Temperature-based prediction and validation of pink bollworm, Pectinophora gossypiella infestation on cotton crop

Abstract

Pink bollworm Pectinophora gossypiella infestation on cotton now a days found to be a major alarm to cotton crop in Pakistan. The effect of past and future temperatures climatic factors on the infestation rate of pink bollworm needs to be extensively studied. Field visits were organized in different areas across 17 main districts of Punjab, Pakistan, for eight consecutive years from 2012 to 2019. Based on past data, the pink bollworm infestation rate for the year 2040 was estimated. Our results showed an extensive infestation of pink bollworm on cotton throughout the visited locations between 0.1 and 35.7 % range above the economic threshold level, that cause reasonable cotton productivity losses. Based on the results of historical data of infestation rate, the nine of the 17 districts (53 %), Bahawalnagar, Bahawalpur, Faisalabad, Jahang, Mianwali, Multan, Muzaffargarh, Rahimyar Khan, and Lodhran, showed significantly (p < 0.05) higher pink bollworm infestation rate than the other cotton-growing areas. Moreover, the systematic increase level of pink bollworm infestation was predicted in 2040, especially in the five districts, Bhakar, Jahang, Khanewal, Faisalabad, and Vehari. Considering the importance of biological parameters, different temperature regimes (21 °C, 28 °C, and 35 °C) were tested for the validity of temperature-based prediction. Our results showed that growth capacity of P. gossypiella were increased at 28 °C. It revealed that, variation in weather due to current climatic condition with decreases of temperature increases P. gossypiella infestation on cotton crop. In this investigation, the effects of a severe outbreak of pink bollworm infections in Punjab's cotton-growing regions are discussed.