Stempedia a weatherbased model to explore and ma

Authors: Moin U Salam Tapan K Day Ashraf U Ahmed Bodrun Nessa A H M Mahfuzul Haque Subash Subedi Al Imran Malik M Matiur Rahman William Erskine

Publish Date: 2016/08/03

Volume: 45, Issue: 5, Pages: 499-507

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Abstract

Lentil Stemphylium blight is a fungal disease threatening sustainable lentilbased cropping in South Asia including Bangladesh A weatherbased model ʻStempediaʼ was developed to understand the risk of the disease Daily maximum temperature and sunshine hours are the two most important parameters of the model When tested with field data from Bangladesh and Nepal the model simulated the disease severity well both without R 2  = 089 n = 17 and with R 2  = 080 n = 18 fungicide application scenarios As a result Stempedia was subjected to experimentation to explore the risk and risk management options related to the disease under Bangladesh conditions Taking Gazipur a central regional district as an example the model identified that predominantly gradual reductions in sunshine hours or increased cloudiness during the early part of the ‘disease susceptible window’ had increased the disease severity over the last 30 years The model simulated Ishurdi a northwestern regional district as more disease prone than Gazipur and Jessore a southeastern regional district Stempedia simulated seasonal variability of the disease and predicted reduced severity with delayed sowing the magnitude of which differed between regions Stempedia also predicted financial returns with three foliar applications of an effective fungicide but this depended on the timing of application The best financial return occurred with an early fungicide application as soon as the disease appeared during initiation of flowering followed by further applications if a diseaseproducing environment was expected We conclude that the model has potential to assess regional and seasonal risks of this disease and to determine risk aversion by manipulating sowing time This model can further be used to formulate the principle of foliar fungicide application to achieve financial gainFunding for this research was provided by the Australian Centre for International Agricultural Research ACIAR under project CIM/2009/038 The study was undertaken by the senior author when he was on unpaid leave from the Department of Agriculture and Food Western Australia DAFWA Australia

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