The principle of cotton seed selection should be followed

What kind of cotton seeds are considered good cotton seeds? What principles should cotton seeds follow when selecting? The following ten points are for reference.

First, we must select the varieties approved by the Provincial Crop Variety Approval Committee. Second, we must see the variety number and the defined planting range. Third, we must see whether the variety has a production license, business license, quarantine certificate. The purity of four conventional insect-resistant cotton stocks should be over 98%, and the purity of hybrid insect-resistant cotton F1 should be over 95%. Hybrid F1 should be used as much as possible, and F2 should not be crossed. Fifth, it is necessary for farmers who have a large area of ​​cotton planting to guide them to choose one or two local main varieties. Sixth, we must use a certain bivalent (including two insect-resistant genes) transgenic cotton varieties, because the insect resistance of bivalent transgenic cotton is more stable and lasting.

Some cottonseed are not suitable for seeding. Cottonseed with severe susceptibility, dry and verticillium wilt is one of the stubborn diseases that restrict cotton production, and cottonseed is the carrier of pathogens. Therefore, cotton varieties in areas with severe dry and verticillium wilt cannot be transferred to cotton areas that are susceptible to disease, and cannot be transferred to disease-free cotton areas.

Fuqian peach and late autumn peach cottonseed. Fuqian peach and late autumn peach have poor growth and development, poor maturity, light boll, low seed germination rate and fragile growth.

Peach peeled cottonseed. Some cotton farmers still have a bad habit of robbing and peeling peaches. Any cottonseed that has been peeled off from peach blossoms, because it is not fully matured, does not complete the post-ripening effect and must not be introduced to the market.

Ethephon cottonseed is sprayed. Spraying ethephon can promote cotton early maturity for 3-4 days, but damage to cottonseed is large, resulting in incomplete development, can not be seeded.

Degraded varieties. Cotton is a cross-border crop with an outcrossing rate of about 8%. Some cotton farmers do not replace new varieties for many years. The purity of cotton seeds is only 70% to 80%. Continued use will definitely lead to a reduction in production.

Cottonseed stored with pesticides and fertilizers. Some farmers have long-term storage of cottonseed, pesticides and chemical fertilizers in a warehouse, and the ventilation is poor. The toxic gases emitted by pesticides and chemical fertilizers will damage the normal physiology of cottonseed, resulting in a sharp decrease in germination rate.

Store cotton seeds that are too old. The average germination rate of cotton seeds is more than 80% for half a year. In the absence of low-temperature refrigeration equipment, the life and storage age of cotton seeds are negative.

Cottonseed that has been sunburned on the cement. Cottonseed with higher water content in the cement drying field, due to the vigorous breathing strength of the cottonseed, causes the physiological function of the cotton seed to be out of tune, and some cottonseed form a dumb seed and lose the ability to germinate.

Mechanically damaged cottonseed. In the finished coated cotton, the mechanical damage rate should be controlled within 2%. Cottonseed with a seed smashing rate of more than 2% is heavily contaminated by the drug, which has a great influence on the germination rate and is not suitable for seeding.