Weed interference in Marandu palisade grass pastures under renewal or maintenance conditions

ABSTRACT The presence of weeds as a consequence of pasture degradation is one of the main problems facing livestock worldwide. Thus, knowing the interference aspects and the appropriate time for weed management is essential for applying a particular control measure. This research aimed to study the weed interference on the morphostructural and nutritional quality of the Marandu palisade grass in conditions of renewal or maintenance of pasture. The experiments were conducted in a randomized block design, with four replicates and treatments consisted of eight growth periods of coexistence between Marandu palisade grass and weeds (0, 15, 30, 45, 60, 75, 90, and 120 days). Forage grass was characterized at the end of the experimental period, corresponding to 120 days of coexistence, and the main morphostructural and nutritional components were determined. Under the renewal or maintenance process, the weeds interfere in the morphostructural and nutritional quality of pasture areas with Marandu palisade grass. In vitro organic matter digestibility of Marandu palisade grass is negatively influenced by weeds, suggesting that control measures for renewal or maintenance areas should be adopted within 24 and 18 days of coexistence, respectively.

摘要：牧场退化引发的杂草滋生，是全球畜牧业面临的核心难题之一。明确杂草的干扰特性与杂草防控的适宜时机，是落实针对性防除措施的关键前提。本研究旨在探究牧场更新或维持阶段中，杂草对马兰多臂形草（Marandu palisade grass）形态结构与营养品质的干扰效应。实验采用随机区组设计，设置4次重复，处理组包含8个马兰多臂形草与杂草的共生时长梯度（0、15、30、45、60、75、90及120天）。于共生120天的实验结束节点对供试牧草进行性状表征，并测定其核心形态结构与营养组分。结果显示，在牧场更新或维持流程中，杂草会对种植马兰多臂形草的牧场区域的形态结构与营养品质产生干扰；马兰多臂形草的体外有机物消化率会受到杂草的负面影响，提示针对牧场更新区与维持区的杂草防控措施，应分别在共生24天与18天内启动实施。