Comparative analyses of morphological, anatomical and nutritional traits of cotton cultivars in relation to Bemisia tabaci (Hemiptera: Aleyrodidae)

Leaf morphology, anatomy and nutritional traits of ten cotton cultivars were correlated with the whitefly, Bemisia tabaci (Gennadius) incidence. The cultivars namely, LD 327, P 59, HS 1300 and P 1752 had less incidence of B. tabaci ranging from 1.9-2.8 adults per leaf with higher density of glandular and non-glandular trichomes; in terms of length of trichomes and distance to phloem tissue the cultivar F 2036 had the longest while it was the shortest in LD 327. The latter was also unique in having the thinnest leaf lamina (216 μm) and the least protein content in the leaf (0.40 mg/ml). The cultivars with higher B. tabaci incidence were found to have maximum calcium, chlorine and sodium contents in their leaves, while the cultivars with less incidence had higher magnesium, sulphur and potassium contents. The cultivar LD 327 which showed least incidence of B. tabaci revealed a positive correlation as regards density and length of trichomes, distance to phloem tissue, and sulphur and potassium contents with whitefly incidence.