不同播期和密度对紫苏生长发育和产量的影响OA

To determine the optimal sowing date and planting density for perilla(Perilla frutescens)in Xinzhou City,Shanxi Province,a field experiment was conducted in 2024 using the cultivar'Jisu 1'(Perilla frutescens).A split-plot experimental design was adopted.The main plots comprised three sowing dates:S1(May 6),S2(May 25),and S3(June 16).The subplots comprised three planting densi-ties:D1(30 000 plants·hm-2),D2(45 000 plants·hm-2),and D3(60 000 plants·hm-2).The effects of sowing date and density on growth progression,agronomic traits,dry matter accumulation,and yield were investigated.The results showed that sowing date was the domi-nant factor regulating the growth period.Delaying sowing significantly shortened the total growth duration from 131-132 days to 102-103 days,a reduction of approximately 29 days,while planting density had no significant effect on phenological stages.Delayed sowing markedly reduced plant height,stem diameter,branch number,and per-plant dry matter accumulation.Increased density exacerbated plant etiolation(height increase)but significantly suppressed stem diameter,branch number,and per-plant dry matter accumulation.The interaction between sowing date and density had significant or highly significant effects on stem diameter,branch number,and population dry matter accumulation.Regarding yield components,under S1 and S2,yield first increased and then decreased with in-creasing density,with the highest yield recorded at D2(759.05 kg·hm-2 and 731.25 kg·hm-2,respectively).Correlation analysis re-vealed that yield was highly significantly and positively correlated with plant height,branch number,stem diameter,and 1 000-grain weight,while excessive population density suppressed individual ear development.Overall,for perilla cultivation in Xinzhou City,Shanxi Province,sowing should be arranged in May,with a recommended planting density of 45 000 plants·hm-2.