INFLUENCE OF DIFFERENT COTTON VARIETIES AND GENOTYPES ON THE INFESTATION BY THE SPINY BOLLWORM Earias insulana (BOISD.)AT KAFR EL-SHEIKH GOVERNORATE

The present work was carried out during two successive seasons (2012 and 2013) at Farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt to evaluate the influence of different cotton varieties and genotypes on the infestation by the spiny bollworm Earias insulana (Boisd.) at Kafr El-Sheikh Governorate. Results during the two experiments showed the infestation percentage of SBW to six cotton varieties and genotypes of both seasons were (8.14, 7.64, 7.66, 6.08, 7.16 and 8.36%) for Giza 86, Pima S6 x Giza 77, Giza 92, Giza 94, Giza 86 x 10/229 and Giza 88, respectively. The highest means of infestation % were recorded in the G.88 and G.86 in both seasons, while the lowest means of infestation% were recorded in the G.94 and G.86 x 10/229 in both seasons. The differences among means of infestation % may be due to the differences of gossypol % in wall thickness of green boll. The means of gossypol% in green boll wall were (1.78, 1.32, 1.44 0.91, 1.75 and 1.16%) and the means of wall thickness were (2.77, 2.38, 2.07, 2.82 , 3.04 and 2.94 mm) for above cotton varieties and genotypes during both seasons, respectively. There were highly significant differences among the cotton varieties and genotypes in some characters.