不同播期与播量配置对北疆滴灌冬小麦群体结构及干物质动态积累的影响OA

The study investigated the effects of sowing date and seeding rate on the population struc-ture and yield of winter wheat under drip irrigation in Xinjiang,and identified appropriate seeding rates for different sowing dates,providing a theoretical basis for wheat production practices in Xinjiang.Using'Shidong 0358'as the test material,a two-factor split-plot experimental design was adopted,with sowing date as the main plot,including September 24 as the appropriate sowing date(S)and Oc-tober 29 as the late sowing date(W),and sowing rate as the subplot.Under optimal sowing,five see-ding rates were set:M1(6.00×106 seeds·hm-2),M2(6.75×106 seeds·hm-2),M3(7.50×106 seeds·hm-2),M4(8.25×106 seeds·hm-2),and M5(9.00×106 seeds·hm-2).Under late sowing,an additional treatment,M6(9.75×106 seeds·hm-2),was included on the basis of the optimal so-wing treatments.,The results showed that the number of tillers of drip-irrigated winter wheat de-creased with the delayed sowing but increased with increasing seeding rate.Within the measurement period,the tiller number reached its maximum at the highest seeding rate.Delayed sowing resulted in a significant decline in leaf area at each leaf position.When the seeding rate exceeded 6.75×106 seeds·hm-2(M2)under the appropriate sowing condition or exceeded 6.00×106 seeds·hm-2(M1)under the late sowing condition,leaf area decreased.At the same seeding rate,delayed sowing significantly reduced dry matter accumulation,pre-anthesis translocation,post-anthesis accumulation,and their con-tribution to grain yield.Under the same sowing date,moderate increases in seeding rate promoted dry matter accumulation and translocation,whereas excessive seeding resulted in a decline.The highest dry matter accumulation was observed in M5 under late sowing and in M3 under appropriate sowing condi-tions.Under late sowing,grain yield of M5 reached 7 328.73 kg·hm-2,representing an increase of 4.26%-14.74%compared with other treatments.Under appropriate sowing conditions,M3 produced the highest yield of 8 542.78 kg·hm-2,with an increase of 2.15%-10.23%.Based on the experi-mental results,the recommended seeding rate ranged from M5 to M6(9.00×106-9.75×106 seeds·hm-2)under late sowing and from M2 to M3(6.75×106-7.50×106 seeds·hm-2)under appropri-ate sowing,at which maximum yield was achieved.