Abstract
Out of nine cultivars of cotton (GOSSypiIl11l hirsutum L.) tested for resistance in a replicated field trial at Gujrat, Pakistan, during 1990, only FH 90 and NIAB 78 showed some resistance against the stem damage by spotted bollworms (Earias insulana Boisduval) and E. vitella (Fabricius). Of the various physical and chemical factors, stem diameter, stem bark thickness, pith diameter, hair density on stem, number of necatries per leaf, crude proteins, crude fats and total sugars were negatively correlated to the spotted bollworms infestation. The number of gossypol glands on stem, moisture contents, fibre contents and mineral contents of stem were found to the positively correlated to the stem damage by spotted bollworms. Whereas hair density and gossypol glands on the leaves and fibre ring thickness did not play any role in imparting resistance in cotton to spotted bollworms.
