Effect of <i>Alternaria</i> blight on the seed yield of cauliflower (<i>Brassica oleracea</i> L.)

Abstract

Effect of Alternaria blight (Alternaria brassiceae and A. brassicicola) on seed yield of cauliflower (Brassica oleracea L. var. botrytis) was studied during three consecutive growing seasons (2003-2004, 2004-2005, and 2005-2006) in winter under natural epiphytotic condition. There were two treatments viz. sprayed and unsprayed. BARI Cauliflower-1 was used as planting material and Rovral 50 WP (Iprodion) at 0.2% suspension was used as protective chemical to safe the crop against Alternaria brassiceae and A. brassicicola. Percent pod infection, pod area diseased, number of pods/plant and seed yield differed significantly between the sprayed and unsprayed (control) plots. Percent pod infection and pod area diseased ranged 35.3-62.4% and 94.7-97.6%, 1.9-2.2%, and 10.8-16.4% in sprayed and unsprayed plots in different, respectively. The number of pod/plant was 462-592 in sprayed and 281-395 in unsprayed plots. The seed yield/ha ranged 249.4-355.1 kg in unsprayed plots and 456.8-677.0 kg in Rovral sprayed plots. The seed yield increase were 59.6%, 171.4%, and 75.2% in 2003-2004, 2004-2005, and 2005-2006 cropping seasons, respectively.

Keywords: Alternaria blight; seed yield; cauliflower.

DOI: 10.3329/bjar.v35i3.6444

Bangladesh J. Agril. Res. 35(3) : 381-385