained between incidence of blast and rust rainfall and wind speed.