Varietal performance against sucking insect pest of cotton (Gossypium hirsutum L.) under Multan ecological conditions

The ten cotton varieties were screened for resistance against whitefly, jassid and thrips at the experimental farm of Cotton Research Institute (CRI), Multan. Among the selected genotypes, SLH-284 exhibited relative resistance to whitefly, while VH-156 showed low susceptibility to thrips (0.7/Leaf). Notably, SLH-284 displayed greater resistance to whitefly attack. In August, a high jassid population (5.6/Leaf) was observed. Cotton genotypes BH-167, FH-113, and VH-148 were found to be susceptible to high infestations of insect pests, resulting in reduced cotton yield. In addition, jassid indicated peak population during August. The result indicated that VH-156 showed the resistance against thrips. From this experiment, it was observed that low infestation of whitefly and thrips occurred on SLH-284 and VH-156 cultivars. So, the overall results showed that VH-156 and SLH-284 can be used in IPM program. The study aimed to explore the impact of varied spacing and abiotic factors such as temperature, rainfall, and relative humidity on the population dynamics of sucking insect pests (specifically Bemisia tabaci, Thrips tabaci, and Amrasca devastans) within unsprayed conditions. A simple correlation analysis was employed to discern the relationships between these variables. The results of the analysis revealed that rainfall and temperature had a significant and positive impact on jassid populations, whereas relative humidity showed a non-significant effect. Similarly, temperature exerted a positive influence on both thrips and whitefly populations, while relative humidity and rainfall did not exhibit a significant impact on thrips. For whitefly, a significant and positive correlation was observed with relative humidity, but rainfall did not show a significant impact. To further quantify the relationships, Multivariate Regression Analysis computed the coefficient of determination (R2). The results indicated that temperature, humidity, and rainfall collectively influenced 53 %, 36.8 %, and 66.4 % of the population fluctuation of jassid, thrips, and whitefly, respectively. These findings underscore the intricate interplay of abiotic factors in shaping the dynamics of sucking insect pests, providing valuable insights into the environmental determinants of their populations under unsprayed conditions. © 2018 The Author(s)