The American bollworm, Heliothis armigera Hüb. is the major cotton pest in Tanzania. The commercial cotton varieties have the ability to compensate for early loss of fruiting points caused either by physiological stress or by bollworm damage; and therefore early sowing, together with a blanket spraying regime, is recommended to minimize the damage caused by this bollworm. To extend this integrated approach, studies to incorporate Heliothis -resistant characters, viz. frego bract, nectariless, high gossypol and glandless into the Ukiriguru cotton varities, were started in the early 1970s and are still in progress. To date, frego bract has given consistently good results; and intensive work is under way.
