Abstract:
A field experiment was conducted to evaluate the nine treatments using botanicals, nutrients and fungicides
against purple blotch of onion caused by Alternaria porri. Both fungicides and botanicals were used as seed
bulb treatments and foliar spray while the three nutrients B, Sand Zn were applied to the soil of unit plots under
all treatments as basal dose except control. The experiment was laid out in a randomized complete block design
CRCBD) comprising three replications. The highest reduction of disease severity of purple blotch of onion was
obtained by the application of Rovral 50 WP @ 0.2% in combination of nutrients followed by Ridomil Gold
MZ-72 @ 0.2% with nutrients and gave the maximum height of umbel stalk, number of onion seed stalk",
number of umbel plot", umbel diameter, 1000 seed weight and seed-yield, The highest onion seed yield 650 kg
ha" was recorded from the application of Rovral 50 WP @ 0.2% combination with nutrients followed by 590
kg ha-I from Ridomil Gold MZ-72 @ 0.2% adding with nutrients. Neem leaf extract gave the better
performance than Allamanda leaf extract in reducing the disease incidence, severity and increasing seed yield
and improving yield contributing characters of onion. The most effective fungicide was Rovral 50 WP followed
. by Ridomil Gold MZ-72 and Dithane M-45 gave 61.11, 48.15 and 42.65% reduction in disease severity and
58.64,43.90 and 39.83% increase in seed yield, respectively. At least eight sprays with seven days interval are
required to achieve satisfactory results.
