Six diverse strains were used to produce 45 possible double crosses. F2 of these hybrids were raised in randomized block design with 3 replications. The data were analyzed, according to Rawling and Cockerham (1962) model. The most important aspects of the double-cross hybrid was relative importance of the arrangement of parents i.e the order effect in these hybrids.
The Suvin (P5), Australian (P1) and BBB (P2) were the best as one parent for seed cotton and lint yield, lint percentage and upper half mean respectively. The highest 2-lines of general effect were exhibited by (P2 x P3), (P1 x P3) and (P1 x P2) for seed cotton and lint yield, lint percentage and fiber length respectively. The highest specific effect of 2-lines interaction with arrangement were (P1 x P4) (- -),(P1 x P3) (- -) and (P2 x P5) (- -) for the same traits respectively, while its irrespective arrangement was (P1 -) (P3 -) for seed cotton and lint yield and lint percentage and it was (P1 -)
(P4 -) for fiber length.
For 3-line interaction with arrangement were (P4 x P5)(P1-) (P1 x P2) (P5 x -) and (P1 x P4)(P6-) for the same traits respectively. While irrespective of order were (P1 x P4)(P5 -), (P1 x P3)(P4-) and (P3 x P6)(P6-).
For the best 4-lines interaction with arrangement and irrespective were (P2 x P4) (P5 x P2) for seed cotton and lint yield, and for lint percentage (P1 x P6) (P2 x P3) were the best in case the arrangement, while the best irrespective arrangement were (P2 x P4)(P5 x P6). With respect fiber length the best 4-lines interaction with arrangement were (P1 x P3) (P2 x P5) and (P2 x P5) (P4 x P6) while the best irrespective arrangement were (P1 x P2) (P4 x P6).