THE IMPACT OF SOME PHYSIOMORPHIC CHARACTERS OF SUGARCANE GENOTYPES ON THEIR RESISTANCE AGAINST SUGARCANE PYRILLA, Pyrilla perpusilla Wlk. (Lophopidae: Homoptera)

Field trials were conducted in the Research Area, Directorate of Sugarcane, Ayub Agricultural Research Institute, Faisalabad to study he physio-morphic characters of sugarcane resistance to the sucking pest Pyrilla perpusilla. Twenty genotypes of sugarcane were tested for their resistance susceptibility against P. perpusilla, as a preliminary screening experiment, during 2006. Based on the population-density count, 3 genotypes, viz., HSF- 240, CPF-243 and S-2002-US-114 showing resistance responses, 3 genotypes viz. CPHS-35, S- 2003-US-394 and S-2003-US-623 showing susceptible trends and 3 genotypes viz. S-2003-US-809, S-2002-US- 140 and S- 2002-US-104 exerting intermediate trends against the pest under test were selected for the final screening trials during 2007.The genotype S-2003-US-623, was found to be comparatively susceptible; whereas, HSF-240, showed resistance responses. The leaf-width and cane length showed a positive and significant correlation whereas the leaf-spine density had a significant negative effect with pest-population. The Leaf- length and Cane- Diameter did not show a significant correlation with the pest population.