Studies On Biological Effects Of The Cotton Seed Pelleting

Three cotton (Gossypium barbadense Linn.) varieties Jimian 27, Hengmian 3 and Hengmian 210 were investigated. The adaptable adhesives and spraying device for cotton seed pelleting were picked out. Compared with coated control, researches were carried out about the biological characteristics in the germinating process, the cotyledon stage and the leaf stage. The cotton seed pelleting on improving the seed germination, the seedling growth, the resistance ability and the yield were studied and approached. The main results were summarized as follows:1. The adhesives and spraying device with good and safe characters were picked out by studying the effects of different adhesives and spraying devices on cotton seed pelleting and the germination rate. The appearance of the pelleted cotton seeds were neat, could withstand certain pressure and kept normal germination.2. The soluble protein and soluble sugar and chlorophyll contents of seedling were raised in the different stages. The result indicated that seed pelleting has accelerated nutrient transformation of cotton seed obviously. The plant photosynthesis was enhanced, photosynthesis matter accumulating were increased. This provided sufficient energy and material base for later nutrition and reproduction growth and effectively promoted the seedling stronger and growth earlier.3. The MDA content and the relative electric conductivity of the pelleted seedling in the different stages were lower than the coated seedling remarkable. It showed that pelleting could strengthen the repairing ability of biomembrane during the germination and growth process, suppressed the free radicals production effectively, prevented the important nutrient substances leakage. These strengthened the cold-resistance and injury-resistance ability in the adverse circumstance during seedling growth process.4. The field experiment indicated that the pelleting treatment could promote nutrient absorption and accumulation in cotton seedling, improved the N, P, K contents of seedling. Thus the nutritions which the seedling growing needed were increased and the cotton seedling growth were promoted5. The protecting enzymes of seedling were studied through the field experiment in the cotyledon stage. The results showed that the effective components in raw material of pelleting could enhance the protecting enzymes activity. Compared with coated control, the activities of POD, CAT and PPO increased by 46.94%-58.62%, 14.28%-61.16%, 42.28%-44.86% respectively of three cotton varieties. The H₂O₂ decomposition was sped up and the free radical contents decreased, thus could protect membrane structure avoiding injury, which afforded a physiological foundation for increasing the disease-resistant ability of seedling.6. Compared with coated treatment, the pelleting treatment could promote cotton seed vigor, be good to germination and emergence, simultaneously enhanced the agricultural chemicals precaution and control effects, strengthened the resistance ability in the adverse circumstance. The seedling establishment rate in laboratory and field were improved by 7.5%-10.83% respectively. Pelleting was good to matter accumulation and growth, shoot height, radical length, fresh and dry weight of single seedling, vigor index significantly were higher than that in the coated control. The yield increased by 11.62%-37.11%, average production increased by 20.79%.