Rice (Oryza sativa L.) yield and grain quality are highly influenced by the planting date; thus, it is crucial to determine the optimal planting window for an area of cultivation. In this study, date of planting experiments conducted at the Louisiana State University (LSU) AgCenter Rice Research Station from 2011 to 2018 were analyzed to quantify the effect of planting date, genotype, and year on key agronomic traits. Planting date was strongly associated with yield across every year, explaining 55.6% of the overall phenotypic variation. A clear relationship was observed between later plantings and reduced yields; and the highest yields were observed during plantings between 11 and 31 March. Rice planted after the optimal planting window displays a yield reduction following a cubic regression trend. Planting date was associated with milling yield, explaining 28.6% of the phenotypic variation, however the effect size varied year to year. Milling yields were highest with the early and late planting dates, while reduced milling yields were observed in plantings between mid‐April and early June. Days to heading and days to seedling emergence were strongly associated with planting date; with planting date explaining, on average, 86 and 96% of the variation, respectively. Plant height was less influenced by planting date, with genotype being the largest source of variation. The results from this study highlight the importance of choosing the optimal planting date and identifies an optimal planting window to maximize grain and milling yield for Southwest Louisiana.

中文翻译：

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路易斯安那西南部水稻播种日期和最佳播种期的影响

水稻（水稻L.）产量和谷物质量受种植日期的影响很大；因此，至关重要的是确定一个耕种区域的最佳种植窗口。在这项研究中，分析了路易斯安那州立大学（LSU）AgCenter水稻研究站从2011年至2018年进行的播种试验日期，以量化播种日期，基因型和年份对关键农艺性状的影响。播种日期与每年的产量密切相关，解释了全部表型变异的55.6％。后来的播种与减产之间存在明显的关系。在3月11日至31日的播种期间，单产最高。在最佳种植窗口之后种植的水稻随着三次回归趋势显示出单产下降。播种日期与制粉量有关，解释为28。表型变异的6％，但是效应大小逐年变化。在播种的早期和后期，碾米产量最高，而在4月中旬至6月初的播种中，碾米产量下降。抽穗期和出苗天数与播种日期密切相关。播种日期分别平均解释了该变化的86％和96％。株高不受种植日期的影响，基因型是最大的变异来源。这项研究的结果突出了选择最佳播种日期的重要性，并确定了最佳播种窗口，以最大限度地提高西南路易斯安那州的谷物和制粉产量。而在4月中旬至6月初之间的播种中发现制粉产量下降。抽穗期和出苗天数与播种日期密切相关。播种日期分别平均解释了该变化的86％和96％。株高不受种植日期的影响，基因型是最大的变异来源。这项研究的结果突出了选择最佳播种日期的重要性，并确定了最佳播种窗口，以最大限度地提高西南路易斯安那州的谷物和制粉产量。而在4月中旬至6月初之间的播种中发现制粉产量下降。抽穗期和出苗天数与播种日期密切相关。播种日期分别平均解释了该变化的86％和96％。株高不受种植日期的影响，基因型是最大的变异来源。这项研究的结果突出了选择最佳播种日期的重要性，并确定了最佳播种窗口，以最大限度地提高西南路易斯安那州的谷物和制粉产量。株高不受种植日期的影响，基因型是最大的变异来源。这项研究的结果突出了选择最佳播种日期的重要性，并确定了最佳播种窗口，以最大限度地提高西南路易斯安那州的谷物和制粉产量。株高不受种植日期的影响，基因型是最大的变异来源。这项研究的结果突出了选择最佳播种日期的重要性，并确定了最佳播种窗口，以最大限度地提高西南路易斯安那州的谷物和制粉产量。