播期对豫南地区粳稻稻米品质的影响

Effects of Sowing Date on Japonica Rice Quality in South Henan

以5个粳稻品种为供试材料,采用分期播种的方法,设4月25日(Ⅰ)、5月10日(Ⅱ)、5月25日(Ⅲ)、6月9日(Ⅳ)、6月24日(Ⅴ)5个播期,探讨了豫南地区粳稻适宜播种期及其对稻米品质的影响。结果表明,随着播种期的推迟,供试5个品种的糙米率、精米率总体上呈现增加的趋势,而垩白度、垩白粒率以及垩白大小呈现明显的降低趋势;粒长和长宽比在不同播种期下的变异较小;各品种的胶稠度在不同播种期下基本上是以第Ⅱ期或第Ⅲ期的最大;直链淀粉含量和碱消值在不同播种期下虽然差异较大,但无明显的变化规律。模糊概率法综合评价结果显示,各品种稻米品质的综合表现均是随着播种期的推迟表现出提升的趋势,均是以第Ⅳ期或第Ⅴ期的模糊概率最高,说明在豫南地区,适当推迟播种期有利于提升稻米的综合品质。

Based on the experiment with 5 japonica varieties and 5 sowing dates,the appropriate sowing date of japonica rice in south Henan was discussed by the rice quality. The results showed that as the sowing date was postponed,the percentage of brown rice,milled rice rate of 5 japonica varieties showed an increase trend,but the chalkiness,chalky rate and chalkiness size showed a significant decrease trend.The coefficients of variation of grain length and length-width ratio were small,gel consistence of 5 japonica varieties of the second（ May 10） or the third（ May 25） sowing date was the maximum value. The amylose content and alkali spreading value of different sowing dates made a great difference,but there was no significant regular change. The result of fuzzy probability method showed that the rice quality of 5japonica varieties was increased as the sowing date postponed,and the rice quality of the fourth（ June 9）or fifth（ June 24） sowing date was the best,indicating that appropriately postponing the sowing date was beneficial for the improvement of rice quality.