Effect of different NPK fertilizer schedules on the Stem rot of Jute (Corchorus olitorius L.) caused by Macrophomina phaseolina (Tassi) Goid

Abstract

In a field experiment, response of nitrogen, phosphate and potash fertilizer schedules was studied on the incidence of stem rot caused by Macrophomina phaseolina on a new jute variety JRO 8432 at CRIJAF, Barrackpore during 2012 - 13. Application of more nitrogenous fertilizer enhanced stem rot of jute. But increase in phosphatic and potassic fertilizers reduced stem rot. Among the different NPK fertilizer schedules, 120:30:30 attracted more stem rot of jute with 47.9 % disease at 120 DAS, followed by 120:40:40 with 40.5 %, 100:30:30 with 36.1 % and 80:40:40 with 35.2 % stem rot. With similar dosage of nitrogen, when phosphate and potash were increased, lower stem rot was recorded. Phosphate and potash fertilizer moderated the effect of deleterious effect of nitrogen by reducing the stem rot incidence. In check, stem rot increased from initial 0.3% to 2.2% in 45 days and finally to 21.6 % during the maturity of the crop. But in different NPK fertilizer treated plots, dynamics of stem rot was different showing varied interaction. The progress of disease over time was typically slowest in case of NPK 40:30:30. Higher level of nitrogen with phosphorus and potash not only increased susceptibility of jute plants and killed more plants due to high prevalence of stem rot disease but also increased dry fibre yield.