Effects of different sowing dates on the growth and yield of soybean

1 tested varieties

(1) early hairy beans: big grain king, early white bird, Ningshu 60. (2) Summer beans: Yudou 16, Huaidou 4, Nannong 242, Nannong 86-4, Nannong 88-31, Nannong 96CT-1. (3) Special beans: Dan Bosnia and Herzegovina, Japan 118, Haimen Green, Marine 13, Black skin and Green Kernel, Green Pearl. (4) legumes for sprouting: 98-29pr 98-30pr Smur03. Among the above 18 varieties (lines), Zaosheng White Bird and Ning vegetable 60 were introduced from Jiangsu Academy of Agricultural Sciences, Nannong series were introduced from Nanjing Agricultural University, Dazhiwang, Yudou 16 and Huaidou 4 were purchased from the local seed market, and the others were quoted from the Institute of Agricultural Sciences along the Yangtze River in Jiangsu Province.

2 test method

Each variety (line) has three sowing periods of June 16, July 1 and July 16 (hereinafter referred to as early, middle and late sowing respectively). The sowing rows of 5m long and 4 rows in each plot are set and repeated once. The row spacing of sowing holes was 25cm, the row spacing of early hairy beans was 45cm, and the row spacing of other varieties was 60 cm. 4 seeds were sowed in each hole, and 2 seedlings were set in each hole. After the seedlings were fixed, 10 plants were marked for each variety, and the dynamics of growth and development were investigated regularly. The plant characters and yield structure were investigated in the middle two rows at maturity.

3 test results

3.1 effects of different sowing dates on the growth period of soybean. The growth periods of early hairy bean, summer soybean, special bean and bud bean were 86-109, 85-118, 100-141 and 95-125 days, respectively, and the harvest period of green pods appeared at 50-66, 60-88, 69-98 and 79-105 days after sowing, respectively. There was no obvious regular difference among early soybean varieties and sowing dates, and the whole growth period of other soybean varieties shortened with the delay of sowing time.

3.2 effects of different sowing dates on the growth characteristics of soybean. The plant height of early mildew bean, summer soybean, special bean and bud bean was 34-46, 37-100,47-97 and 70-134cm respectively, and the number of branches per plant was 2-4,1.7-10,2.7-7.5,2-9.6, respectively. The plant height and branch number of different varieties decreased with the postponement of sowing date.

3.3 effects of different sowing dates on yield structure of soybean. The 100-grain weights of early edamame bean, summer soybean, special bean and bud bean were about 23, 22, 30-55 and 10-13 g, respectively. The number of effective pods per plant was 12-20, 30-85, 19-54 and 50-182 respectively, the number of seeds per pod was 1.75, 1.70, 1.5-2 and 2-2.5 respectively, and the yield per plant was 5-7.8, 12-30, 20-30 and 10-28 g, respectively. Except for 100-grain weight, other yield structure indexes of the same variety decreased with the delay of sowing time.

4 discussion

There was no significant change in 100-grain weight of the same soybean variety at different sowing dates, which showed the stability of grain weight of the same soybean variety. Except for early sowing bean, the plant height, number of branches per plant, number of pods per plant and yield per plant decreased with the delay of sowing date. Therefore, in order to obtain higher soybean yield, the suitable sowing date of early soybean, summer soybean and bud soybean should be controlled before the end of June in Suzhong area of Jiangsu Province. among them, the sowing date of Nannong series and special soybean varieties should be controlled before June 20.