Analysis Of Production Factors Affecting The Vigor Of Cotton Seeds

Cotton is an important economic crop in China, and the cotton seed is an important production material to guarantee the output of cotton. In order to solve the problem that the germination rate of cotton seeds is low, the vigor is low, the emergence of the field is not regular and the serious waste of the seeds, the study choose Luyan cotton 28 and Yinxing cotton 4, and research the key technology of improving the vigor of cotton seed. Research the production technology of high vigor cotton seed from ecological region, planting density and harvest site, setting boll stage; study the drying process of improving the vigor of cotton seeds from the aspects of seed drying methods and techniques. The main results are as follows:1. The health seed rate, thousand seed weight, the germination rate and seed vigor in Xinjiang was significantly higher than that of seed in Shandong Province, so Xinjiang is an ideal region for the production of high quality seeds. Between different parts of fruiting branches, seed reaped in Xinjiang, seed vigor had no significant difference. But that of seed in Shandong had some differences. Determination of physiological index showed that the high vigor seed had higher dehydrogenase activity, respiration intensity, SOD activity, POD activity and CAT activity. The results provided the basis for guiding the regional division of cotton seed production.2. Planting density test draws that the density has no significant effect on the seeds on the first boll, but it has significant effect on the seeds of the central boll of fruiting branches and the twig; About Luyan cotton 28, when we use the density of 6000 plants / mu, vigor of the seeds of the central boll of fruiting branches is the highest, but the branches' overall vigor in 4500 plants / mu is highest, so taking into account both the seed yield and seed quality to enable the seed company to obtain higher benefits, we should choose the density 4500 plants /mu; at the same time Yinxing cotton 4 should choose the density of6000 plants / mu.3. Determining the seeds from different parts of fruiting branches in the year of 2013 and2014, results showed that the change rule of healthy seed rate is that healthy seed rate of the seeds on the first boll and the central boll of fruiting branches was higher than that of the twig.There is stronger positive correlation to healthy seed rate and seed vigor. The change rule of seed vigor is that in the experiment of medium planting density, the seeds on the first boll seed vigor were the highest, followed by the seeds on the central boll of fruiting branches. In the experiment of high planting density, the seeds on the central boll of fruiting branches seedvigor were the highest, followed by the seeds on the first boll. With the planting density increasing gradually, high vigor seeds have a tendency to move toward the central boll. About the reaction of seed vigor to planting density, the seeds of mid-early maturity varieties were sensitive to mid-late maturity varieties. It is advisable to harvest the seeds on the central boll of fruiting branches which setting boll between July 21 st and August 15 th, and it is a way to improve seed vigor through imoroving healthy seed rate by mechanical processing.4. Determining the seeds from different setting boll stage in the year of 2013 and 2014,results showed that the change rule of healthy seed rate is that the seeds setting boll between July 21 st and August 15 th is higher than the seeds setting boll before July 20 th and the seeds setting boll between August 16 th and September 10 th. The change rule of seed vigor is that the seed setting boll between July 21 st and August 15 th was the highest, followed by the seeds setting boll before July 20 th, the seeds setting boll between August 16 th and September10 th was the lowest.5. In the seed drying process, under the premise of no producing heat of the seeds, storin g the seeds 10-30 days, the seeds' germination rate and vigor had no significant difference, c ompared with the seed dried immediately. Dry the seed which the initial moisture were 18% t o 11% moisture within the temperature range of 36-42?, there was no effect on the germinati on rate and vigor of cotton seeds. So we can dry the seeds in this temperature range.