Measuring and assessing the yield loss and yield loss model of green gram due to Anthracnose of green gram (Vigna radiata)

Abstract

Anthracnose of green gram caused by Colletotrichum truncatum (Schwein.) Andrus and W.D. Moore occurs severely in Indo- gangetic plains every year. Experiment was conducted for two consecutive years (2013 and 2014) to assess yield losses to develop yield loss models. The linear regression models were developed by two parameters i. e. percent yield loss and avoidable yield loss as dependant variable and area under disease progress curve (AUDPC) as independent variable. The two years pooled mean revealed that a drop of 0.3 to 0.33 qha-1 in pod yield and a drop of 0.16 to 0.20% in avoidable yield loss of pod yield due to every 1% increase in AUDPC. Three sprays of Propiconazole 25 EC (0.1%) at 10 days interval beginning from 20 days after sowing resulted in lowest anthracnose under moderate disease pressure and four sprays for high disease pressure resulted in highest pod yield of 5.17q/ha and 5.08q/ha respectively. Highest avoidable losses of pod yield and percent yield loss over potential yield due to anthracnose were 48.82% and 3.55% for three sprays and 49.74% and 1.77% for four sprays respectively. The result also showed that three sprays of fungicide (Propiconazole 25 EC @ 0.1%) resulted in minimizing the disease and maximizing the profit by high benefit cost ratio (B:C) ratio.