VARIETIES BY ENVIRONMENT INTERACTION AND ITS EFFECTION ZONING EGYPTIAN COTTON

Abstract

Cotton in Egypt ranked first in relation to fiber crops and efforts are exerted to increase cotton production and quality through agricultural policies and breeding new varieties. It is well known that the productivity of any variety is the outcome of the interaction between the genetical constitution and environmental conditions. For this reason, cotton should be grown under suitable environmental conditions to achieve the highest yield and the best quality. Therefore, 30 field experiments were conducted during the three successive seasons 1992 , 1993 and 1994 at ten different regions:- - Upper Egypt (Sohag, Assuit, El-Minia and El-Faiyum). - Southern and Middle Delta (Dakahlia, El-Gharbia and sharkeih. - Northern Deha (Kafer El-Sheikh, El-Beheira and Damaitta), to evaluate 15 cotton genotypes of which twelve are the commercial varieties namely, dendera, Giza 45, Giza70, Giza 75, Giza76, Giza 77, Giza 80, Giza 81, Giza 83, Giza 84, Giza 85 and Giza 86, in addition to the three promising strains (Giza 75 x Rus. 6022), (Giza 77 x Giza 45A) and (Giza 77 x Giza 45B). Varieties and strains all together were grown following the routine adapted in the experimental stations. A complete randomized blocks design with four replications in each of the 30 environments (combination often locations in three years). Variance components and different stability estimates over location and years were calculated for seed cotton yield and yield components, in addition to fiber property traits.