Susceptibility of 13 okra genotypes to infestation with some pests as correlated to leaf morphology [electronic resource].

Includes references.

The present research work aimed to differentiate between thirteen okra genotypes from the point of its susceptibility to infestation by some sucking pests(Empoasca discipiens (Paoli) ,Aphis gossypii (Glover);,Bemisia tabsci (Genn.), Tetranychus urticae (Koch) and, Liromyaza trifolii (Burg)) during two summer plantation 2010 and 2011. Results clearly indicated that there was significantly positive correlation between the number of hairs on leaf lamina and population of whiteflies (r= +0.944**) and mites (r=+ 0.983**). Hairiness of the leaves influences the population of aphids, leaf miner, whiteflies, mite and leafhopper populations to the extent of 82,85.,89, 94 and97 percent, respectively. There was significantly negative correlation between pest population and mid-vein hair density for, leaf miner(r =- 0.928**) , aphids (r= -0.938**) and leafhopper (r= -0.985**), thus it appears to be an important factor in imparting biophysical resistance in okra against these pests. Whereas, significantly positive correlation was observed between population of whitefly, mite, and mid-vein hair density (r= +0.967**and+0.968**) favoring to the whitefly and mite population buildup. Influence of mid-vein hair density on different sucking pests population e.g., leaf miner, aphids, , whiteflies, mite and leafhoppers was to the extent of 80, 89, 94,97 and 98 percent, respectively. Overall impact of midrib thickness on the population of some pests e.g., whiteflies, aphids, leaf miner, mite and leafhoppers was to the extent of 64,72,75, 80and 88 percent, respectively.

Summary in Arabic.

1