Development of Compact Cotton Strains for High Lint Productivity in Gossypium Hirsutum L. I. Breeding Procedure and Selection

With a view to develop short-branch, high yielding, high ginning varieties with superior quality fibre so that 6–8 times the normal plant population could be accommodated, a unique procedure involving composite crossing among F₁ was followed. Initially, nine F₁ plants were crossed among themselves in all possible combinations. Intensive selection of plants in the population grown with seeds obtained by composite crossing (S_o generation) having 1–3 noded short sympodia and repeated composite crossing between them resulted in the development of short-branch strains with no dried flowers, high ginning and superior fibre quality, which formed JK 400 series of cotton (G. hirsutum L.) varieties. Some of these strains produced 41.8 q/ha seed cotton under rainfed conditions with 36–47% ginning out-turn (GOT), 25–33 mm 2.5% spaa length fibre. Fibre strength, hand tested in the field before assessment in the laboratory, gave 8.19 to 9.36 PSI values with the fibre having 3.7–4.4 micronaire values. The bleeding procedure and method of field selection are discussed.