1- Bidhan Chandra Krishi Viswavidyalaya , poly.saha@gmail.com
2- Bidhan Chandra Krishi Viswavidyalaya
Abstract: (358 Views)
Powdery mildew (PM) of chilli is one of the major diseases affecting the yield and quality of chilli. Pathogen perpetuates in the infected crop debris and produce airborne conidia for rapid secondary spread. Prophylactic application of fungicides is admissible to keep the disease under threshold. Therefore, an experiment was designed to determine bio-efficacy and phytotoxicity of different doses of a new molecule combination (i.e KK-21: Sulphur 84% + Azoxystrobin 6% SC) along with optimization of its number of sprayings. This molecule was also compared with the most popularly used fungicides against PM of chilli. Additionally, influence of weather variables on the initiation and progression of the disease were also studied and prediction model developed by stepwise regression equation for timely forecasting and managing the disease. Study revealed, depending upon the prevailing weather the disease first appears between 44 to 64 days after transplanting then progress gradually at a rate varied from 0.0012 to 0.0139. Among the fungicides applied, three spraying of KK-21 @ 2500 ml/ha at 15 DI just after initiation of the disease was most effective with lowest disease severity index (5.00) and highest yield 150.24 q ha-1 and no phytotoxic effect was recorded even at higher dose. Result also showed, maximum temperature and relative humidity had significantly positive and negative correlation with the disease severity and the prediction equation demonstrated that these two factors could explain 78.2 - 87.6% of the variation in disease severity.
Article Type:
Original Research |
Subject:
Plant Protection/Plant epidemiology Received: 2023/12/24 | Accepted: 2024/01/1