ABSTRACT
Bollworms (Heliothis sp.) cause major economic damage to cotton (Gossypium sp.). High gossypol, "X-factors", nectarless and glabrous plant traits are known to impart bollworm resistance to the cotton plant. Red plant color in cotton has also been suspected to be less susceptible to bollworms. This study was conducted to compare the resistance in red leaf cotton (due to R(1) gene) with other cotton genotypes known to have some degree of resistance. Number of eggs laid, feeding damage to terminals, number of damaged fruiting parts and number of live worms on several different genotypes was compared under field conditions. It was observed that even though bollworm moths laid significantly more eggs on red leaf cotton, the damage to plant parts was significantly less than that on a regular cultivar. The red leaf cotton did not inhibit worm growth in the laboratory feeding studies. It is concluded that resistance in red leaf cotton genotype used in this study is due either to unknown factors similar to "X-factors" or due to R(1) gene.
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