Physiological and Agronomic Performance of Domesticated and Wild Cotton Germplasm from Selected Regions of Kenya

Aims: Cotton (Gossypium species) occupies a prime position as a fibre crop of the world used for making cooking oil, soup and seed cake for animal feed industry among other uses. Performance of wild cotton germplasm in Kenya has not been well studied and therefore there is need for understanding the correlation of traits influencing seed cotton productivity for effective improvement of the standard HART 89M. The study aimed at determining the correlation in performance between domesticated cotton HART 89M with wild cotton.

Experimental Layout: Four wild cotton species and HART 89M were planted in three experimental blocks, each measuring 6 m by 30 m. There were three replications per experimental block, the distance between blocks was 2 m. The experimental blocks were then divided into 5 plots of 5 m by 5 m, with 1 m separating plots. The cotton seeds were planted in rows of 1 m by 0.5 m at depth of 2 cm.

Methodology: Data on agronomic traits such as germination rate, flowering rate, height, number of fruiting branches, length of the longest fruiting branch, internodal length, number of nodes on the longest fruiting branch and yield per plant was collected from a sample of forty-five plants. One way Analysis of Variance (ANOVA) was used to determine the significant difference among the studied species and varieties at P = 5%.

Results: There was a significant difference between the standard genotype (HART 89M) and studied wild genotypes with G. barbadense having highest height (203.37 cm), number of fruiting branches (66.93 cm), length of the longest fruiting branch (68.36 cm), number of nodes on the longest fruiting branch (5.38) and productivity (205.21 g) compared with other genotypes. G. kirkii had the longest intermodal length of 6.36 cm.

Conclusion: On boll traits the highest significant difference with HART 89M was found with G. kirkii on boll weight (3.71 g), seed weight (2.30 g), and lint weight (1.41 g). Cotton breeding programs should consider traits such as plant height, number of fruiting branches, number of nodes on the longest fruiting branch, boll weight, seed weight and lint weight during selection as they were the major attributes of the seed cotton productivity. G. herbaceum and G. kirkii were recommended for seed production.