ENVIR ONME NTAL EFFECTS ON GENERAL AND SPECIFIC COMBINING ABILITY IN EGYPTIAN COTTON

Abstract

The stated objectives of this study was to evaluate stability of gca and sea under three different environments for several agronomic and fiber properties for six cotton varieties. A half-diallel genetic design of six parents, their 15 F 1 hybrids and 15 F populations were used. Parents are the commercial varieties of Giza 77 (P), Giza 81 (P2) and Dendera (Pas), and the other, are the three promising varieties; Giza 84 (P), Giza 85 (P) and Giza 83 x (Giza 72 x Delcero) (P,). Chosen parents, represent the range of variability existing in Egyptian cottons for most studied traits. Crossing parental materials inters by the diallel system was initiated at El-Giza Agricultural Research center, to generate F's and their corresponding F's in 1992 and 1993 seasons. In 1994, the six varieties and their derived crosses were grown in the three different locations of Sacolta (Sohag governorate), Kenayate (Sharkiea govemorate) and Sakha (kafr El-Shiekh govemorate). The experimental layout was a randomized complete blocks design with three replications. Characters evaluated for gca and sea were:•