AGRONOMIC FACTORS ASSOCIATED WITH STEM ROT OF BERSEEM (Trifolium alexanderinum L.) IN SARGODHA, PAKISTAN

Stem rot of berseem (SRB) caused by Sclerotinia sclerotiorum (SS) is the most devastating and cosmopolitan plant disease, and infecting more than 400 species of plants worldwide. The disease is reported to cause more than $200 million losses. In Pakistan, the disease is infecting all cultivars of Berseem and causing heavy losses. The Sargodha district is the main Berseem cultivation area of Punjab, Pakistan. Agronomic practices are playing key role in its spread and dissemination to new fields. The hypothesis of current study was that this disease may be curtailed by altering agronomic practices. Hence, the following study was planned on the objective to evaluate the effect of agronomic practices of district Sargodha farmers on the disease incidence (DI) of SRB. To accomplish this objective, a detailed survey was arranged in seven tehsils of Sargodha during Berseem season in 2020-2021. The surveys were repeated every fifteen days throughout the cropping season. The villages and fields were selected randomly during the surveys. Every field was divided into five sections to note down the DI of SS. Agronomic practices surveys showed significant effect on SRB incidence in different tehsils. However, the effect of agronomic practices was different in different tehsils of Sargodha. In tehsil Kotmomin and Sargodha, canal irrigations, four number of irrigations, citrus inter-cropping, October and September-October cropping seasons, respectively, significantly (P < 0.05) decreased DI of SRB. In tehsil Sargodha, canal irrigations, four number of irrigations, citrus inter-cropping, and October cropping season significantly (P < 0.05) decreased DI of SRB. In tehsil Shahpur, canal irrigations, six number of irrigations, September cropping season and citrus intercropping significantly (P < 0.05) decreased DI of SRB. In tehsil Sahiwal and Sillanwali, tube-well+ canal irrigations, four number of irrigations, mustard and citrus inter-cropping, respectively, and October cropping season significantly (P < 0.05) decreased DI. It was concluded that change in agronomic practices could help lessen the SRB incidence in district Sargodha. The current study sets the foundation of future study to further investigate the role of different agronomic factors to eco-friendly manage SRB.