Effect of Abiotic Inducers on Purple Blotch (Alternaria porri) and Black Mould of Garlic (Aspergillus niger)

Abstract

The present study aims to evaluate the efficacy of different abiotic resistance inducers in promoting disease resistance and growth in garlic. Purple blotch caused by Alternaria porri and black mould of garlic caused by Aspergillus niger is the most devastating disease infecting garlic during storage. The field experiment was conducted to study the efficacy of abiotic resistance inducers during the year 2019-2020. A variety of garlic was sprayed after 60 days of sowing with abiotic inducers viz. Sodium salicylate (20mM,50mM), Salicylic acid (20mM,50mM), Potassium hydroxide (200mM, 300mM) and Potassium dihydrogen phosphate (50mM,100mM) to check the growth of disease. Data was recorded in terms of disease index (%) after 45, 60 and 75 DAT for purple blotch of garlic. The first spray of abiotic resistance inducers was applied at 45 DAS, followed by three additional foliar sprays at 15-day intervals. After harvesting, the garlic bulbs were inoculated artificially with Aspergillus niger. Minimum disease index after 45, 60 and 75 DAT of 26.11, 42.78 and 61.21 per cent was recorded with Salicylic acid 20mM. After harvesting, Minimum disease incidence and index were recorded with Potassium dihydrogen phosphate (100mM) and Potassium hydroxide (300mM). A maximum yield of 2.00 kg per plot was recorded with Potassium dihydrogen phosphate (100mM), whereas a minimum yield of 0.86 kg per plot was recorded with Potassium hydroxide (200mM).