Rhizoma peanut (RP; Arachis glabrata Benth.) is an important species for hay production in the U.S. Gulf Coast region; however, frequent summer rains and high humidity often preclude optimal harvest intervals. Extended regrowth periods are common on‐farm but data are limited assessing their impact on plant responses. The objective was to compare above‐ and belowground responses of 14 RP entries to defoliation frequency during 3 yr. Frequencies were one (1×) and two (2×) harvests per year, reflecting common producer practice. Annual herbage accumulation (HA) was approximately twice as great for 2× than 1× (10.5 vs. 5.4 Mg ha⁻¹ yr⁻¹, respectively). An exception was experimental line Beta for which HA did not differ between frequencies, perhaps because of Beta's greater disease tolerance that minimized leaf shedding. The 2× frequency also had greater herbage crude protein concentration than 1× (150 and 125 g kg⁻¹, respectively). Reductions in HA and nutritive value for 1× vs. 2× were generally greatest for upright‐growing entries. Plots cut once per year had 54% more root–rhizome mass than those cut twice (8.5 vs 5.5 Mg ha⁻¹, respectively) but defoliation frequency did not affect root–rhizome total nonstructural carbohydrate (TNC) concentration. Results indicated RP hay producers should harvest both summer and fall (2×) at minimum. If rhizomes are to be dug for subsequent vegetative propagation, defoliation should be limited to once annually to avoid reduction in root–rhizome mass.

中文翻译：

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花生根茎和根茎对长生期的响应

花生根茎（RP；花生）是美国墨西哥湾沿岸地区重要的干草生产品种。但是，夏季的频繁降雨和高湿度通常会妨碍最佳的收获间隔。延长农作物的再生期很常见，但评估其对植物反应的影响的数据有限。目的是比较3年期间14个RP条目对地上和地下对落叶频率的响应。每年的收获频率为一（1x）和两（2x），反映了生产者的普遍习惯。2×的年度牧草累积量（HA）约为1×的两倍（10.5 vs. 5.4 Mg ha ^-1 yr ^-1， 分别）。一个例外是试验品系Beta，其HA在频率之间没有差异，这可能是因为Beta具有更高的抗病性，从而最大程度地减少了叶片脱落。2倍频率也比1倍（分别为150和125 g kg ^-1）具有更高的牧草粗蛋白浓度。通常，对于直立生长的动物，HA和营养价值的降低分别是1倍和2倍。每年砍伐一次的地块根茎质量比砍伐两次的地块多54％（8.5 vs 5.5 Mg ha ^-1，分别），但去叶频率并不影响根茎总非结构性碳水化合物（TNC）的浓度。结果表明，RP干草生产者应至少在夏季和秋季收获（2倍）。如果要挖根茎以进行随后的营养繁殖，应每年进行一次脱叶，以避免根茎质量下降。