Agronomic evaluation of Paspalum notatum Flügge under the influence of photoperiod

ABSTRACT The objective of this study was to evaluate the influence of photoperiod on the forage yield by ecotypes and intraspecific hybrids of P. notatum. Tetraploid ecotypes from the United States Department of Agriculture and the National University of the Northeast in Argentina, in addition to six intraspecific hybrids, totaling 19 ecotypes, were assessed. The materials evaluated were subjected to an extended photoperiod (14 h of light) and natural photoperiod from July 2011 to October 2012. The experimental design was a completely randomized factorial scheme of 19 × 2 (ecotypes × photoperiod) consisting of five replicates. The materials were influenced differentially by the variation in photoperiod, with one group showing high sensitivity, whereas another, smaller group, was insensitive to this factor. The use of materials with differentiated responses to photoperiod in different climatic regions can be an important tool to increase forage yield of Paspalum notatum.

摘要 本研究旨在评估光周期（photoperiod）对百喜草（Paspalum notatum）不同生态型及种内杂交种牧草产量的影响。试验共评估19份供试材料：包括来自美国农业部（United States Department of Agriculture）与阿根廷东北国立大学的四倍体生态型，以及6个种内杂交种。供试材料于2011年7月至2012年10月期间，分别接受延长光周期处理（光照时长14 h）与自然光周期处理。试验采用完全随机析因设计，因子组合为19（生态型）×2（光周期），设置5次重复。结果显示，供试材料对光周期变化的响应存在显著分化：一类群体表现出高光周期敏感性，而另一类规模较小的群体则对该因素不敏感。在不同气候区域选用对光周期响应存在分化的材料，可作为提升百喜草牧草产量的重要策略。