Causes and Countermeasures for the Emergence of Cotton in the Coastal Areas of Jiangsu Province

1.4 Influence of soil

1.4.1 The cover soil is too thin or too thick

Covered soil is too thin and easy to lose water, some cotton seed shells can not fall off, with more "hat" seedlings; too thick will affect the permeability, so that some germinating weak seeds can not top soil emergence.

1.4.2 Covered Seed Poison

Covered seed soil is contaminated with herbicides from previous wheat crops. The main symptoms are uneven emergence, malformed seedlings are more and evenly distributed, and some cotton seedlings gradually shrink and die after unearthing.

1.5 seed factors

1.5.1 Seed maturity is not enough

The seed produced in the south of the Yellow River, during the seed growing season, if the rain is too high and the sunshine is insufficient, the postharvest action is not in place. Although the germination rate is up to standard, the germination rate is not strong and the germination rate is slow. The performance of the field was uneven, and the seeds that did not emerge in the dissection were viable. They were still emerging after 20 days of sowing, and the seedling stage was significantly delayed. In the spring of 2004, a cotton seed produced by a company in the province was tested by the Ministry of Agriculture. The germination rate was 86%, but the emergence of a large area after the broadcast was not uniform.

1.5.2 New and Chen sowing in the same seedbed

Practice has proved that: After 1 year of normal temperature or low temperature storage, cotton seed of qualified quality will be better finished due to post-maturation. Its germination rate can generally be increased by 2% to 5%, while germination power is increased by about 10%. The new and Chen seeds were sown in the same seedbed. Chen was generally 2 days ahead of schedule.

1.5.3 different varieties sowed in the same seedbed

Different origins, different varieties, they have different characteristics and physiological characteristics. The varieties originating in the Yangtze River valley include the Xiang-Shu cotton series, the Hubei-Cang cotton series, some Su cotton, and the Yunnan cotton. Most of them have a slightly thicker seed coat and a slightly slower rate of water absorption. The varieties produced in the Yellow River valley include cotton. Series, Lu cotton series, cotton series, etc., most of them are thin seed coat, seed water content is generally lower, faster water absorption. These different varieties are sown in the same seedbed, and the emergence of species in the Yangtze River Valley is generally delayed by 1 to 2 days.

1.5.4 Cotton seeds processed by different processing methods are sown in the same seedbed

Cotton has been used in all types of fleece-coated cotton. Since 1988, Jiangsu Province has promoted the use of foam acid or dilute sulphuric acid as a degreasing technique. The seed coat has good permeability through the use of foam acid or diluted sulphuric acid. The speed of water absorption is quick and neat. In recent years, many cotton seed producers have used mechanical polishing to remove cashmere. The seed processed in this way has not changed the seed shell structure, the waxy layer is still present, and the water absorption speed is similar to the hair seed. Seeds processed in these two ways are sown in the same seedbed, and the emergence of the latter is obviously delayed by 1 to 2 days. In addition, the ability of soil conservation in the coastal cotton area is poor, and the probability of seedlings is only about 50%, which is a relatively high risk.

2 measure measures

2.1 Scientific Application of Base Fertilizer

Organic manure, livestock manure and other organic fertilizers should be applied to the seedbed before winter. After the application, the soil is deep-frozen, so that it can be frozen and thawed alternately to achieve the purpose of combining soil and fertilizer. The urea was banned within 20 days before sowing, and special fertilizer for seedbed was also used 7 days before sowing. Basal fertilizer was banned from ammonium bicarbonate.