Detailed introduction to the cotton variety Liaomian 15
Liaomian 15 is a new early-maturing upland cotton variety obtained by the Liaoning Academy of Agricultural Sciences through selecting superior variant plants from the Liao 1038 mixed line and carrying out years of directional breeding.
Characteristics: this variety has a growth period of 125-130 days, tall plants, a moderate plant shape, 1.5-2 fruiting branches, the first fruiting branch node at the 4th-5th node, and the first fruiting branch set at a height of 18-20 cm. The stem is thick and strong, the leaves are light green, and the root system is well developed. The bolls are oval and mostly 5-loculed, with a single boll weight of about 6.8 grams, and the cotton bolls are evenly distributed on the upper, middle and lower parts of the whole plant. Boll development is fast, and boll opening is smooth and concentrated; in ordinary years the pre-frost boll rate is above 85%. This variety has outstanding boll-setting ability, with an average of 9-10 bolls per plant, a boll weight of 6.4-6.8 grams, and an average lint percentage above 38%. In Liaoning Province, the general lint yield is 80 kg per mu, and high-yield fields can reach 120-130 kg; in **the northern Xinjiang region, diseased and poor fields generally yield 100 kg of lint per mu, and high-yield fields reach 156 kg/mu.
Liaomian 15 fiber is pure white in color with a silky luster, the main fiber length is above 29 mm, the fiber specific strength is 22 g/tex, the Micronaire value is 4.2-4.3, and the purchase rate of grade-one cotton is more than 15% higher than that of ordinary varieties. Tested by the Beijing Fiber Inspection Institute, it can be spun into yarn counts of 32-42 and is comprehensively rated as superior grade. At present, in **it has been exported to Japan and other countries as an inspection-exempt variety, and its low sugar content is especially favored by foreign buyers. This variety is highly resistant to fusarium wilt and resistant to verticillium wilt, with a fusarium wilt index of 0.51 and a verticillium wilt index of 7.45, and is relatively resistant to seedling diseases and boll diseases.
Breeder: Liaoning Academy of Agricultural Sciences
Regions and techniques: this variety is suitable for planting in lightly and heavily diseased fields in all extra-early-maturing cotton regions, the summer-sowing cotton region of the Yellow River basin, and the northwest inland cotton region. At present, it has been promoted cumulatively to 10 million mu, increasing lint cotton by 128.05 million kg, and it is expected that the cumulative promoted area will reach 15 million mu by 2000.
Cultivation procedures:
1. Sowing: follow the principle of sowing before frost and emergence after frost, with April 20-26 as the best sowing period, and no later than May 5. In cotton-growing areas with experience in early sowing and seedling preservation, the method of narrow ditching, deep ditching and shallow covering with soil can be used, leaving a certain gap between the sowing furrow and the plastic film so that the seedlings avoid frost damage and are also protected from being scalded by the plastic film. Using this method can advance the sowing period by about 10 days.
2. Density: in fields of ordinary fertility, keep about 6,500 plants per mu, with 9-10 fruiting branches per plant; in high-fertility fields, increase the row spacing, reduce the density by 10% compared with the conventional density, and retain sufficient fruiting branches and fruiting nodes. In dry and poor land, the plant density can be increased by 10%-15% compared with the conventional density, with appropriately fewer fruiting branches and fruiting nodes retained.
3. Fertilization: Liaomian 15 has strong growth vigor, and after plastic mulching its vegetative growth becomes even more vigorous, so it requires a relatively large amount of fertilizer, and the base fertilizer should be applied fully at one time. According to the target of 80-100 kg of lint yield per mu and the fertility status of the cultivated land, generally apply 3,000-4,000 kg of high-quality farmyard manure and 40-60 kg of standard nitrogen fertilizer per mu for the whole year; half of the annual nitrogen application can be deeply applied together with phosphate fertilizer as base fertilizer.
4. Chemical regulation: at the early flowering stage, spray mepiquat chloride at 2-2.5 g/mu; for vigorously growing cotton fields, use mepiquat chloride at 3-4 g/mu. Top the plants around July 10 and finish before July 15. Irrigate in a timely manner, watering 2-3 times according to drought conditions, but the last irrigation must not be later than August 10 to avoid excessive late growth.
5. Pest control: when the number of cotton bollworm eggs laid per 100 plants reaches more than 5, control should be carried out promptly, requiring "continuous support and coverage, spraying thoroughly on all sides." Control of cotton aphids can be carried out simultaneously with or alternately with control of cotton bollworm.
6. Harvest: harvest and dry the cotton in a timely manner; seed cotton for seed use must be harvested and ginned separately, and both lint and seed should be stored separately.