Abstract:

To achieve a high yield of adzuki bean, a field split-plot design with sowing date (T1:16 ^th June, T2:23 ^th June, T3:30 ^th June, T4:7 ^th July, T5:14 ^th July) as the main plot and density (×10 ⁴ plants/hm ²) (D1:8.0, D2:10.0, D3:12.0 and D4:14.0) as the subplot, was used to explore the effects of sowing date and planting density on yield and related traits of Dehong 5261, a new erect variety. The results showed that with the delay of sowing date, the plant height, pitch number of main stem, branch number of main stem as well as pods per plant all gradually decreased. Seeds per pod and hundred-seed weight decreased only with the growing planting density and sowing too early or too late all had disadvantage for their increases. Population grain yield and single plant yield were significantly affected by the sowing date as well as the interactive effects of sowing date and planting density, and they both decreased by the delay of sowing date. The yield per plant significantly declined as the planting density increased while the population grain yield initially rose and then declined. The influence factor was sequenced as sowing date (F=421.98) > interaction of sowing date and planting density (F=37.55) > planting density (F=2.10) for population grain yield and planting density (F=425.74) > sowing date (F=369.20) > interaction of sowing date and planting density (F=44.23) for single yield. A regression equation was established with the sowing date (X₁), the planting density (X₂) and grain yield (Y): Y=2659.46–60.63X₁+14.60X₂+0.05117X₁ ²–2.94X₂ ²+3.54X₁X₂ (R ²=8833). The results showed that the optimum density for sowing was 8.0×10 ⁴plants/hm ² from 16 ^th June to 22 ^th June, 9.0×10 ⁴ plants/hm ² from 23 ^th June to 29 ^th June, 13.0×10 ⁴ plants/hm ² from 30 ^th June to 6 ^th July and 14.0×10 ⁴ plants/hm ² from 7 ^th July to 14 ^th July.

Key words: Adzuki bean, Sowing date, Planting density, Yield, Related traits