不同割苗期对春玉米产量及植株性状的影响

研究春玉米不同割苗时期对产量性状、根系性状、株高、穗位高的调控效应,明确春玉米在鲁中地区最佳割苗时期。以‘莱农14’和‘登海605’为试验材料,分别在玉米4叶龄、5叶龄、6叶龄、7叶龄期进行割苗处理,以不割苗处理作对照。结果表明,2017年2个品种4叶龄期割苗较对照分别增产12.87%和9.31%,2018年分别增产11.31%和10.15%。5叶龄期割苗增产不显著,6叶龄期割苗‘莱农14’极少数长出再生苗,但很快萎糵,最后死亡;‘登海605’在6叶龄期再生苗无法抽出,7叶龄期2个品种再生苗均无法抽出。2个品种4叶龄期割苗还增加了干物质积累量、根系数量,提高了叶面积指数,降低了株高、穗位高,提高了抗倒伏性能。鲁中地区春玉米产量最高、植株性能最佳的割苗时期为4叶龄期。

Effect of Different Seedling Cutting Periods on Spring Maize Grain Yield and Plant Traits

To get the optimum cutting period, we studied the regulation effect of different seedling cutting periods on yield traits, root trait, plant height and spike height of spring-maize. Two spring-maize hybrids, ‘Lainong14’ (LN14) and ‘Denghai605’ (DH605), were selected as the experimental materials. The cutting periods of no seedling cutting (CK), and four (SC4), five (SC5), six (SC6), seven (SC7) fully expanded leaves age were set up. Results showed that the grain yield in SC4 of LN14 and DH605 increased respectively by 12.87%, 9.31% in 2017 and 11.31%, 10.15% in 2018 compared with that of CK. But the yield increase of SC5 was not significant. Very few ratooning seedlings were observed at SC6 of LN14, but quickly died. There was no ratooning seedling extraction at SC6 and SC7 of DH605 and SC7 of LN14. Shoot biomass, root numbers and leaf area index increased, plant height and spike height decreased and anti-lodging performance was improved significantly in SC4 of LN14 and DH605. Thus, the optimal seedling cutting time of spring maize to achieve high yield and high plant performance is at four fully expanded leaves age in central Shandong Province.