头季留茬高度对水稻再生季产量和稻米品质的影响

研究头季留茬高度对水稻再生季产量形成和稻米品质的影响,为实现再生季高产优质提供理论依据。以杂交稻新两优223和常规稻黄华占为试验材料。头季收割时设置40（高留茬,HS）、20（中留茬,MS）和5cm（低留茬,LS）3种留茬高度处理,考察不同节位再生穗产量构成因子、稻米品质、叶面积指数、氮素含量及净光合速率（P_n）等指标。结果表明,随留茬高度降低,2个品种产量均呈下降趋势,再生季HS处理产量（4.13t/hm²）比MS和LS处理分别高9.9%和16.3%。随留茬高度降低,再生季稻米碾磨品质显著下降,新两优223整精米率下降幅度显著大于黄华占,前者HS处理分别比MS和LS处理高26.8%和59.7%;随留茬高度降低,稻米外观品质显著提升,蛋白质含量下降,直链淀粉含量无显著变化。再生季水稻主茎、叶片和新芽的氮素含量与产量呈显著正相关,HS和MS处理的P_n显著高于LS处理。综上所述,根据品种特性,调节头季收割留茬高度,可促进水稻再生季产量和品质协同提高。

Effects of Main Season Stubble Height on Ratoon Season Yield and Rice Quality

The effects of stubble height in the main season on yield formation and rice quality of the ratoon season were studied to provide theoretical basis for achieving high yield and quality in the ratoon season. Hybrid rice Xinliangyou 223 and conventional rice Huanghuazhan were used as experimental materials. Three stubble heights, 40(high stubble, HS), 20 (middle stubble, MS) and 5cm (low stubble, LS) were designed in main season, and components of different nodes yield, ratoon season rice quality, leaf area index, nitrogen content, net photosynthetic rate (P_n) in ratoon season were studied. The results showed that the yield of the two cultivars decreased with the decrease of stubble height, and the yield of HS treatment (4.13t/ha) was 9.9% and 16.3% higher than that of MS and LS treatments. With the decrease of stubble height, the milling quality of ratooning rice was significantly decreased, and the head rice rate of Xinliangyou 223 was significantly decreased than that of Huanghuazhan. The HS treatment of Xinliangyou 223 was 26.8% and 59.7% higher than that of MS and LS treatments, respectively. With the decrease of stubble height, appearance quality of rice was significantly improved, protein contents decreased, and amylose contents had no significant change. Nitrogen contents of main stems, leaves and new buds in ratoon season were significantly positively correlated with yield, and P_n of HS and MS treatments were significantly higher than that of LS treatment. In conclusion, according to the characteristics of varieties, the stubble height in the main season should be adjusted to promote the synergistic improvement of yield and quality in the ratoon season.