Impact of elicitor spray on Alternaria blight severity and yield of Brassica juncea and Brassica napus species

Abstract

The effect of two elicitors viz., salicylic acid (SA) and benzothiadiazole (BTH) was studied to control
Alternaria blight caused by Alternaria brassicae in Brassica juncea and B. napus varieties. The elicitors
were applied alone, and in combinations viz., 10 ppm BTH (treatment-1), 50 ppm SA (treatment-2), 3 ppm
BTH + 33 ppm SA (treatment-3), and 7 ppm BTH + 17 ppm SA (treatment-4). Fungicide-blitox and watersprayed
control were used as treatment-5 and treatment-6, respectively. Both the treatment combinations of
elicitors i.e. treatment-3 and treatment-4, were effective in reducing the disease severity in both B. juncea
and B. napus on all weeks of observation as compared to control and fungicide. In 13 week old B. juncea
plants, treatment-3 showed 33.9% reduction in disease severity as compared to control. In 11 week old
B. napus plants, treatment-4 showed 38.3% less disease severity than control. There was 28.4% and 22.9%
increase in seed yield of B. juncea plants treated with treatment-3 as compared to control and fungicide
treated plants, respectively. In B. napus, treatment-4 showed 27.1% and 21.5% increase in seed yield as
compared to control and fungicide treated plants, respectively.