Introduction to the Yudou 21 Soybean Variety and Its Cultivation Points
The new soybean variety Yudou 21 was developed according to the breeding principle of selecting and pairing superior × superior parents. In 1986, the large-seeded, high-yielding, disease-resistant medium-maturity variety Yudou 10 was used as the female parent, and the multi-branched, dense-podded, high-quality, multi-resistant small-seeded variety Yudou 6 was used as the male parent. They were combined using the diallel crossing experimental method, and the variety was bred by the Institute of Industrial Crops, Henan Academy of Agricultural Sciences through 10 years and 11 generations of directional selection.
Characteristics and traits: Yudou 21 (Zhengshuangjiao 8603-1) has a growth period of 105 days and belongs to the medium-maturity variety. It has a determinate podding habit, the plant is erect, plant height around 80 cm, strong branching ability, generally 3-4 branches, and a compact plant type. Each plant has about 60 pods, with 2-3 seeds per pod. The leaf shape is elliptical and medium-sized. The young stem is green, flowers are white, and hairs and pods are gray. The seed coat is yellow, the seed is elliptical, the hilum is light brown, and leaf drop is good. The 100-seed weight is about 18 g, belonging to the small-seeded type. According to identification by the Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengshuangjiao 8603-1 is resistant to mosaic virus disease, purple spot disease, and anthracnose. In the provincial regional trials from 1992 to 1994, the annual average grade of mosaic virus disease for this variety was 0.15-0.6, and the purple spot diseased-seed rate was 0.5%-1.7%. There was no anthracnose, and all were at the resistant level. According to many years of provincial regional trials and production statistics, the average lodging degree of Zhengshuangjiao 8603-1 was 0.9, making it a lodging-resistant variety. Zhengshuangjiao 8603-1 showed high yield and good yield stability in yield trials at various levels from 1992 to 1995. It participated in a total of 59 site-trials, of which 50 site-trials showed increased yield and 9 site-trials showed decreased yield, with increased-yield site-trials accounting for 85% of the total test site-trials. On average, it increased yield by 13.8% compared with the control, mostly ranking first or second among the tested varieties. In the 1992 Henan Province preliminary trial, the average yield over 12 sites was 180.20 kg per mu, an increase of 14.90% compared with the control Yudou 2. It ranked second among the tested varieties. In the 1993 provincial regional trial, the average yield over 18 sites was 175.19 kg per mu, an increase of 14.18% compared with the control Yudou 8, ranking fourth among the tested varieties; in the two-year provincial regional trial from 1993 to 1994, the average yield over 35 sites was 178.12 kg per mu, an increase of 16.18% compared with the control Yudou 8, and the overall evaluation ranked second among the tested varieties. In the 1995 Henan Province production trial, the average yield over 12 sites was 167.3 kg per mu, an increase of 5.9% compared with the control Yudou 8.
This variety is a high-protein variety. According to the "Eighth Five-Year Plan" national soybean breeding program, a soybean protein content above 45% is considered a high-protein variety. A combined protein and fat content exceeding 63% is considered a high-quality variety. According to the 1991, 1993, and 1994 seed test analysis results for Zhengshuangjiao 8603-1 by the Chinese Academy of Agricultural Sciences and the Agricultural Product Quality Supervision and Testing Center of the Ministry of Agriculture (Zhengzhou), the protein contents were 46.38%, 47.48%, and 48.0% respectively, averaging 47.29%, which was 3.38 percentage points higher than the 43.91% of the control Ke S Yudou 8. The fat contents were 18.32%, 17.85%, and 17.24% respectively, averaging 17.8%, and the combined protein and fat content averaged 65.09% over the 3 years.
Breeder: Institute of Industrial Crops, Henan Academy of Agricultural Sciences
Region and technology: Yudou 21 is suitable for planting throughout Henan Province and in areas such as northern Jiangsu, northern Anhui, and southwestern Shandong.
Cultivation procedures:
1. Sowing time and sowing rate: The suitable sowing time is early to mid-June, with a sowing rate of 3.5-4 kg per mu. Use 0.5 m or 0.4 m equal row spacing, carry out manual thinning, with a plant spacing of 10-13.8 cm, and retain 12,000-15,000 plants per mu. For interplanting in wheat furrows, sow 10 days before wheat harvest. Use 5,000 holes per mu, retaining 2-3 plants per hole.
2. Scientific fertilization: This variety has no strict soil requirements, and shows outstanding yield increases on medium or higher fertility land; on high-water and high-fertility plots, the yield per mu can reach more than 250 kg. To achieve high yield, apply 40-50 kg of calcium magnesium phosphate fertilizer per mu, or 40 kg of diammonium. At the early flowering stage, topdress with 10-15 kg of diammonium, and foliar spraying of micronutrient fertilizer can also be used.
3. Strengthen field management: Before the soybean canopy closes, cultivate and weed 2-3 times, control insect pests in a timely manner, and irrigate during drought at the flowering and podding stage; these are also important measures for achieving high yield.