Abstract Information on macronutrient uptake and nutrient use efficiency (NUE) of cassava genotypes under different planting dates is limited. The aims of this study were 1) to investigate the responses of cassava genotypes to planting dates for nutrient uptake and NUE and 2) to identify the superior genotypes based on these traits. Three cassava genotypes (Kasetsart 50 (KU50), Rayong 11 (RY11) and CMR38-125-77) were planted in a randomized complete block design with four replications at four planting dates (20-Apr, 30-Jun, 5-Oct and 15-Dec 2016) and harvested at 12 months after planting (MAP). Planting cassava on 20-Apr and 15-Dec produced the highest total crop nutrient uptake and nutrient uptake for storage roots. Whereas planting cassava on 5-Oct and 15-Dec with higher solar radiation, temperature, relative humidity and longer photoperiod during canopy establishment until high carbohydrates translocation and with lower temperature and shorter photoperiod during a dormancy period resulted in greater NUE for biomass and storage roots and nutrient harvest index for all genotypes and most elements. CMR38-125-77 and KU50 showed good performance in terms of total nutrient uptake across planting dates (1.45–38.31 g plant−1) for most elements. CMR38-125-77 seems to be the best genotype on the basis of high storage root dry weight, high NUE for both biomass (90.1–1,594.6) and storage roots (39.9–927.1) and nutrient harvest index (0.14–0.58) for almost all planting dates, except in planting date 20-Apr in which RY11 was the highest for these traits. The genotype identified is useful as parental source for further breeding programs to improve genotypes with high NUE and high storage root yield.

中文翻译：

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不同种植期对不同淀粉膨化期木薯基因型养分吸收和养分利用效率的影响

摘要 关于不同种植日期木薯基因型的常量营养素吸收和养分利用效率（NUE）的信息有限。本研究的目的是 1) 调查木薯基因型对种植日期对养分吸收和 NUE 的反应，以及 2) 确定基于这些性状的优良基因型。三种木薯基因型（Kasetsart 50 (KU50)、Rayong 11 (RY11) 和 CMR38-125-77）以随机完整区组设计种植，在四个种植日期（4 月 20 日、6 月 30 日、10 月 5 日和2016 年 12 月 15 日）并在种植后 12 个月收获（MAP）。在 4 月 20 日和 12 月 15 日种植木薯产生了最高的作物总养分吸收和储存根的养分吸收。鉴于在太阳辐射较高、温度较高的 10 月 5 日和 12 月 15 日种植木薯，冠层建立期间的相对湿度和较长的光周期直到高碳水化合物易位，以及休眠期间较低的温度和较短的光周期导致生物量和储存根的更大 NUE 以及所有基因型和大多数元素的养分收获指数。对于大多数元素，CMR38-125-77 和 KU50 在整个种植日期（1.45-38.31 g 植物-1）的总养分吸收方面表现出良好的性能。CMR38-125-77 似乎是最好的基因型，因为它具有高贮藏根干重、生物量 (90.1-1,594.6) 和贮藏根 (39.9-927.1) 的高 NUE 和养分收获指数 (0.14-0.58) 几乎所有种植日期，除了种植日期 20-4 月，其中 RY11 在这些性状中最高。