Population Fluctuation of Bemisia Tabaci (L) and its Associated Predators under Combined E ors under Combined Effects of Sowing Date and V ects of Sowing Date and Varieties arieties

Abstract

The sowing date is very crucial among agronomic techniques for ensuring productivity and controlling insect pest. In 2018 and 2019, sowings were carried out 15 days intervals, starting on March 1 and ending on June 16. The dates were: March 1, March 16, April 1, May 1, May 16, and June 1. On advanced cultivars of Bt cotton, namely MNH-1026, MNH-1050, and IUB-13, the whitefly, Bemisia tabaci (Aleyrodidae: Hemiptera), and beneficial/predatory fauna were researched (control). The statistical analysis was multivariate. The relationship between the predatory fauna and the prey (whiteflies) in the correlogram was favourable. Predators showed a positive association with whitefly (0.592), boll weight (0.681), boll number (0.872), and seed cotton production (0.886) per acre, in that order. It was determined through Principal Components Analysis (PCA) that PC1 had an Eigen value >1 and accounted for 79.3% of the overall variation due to the greatest positive loading vectors. It was determined that because late planting had a short growing period, whiteflies attacked it less frequently. It was determined that short-season crop cultivation and the breeding of resistant germplasm are advantageous in the face of climate change.

Keywords

• predatory fauna
• sowing date
• agronomic practices
• short season cotton
• bt cotton