STRUCTURAL AND PRODUCTIVE CHARACTERISTICS IN INTRASPECIFIC AND INTERSPECIFIC HYBRIDS OF ELEPHANTGRASS

Abstract The objective of this study was to evaluate the structure and forage production of hybrids of elephant-grass managed under cut. Twenty-four clones of elephant-grass from Embrapa dairy cattle were used as treatments, and Cameroom as a control. The grasses were cut close to the ground, every 60 days. The parameters evaluated were yield and dry matter content, number of basal tillers, number of leaves per tiller, plant height, stem diameter. The highest height of the plants was observed in clone CNPGL 00-103-1. The group with the highest number of tillers had three clones and a mean of 39.38 tiller m-2. In the group of clones CNPGL 00-103-1, CNPGL 93-25-3, CNPGL 00-16-1 and CNPGL 00-90-3 the highest dry matter contents (22.7% DM) were observed. The highest masses of forage, leaf blade and stem were observed in clone CNPGL 00-214, 15852 and 6195 kg ha-1 DM, respectively. The highest leaf blade / stem ratio was of the CNPGL 00-201-1 clone, and only in this did the leaf blade mass exceed that of the stem. Clone CNPGL 00-214 showed to be more productive, with high tillering capacity and forage accumulation.

摘要 本研究旨在评估刈割管理下象草杂交种的结构特征与饲草产量。试验采用巴西农业研究公司（Embrapa）乳牛研究中心的24个象草无性系作为供试材料，以Cameroom作为对照品种。供试草种每60天贴近地面刈割一次，测定指标包括产量与干物质（dry matter, DM）含量、基部分蘖数、单株分蘖叶片数、株高及茎粗。株高最高的无性系为CNPGL 00-103-1。分蘖数最多的组包含3个无性系，平均分蘖数为39.38个·m⁻²。在CNPGL 00-103-1、CNPGL 93-25-3、CNPGL 00-16-1及CNPGL 00-90-3这几个无性系中，测得最高干物质含量（22.7% DM）。饲草、叶片及茎秆干物质产量最高的无性系为CNPGL 00-214，其相关产量分别达15852 kg·ha⁻¹ DM与6195 kg·ha⁻¹ DM。叶茎比最高的无性系为CNPGL 00-201-1，且仅该无性系的叶片干重超过茎秆干重。无性系CNPGL 00-214表现出最优生产性能，兼具较强的分蘖能力与饲草积累能力。