通过大田不同播期试验,研究播期间气性因素差异对不同品种玉米果穗建成的影响。结果表明,双穗率对穗数具有显著的间接负效应,空秆率对穗数具有显著的直接负效应,另外果穗分蘖率是影响空秆率的重要因素。播期对果穗建成因素的影响均达显著或极显著水平,品种间穗数无差异但双穗率和空秆率差异显著。出苗至拔节阶段日温差越高和适当降雨,双穗率和空秆率越低,穗数越多；出苗至拔节和拔节至大口期内高温危害,以及拔节至吐丝期夜温升高、日温差变小和渍涝胁迫,均显著提高了双穗率和空秆率；另外吐丝后14 d内高温天数导致花丝受精率降低或者受精花丝籽粒败育,降低穗数。通过调整播期,调控玉米果穗建成期气象因素是构建高产多穗群体的技术手段之一.
英文摘要:
Field experiment using three maize hybrid was conducted by 10 sowing date (SD) to study the effects of different meteorological factors response to SD, on maize ear establishments. The results showed that double ear rate (DER) had significantly negative indirect effects on ear number (EN), while bare plant rate (BPR) which was effected by ear tiller rate were significantly and negatively direct affected on EN. EN, BER and BPR were significant different by SD delayed, meanwhile EN had no significant different belong to maize hybrids, however, different hybrids abtained significantly different DER and BPR. The higher mean diurnal temperature range (M△T) and optimized precipitation during VE-V6 interval redued DER and BPR, and increased EN. DER and BPR were significantly increased due to the higher maximum temperature during VE-V6 and V6-V12, the minimum temperature increasing, M△T decreasing, and flooding stress with higher precipitation during V6-V12 and V12-R1 interval. The days of maximum temperature higher than 34 ℃ in 14 d after silking may leded lower fertilization rate or kernels abortion, increased BPR and decreased EN. So, adjust sowing date to obtained the optimized meteorological condition for maize ear formation is one of the cultivation techniques to grain higher yield by more ear number.
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