MANAGEMENT OF PURPLE BLOTCH OF ONION THROUGH CHEMICALS AND PLANT EXTRACTS

Abstract

A field experiment was conducted at the research farm of Sher-c-Bangla Agricultural University. Dhaka. Bangladesh during the rabi season of 2006-07 to study the management of purple blotch of onion through chemicals and plant extracts. The experiment was laid out in a Randomized Complete Block Design extracts was found on the management of purple blotch of onion including, tested in the experiment. A positive and significant effect of fungicides and plant 250 EC. Ridornil Gold. Neem leaf extract, Alamanda leaf extract and Control were Rovral SOWP. Bavistin SOWP. Cupravit 50WP. Proud 250 EC. Champion, Tilt (RCBD) with 3 (three) replications. Eleven treatments comprising Dithane M-45. germination. plant height. bulb diameter and bulb) ield of onion. The highest bulb yield (8.767 t/ha) and bulb diameter (3.787 cm) were obtain with Rovral SOWP. The percent plant infection. percent leaf infection. percent Leaf Arca Diseased ('%LAD) and Percent Disease Index (PDI) were found the lowest in foliar spray with Rovral 50WP. Between the two plants extracts Neern leaf extract performed better then Alamanda leaf extract.