不同降水年型下旱地玉米产量性状对种植密度和品种的响应

Responses of yield traits to planting density and cultivar of spring maize in drylands under different rainfall types

旱地玉米生产受降水分布影响,产量在不同降水年型之间波动较大。为探究种植密度和品种对不同降水年型旱地玉米产量性状的影响,设置4个密度(52500、67500、82500和97500株/hm^(2))处理,以豫玉22、郑单958和先玉335为供试品种,于2013—2018年连续定位测定收获期产量性状。结果表明,旱地玉米穗长和穗粗随种植密度增加而下降,秃尖长则呈上升趋势。不同降水年型,穗长、穗粗差异显著(P<0.05),总体表现为丰水年≥平水年>干旱年,秃尖长则呈相反变化趋势。降水年型显著影响旱地玉米产量,平水年和丰水年显著高于干旱年(P<0.05),且平水年和丰水年产量稳定性更高。种植密度显著影响玉米产量性状,单位面积穗数与种植密度呈显著正相关关系(P<0.05),而穗粒数和千粒质量与密度呈显著负相关(P<0.05)。种植密度和品种类型对产量的影响达到显著水平(P<0.05),但不同品种产量对密度的响应不同,豫玉22适宜种植密度为52500~67500株/hm^(2),郑单958和先玉335适宜密度范围为67500~82500株/hm^(2),且郑单958和先玉335产量稳定性更高。相关性分析表明,在干旱年,无论在任何密度条件下,单位面积穗数和穗粒数是影响产量的最主要因素;在平水年和丰水年,低密度(52500株/hm^(2))条件下单位面积穗数是影响产量的主要因素,而在高密度(97500株/hm^(2))条件下,百粒质量是影响产量的主要因素。综上所述,从产量效益的角度考虑,较高种植密度(67500~82500株/hm^(2))结合耐密品种(郑单958和先玉335)是适宜于旱地玉米的最佳种植模式。该研究结果可为旱地有限降水的高效利用和玉米高产稳产提供理论依据。

A maize yield can depend greatly on the rainfall types in dryland agriculture.This study aims to investigate the effects of planting density on the yield traits of spring maize under different rainfall types in dryland.A successive field experiment was also carried out for the planting density of spring maize from different cultivars in the dryland farming experimental station of Northwest A&F University in Heyang County,Shaanxi Province of China from 2013 to 2018.Taking the Yuyu22,Zhengdan958,and Xianyu335 as the experimental cultivars,four planting densities were set(D1:52500,D2:67500,D3:82500,and D4:97500 plant/hm^(2))to determine the yield traits at the harvest stage in each growing season.The results showed that the ear length and ear diameter of maize decreased with the increase of planting density,whereas,the length of tip back was on the rise.There were significant differences in the ear length and ear diameter among different rainfall types(P<0.05),where the overall performance was also ranked in the order of the wet year≥normal year>dry year,but the order of the length of tip back was the dry year>normal year≥wet year.The rainfall types posed significant effects on the yield traits,further to determine the grain yield of maize in dryland,indicating that the yield in the normal and wet years was significantly higher than that in the dry years(P<0.05),whereas,the yield stability was also higher in the normal and wet years than that of dry years.Furthermore,there were significant positive correlations of planting density on the ear number per square(P<0.05),whereas,the kernel number per ear and 100-seed weight presented a negative correlation with the planting density(P<0.05).The planting density and cultivar posed a significant influence on the grain yield,but the cultivars greatly varied in response to the planting density(P<0.05).Specifically,the suitable planting density of Yuyu22 was 52500-67500 plant//hm^(2),and Zhengdan958 and Xianyu335 were 67500-82500 plant/hm^(2).Moreover,the latter presented a more stable yield.The correlation analysis showed that the ears number per square and the number of the kernels per ear were the most important factors affecting the yield of spring maize in the dry years.In the normal and wet years,the ear number per square was the main factor under a low planting density(D1),whereas,the 100-seed weight of spring maize served as the main factor under a high planting density(D4).A relatively higher planting density with 67500-82500 plant/hm^(2) combined with the density-tolerance cultivar(Zhengdan958 and Xianyu335)can be widely expected to improve the grain yield and yield stability of dryland maize.The finding can provide for the optimal planting pattern in sustainable dryland agriculture.