Influence of fungicides, nutrients and bioagents on leaf twisting disease and yield of onion (Allium cepa L.)

Abstract

Influence of fungicides, nutrients and bioagents on yield, quality enhancement and management leaf twisting in onion was studied at Regional Agricultural Station, Vijayapur, Karnataka, during kharif and rabi 2021-22. The variety of ‘Bhima Super’ seeds collected from two sources (normal and twisting affected seeds) with nine treatments combination of polymer (3 ml kg-1), chemicals, captan (2 g/kg), carboxin 37.5 % + thiram 37.5 % (3 g kg-1), captan 70 % + hexaconazole 5 % (3 g kg-1) and bioagents of Trichoderma harzianum, Pseudomonas fluorescens, and Bacillus subtilis each @ 5 g kg-1. The results obtained from combination of all three bioagents recorded significantly higher bulb yield (23.82 t ha-1) followed by all three bioagents along with fungicides carboxin 37.5 % + thiram 37.5 % (3 g kg-1) (23.15 tha-1) as compared to control (15.22 t ha-1) due to significant increase in the yield attributes. Kharif harvested bulbs treated with nine different treatment combinations and planted during Rabi season to know the effect of nutrients, fungicides
and bioagents on field performance and management of leaf twisting. Among treatments application of N: P: K @ 125:50: 125 kg ha-1 + Mg @ 30 kg ha-1 + S @ 45 kg ha-1 + B @ 3 kg ha-1 + Zn @ 4 kg ha-1 + foliar spray of hexaconazole 0.05 % at 30 and 60 days after planting recorded significantly higher plant growth parameters, lesser leaf twisting (17.44%) and higher seed yield (504.49 kg ha-1) as compared to control (34.99 % and 312.47 kg ha-1 respectively).