Evaluation of Growth Media Incorporating Cotton Ginning By-products for Vegetable Production
The suitability of by-products from the cotton ginning industry for incorporation into growth media for three vegetable crops was examined. Composts were prepared by mixing the by-product with soil in 5 ratios (20:80, 40:60, 60:40, 80:20, 100:0, v/v compost and soil). Seeds of lettuce (Lactuca sativa L.), radish (Raphanus sativus L.) and spinach (Spinacia oleraceae L.) were sown directly within the composts and in 100% peat (control) in October (autumn crop) and December (winter crop). Plant growth (height, leaf number, dry and fresh weight, chlorophyll content) was recorded 19 and 17 days after transplantation (first and second sowing respectively) and at harvest. Fresh and dry weight was recorded at harvest. Overall, plant height and leaf number were higher when the growth media consisted principally of compost (higher ratios of cotton by-product: soil) than in the control (peat), whereas among the various ratios of compost: soil significant differences were recorded, media with a high compost content showing better growth in most cases. Similar results were reported for fresh and dry weight and chlorophyll content, except for dry weight in the second sowing, where growth media with a lower compost content had a higher dry weight. In conclusion, the incorporation of the cotton ginning by-product into compost resulted in better growth of lettuce, spinach and radish, suggesting that the use of this material may be of economical value as a spin-off product for the cotton ginning plant and also as a means of reducing present pollution of the environment due to the accumulation of waste material.