Cotton seed: never harvest prematurely opened bolls; pay attention when saving and selecting seed
According to data from seed management department testing, in recent years the germination rate of some cotton seed has been only around 60%, still far from the national standard of 80% germination rate. From extensive surveys, the reasons for low cotton seed germination rates are: first, harvesting immature prematurely opened bolls; second, purchasing "favor bolls" with high moisture content; third, mixing in diseased seed from rotten cotton bolls; fourth, storing cotton seed in the warehouse before it is fully sun-dried; fifth, containing some cotton seed broken during processing; sixth, relatively high residual acid content in coated cotton seed; seventh, not strictly grading harvested cotton; eighth, a high proportion of autumn boll cotton. Among all these factors, prematurely opened bolls have risen to become the main problem.
It is understood that the reasons farmers harvest prematurely opened bolls are: first, fear that others will steal cotton in the field; second, picking bolls during the day, so the whole family, young and old, can help open the bolls in the evening; third, prematurely opened bolls have a higher moisture content, so they can sell more wet cotton, selling more by weight while actually selling less cotton.
The increase in the proportion of prematurely opened bolls has become a major hazard to cotton seed quality and fiber quality. According to tests by research departments, fully mature cotton seed has a germination rate of 95.5%, mature cotton seed has a germination rate of 92%, semi-mature cotton seed has a germination rate of 63%, and immature cotton seed has a germination rate of only 14%. At the same time, the fiber grade, length, strength, number of convolutions and other quality indicators of prematurely opened bolls are greatly lower than those of mature cotton. Therefore, prematurely opened bolls must absolutely be rejected from seed cotton purchasing.
Cotton seed quality concerns the overall situation of cotton production. Accurately selecting and using high-quality cotton seed can lay a good foundation for high cotton yields. In order to improve the quality of harvested cotton, based on years of experience in various places, the following measures should be taken.
1. Formulate a policy of premium quality seed and premium quality cotton at premium prices, increase the value of premium seed and premium cotton, and use premium prices to motivate farmers to sell high-quality cotton.
2. Refuse to purchase "favor bolls" and prematurely opened bolls as seed cotton. Seed cotton should be mature cotton that has been open for more than 5 days. The moisture content of seed cotton should not exceed 12%, and the moisture content of cotton seed should be controlled at around 11%.
3. Advocate drying cotton on rack frames; cotton should not be dried on the ground, and even more should not be dried directly on concrete surfaces, to prevent the occurrence of dead seed.
4. Strictly grade harvested cotton, and ensure that dried cotton and dried seed enter the warehouse. Substandard cotton and post-autumn cotton before October 20 can only be purchased as commercial cotton, and must absolutely not be purchased as seed cotton.
5. Carefully select cotton seed, process and coat it, and eliminate inferior cotton seed.