Efficacy Evaluation of Abiotic Elicitors for the Management of Black Rot Disease of Cauliflower Incited by Xanthomonas campestris pv. campestris

Abstract

Aims: To find out the effective abiotic elicitor for management of black rot disease of cauliflower.
 Study Design: Completely randomized block design (Pot experiment in glasshouse condition).
 Place and Duration of the Study: This experiment was conducted at glasshouse of Division of Plant Pathology, ICAR-IARI, New Delhi during the year 2021-22.
 Methodology: Different abiotic elicitors were applied by spraying whole plants (45 days old) with the aid of a fine atomizer onto the upper leaf surfaces. Pathogen X. campestris pv. campestris was inoculated after 72 h of elicitor treatment, Control plants were treated with the distilled water. The disease assessment was done at 14 and 21 days after inoculation by using six- point scale and Percent Disease severity was calculated.
 Results: In case of foliar spray of Salicylic acid before 72 h of inoculation of pathogen, minimum percent diseases severity (25.56) was recorded at the concentration of 3 mM after 21 days of pathogen inoculation. In case of BABA, minimum percent disease severity (18.37) was observed at 800 \(\mu g/ml\) concentration. INA helps to reduce the disease severity at 100 uM concentration. ASM was found effective at 350\(\mu g/ml\) with 14.07% disease severity and 82.91% disease control efficiency. In case of MeJA, minimum percent disease severity (30.32) was observed at 2mM concentration.
 Conclusion: Among all the tested abiotic elicitors at different concentration, ASM at the concentration of 350 \(\mu g/ml\)was found very effective to manage the disease.
 Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a very important and devastating disease of cauliflower (Brassica oleracea var. botrytis) crop resulting into 10–50% yield losses every year. So for the management of black rot disease, five abiotic elicitors viz; salicylic acid(SA-0.5, 1.0, 2.0, 3.0 mM), methyl jasmonte (MeJA-0.5, 1.0, 1.5, 2.0mM), \(\beta\)-Aminobutyric acid (BABA-200, 400, 600, 800 \(\mu g/ml\), acibenzolar-S- methyl (ASM-150, 250, 350, 450 \(\mu g/ml\)) and dichloroisonicotinic acid (INA-50, 100, 150, 200 \(\mu \)M) were tested to induce systemic resistance against the disease. The experiment was conducted under glasshouse condition at Division of Plant Pathology, ICAR-IARI, New Delhi during the year 2021-22. Foliar application of these abiotic elicitors was done on 45 days old plants of susceptible cv. Pusa Sharad of cauliflower. Results indicated that among all the tested chemical elicitors at different concentration, ASM@350 \(\mu g/ml\) was found very effective to manage the disease. It shows 82.91% disease control efficacy with 14.07% disease severity.