Detailed introduction to the soybean variety Nandou 99

(1) Variety origin: A superior mutant plant (original code 92001-03) selected in 1989 by the Nanchong Municipal Institute of Agricultural Sciences from Aijiaozao, which was introduced from the Crop Research Institute of the Sichuan Academy of Agricultural Sciences and was bred by the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences.

(2) Characteristics and traits: plant height about 60 cm, whole growth period 113 days. Main stem 13.4 nodes, branches 2.2-3.7, leaves lanceolate, medium-sized, dark green. Purple flowers, gray pubescence, determinate podding habit. Dense podding, 78.3 pods per plant, pods evenly set from top to bottom, 1.9 seeds per pod. Pods grayish brown, first pod height 12 cm, seeds oval, seed coat yellow, glossy, hilum light yellow, 100-seed weight 21.4 g, sound seed rate 98.9%. Tested by the Provincial Academy of Agricultural Sciences in 1999, the seeds contained 43.1% protein and 21.8% crude fat. Field observations showed susceptibility to virus disease at grade 0.3 and lodging degree at grade 0.3.

(3) Yield performance: In the two-year provincial regional trial from 1997 to 1998, the average yield at 11 sites was 181.6 k9 per mu, an increase of 10.8% over the control Xidou 3; in the 1998 production trial, the average yield at 3 sites was 179.7 k9 per mu, an increase of 19.8% over the control Xidou 3.

(4) Cultivation points: ⑦ Sowing period: spring sowing in early to mid-April, summer sowing in mid-to-late May, autumn sowing from July 10 to August 5. ② Density: for spring and summer sowing as a sole crop, 12,000-14,000 plants per mu; for autumn sowing as a sole crop, 24,000-26,000 plants per mu. When intercropped with sweet potato or peanut, 5,000-7,000 plants per mu. ③ Fertilization: apply a heavy base fertilizer, and apply an early seedling-promoting fertilizer according to seedling condition; use 25-30 kg of superphosphate or human and livestock manure as the base fertilizer. ④ Field management: during the seedling stage of spring sowing, pay attention to controlling cutworms; during the seedling stage of autumn sowing, pay attention to controlling leaf-feeding pests such as crickets and caterpillars. ⑤ Harvest in time to ensure seed quality.

(5) Suitable planting areas: suitable for soybean production areas throughout the province, grown as a sole crop, intercropped, or relay intercropped.