Correlation of weather parameters with the insect-pests incidence on cauliflower.
Three field trials were conducted at the Agricultural College Farm, Bapatla, Guntur, Andhra Pradesh, India during 1996-98 to correlate weather parameters with insect pest incidence for the possible prediction of pest occurrence on cauliflower cv. MM-9. Cauliflowers were raised on 20 November 1995 to 21 January 1996 (first cropping), 23 October to 31 December 1997 (second cropping) and 17 January to 27 March 1998 (third cropping). The pest counts were made at 5-day intervals starting from their first occurrence. The larval populations of Spodoptera litura and Plutella xylostella were negatively correlated with the maximum and minimum temperatures, while those of Crocidolomia binotalis [C. pavonana] and Brevicoryne brassicae were positively correlated with the evening relative humidity and minimum temperature, respectively, during the first cropping. The lepidopteran pests were negatively correlated with minimum temperature during the second cropping and were positively correlated with the evening relative humidity during the third cropping. The aphids were negatively correlated with the maximum temperature during the second cropping, whereas they were positively correlated with the evening relative humidity during the third cropping.