Impact of varieties and delinting methods on growth, yield and quality of cotton (Gossypium Hirsutum L.) lint and seed

Thesis

Two experiments were conducted at Agricultural Research Institute Ukiriguru, Mwanza, Tanzania to evaluate the effectiveness of cotton varieties and cottonseed-delinting methods on seed quality, growth, yield and quality of lint and seeds. A completely randomised design (CRD) experiment with four replications to assess cottonseeds quality of three cotton varieties (UK77, UK 82 and UK 91) delinted mechanically, by using concentrated (98%) sulphuric acid, dilute (49%) sulphuric acid, Tanzania Cotton Lint and Seed Board [TCLSB] sulphuric acid methods and non-delinted seeds applied as a control giving 15 treatment-combinations was conducted. A randomised complete block design (RCBD), with a split-plot field experiment replicated four times with similar treatment-combinations was conducted to determine their effectiveness on cotton crop growth, yield and quality of lint and seeds. The crop was sown at two-rows, 45 cm apart on either side of a 1.5 m ridge with six seeds per hill 45 cm apart, which were later on thinned to two plants 35 days after planting. Data on seed quality, crop growth, yield, lint and fibre quality were collected and analysed. Laboratory experimental results obtained indicated that seed quality (germination percentage) was significantly affected (P <0.001) by the treatments applied; best quality being from the use of concentrated (98%) sulphuric acid. Growth and development variables were not significantly affected (P <0.05) by the treatments used, yield of seed­ cotton and lint were significantly affected by the cotton-varieties at P <0.05 and the interaction effects (P <0.001) of varieties x delinting methods used. Fibre quality was also significantly affected (P <0.05) by the treatment interaction-effects. Based on these results, for best cotton-seed quality, optimum seed-cotton and lint yield, and fibre quality, farmers should use delinted UK 91 and UK 77 cotton-seed varieties by using concentred (98%) sulphuric acid or TCLSB sulphuric acid methods.