To determine the susceptible age of stem rot disease caused by Sclerotium rolfsii Sacc. in groundnut

Abstract

An experiment was carried out in net house of Department of Plant Pathology, Junagadh Agricultural University, Junagadh, during Kharif -2017 under pot culture. Seven stages i.e., 0, 6, 12, 18, 24, 30, 36 days after sowing (DAS) of groundnut plants were selected for their susceptible reaction against stem rot causal pathogen S. rolfsii. Groundnut plants were inoculated 16, 22, 28, 34, 40, 46 and 52 days after last pot sowing (days) by actively mycelium and sclerotia developed on sorghum grains places near the stem of groundnut plants. Observations recorded after 7 days developed stem rot symptoms. Result revealed that, stem rot developed in all inoculated plants but severity decreased with increasing plant age at inoculation. Highest disease severity (73.33%) was recorded at 45 DAS inoculated plants. Our findings suggest that plants are more susceptible to infection at early development stages. However, susceptibility to stem infection was reduced after 45 DAS of inoculation. Moreover, young stage of maturity was more susceptible to S. rolfsii.