Departamento de Producción Animal, Facultad de Agronomía, Universidad de Concepción, Concepción, Chile.
Facultad de Agronomía, Universidad de Concepción, Concepción, Chile.
PLoS One. 2024 Sep 6;19(9):e0310009. doi: 10.1371/journal.pone.0310009. eCollection 2024.
Traditional pastures in temperate regions face limitations such as reduced growth and nutritional quality during the summer season. Plantain (P. lanceolata L.) offers advantages like increased yield and decreased nitrogen losses from grazing ruminants. Effective grazing management is essential for pasture health, and defoliation frequency and intensity play a pivotal role. This study aimed to evaluate plantain's regrowth, yield, and morpho-physiological and chemical responses under different defoliation frequencies and intensities, with the goal of enhancing its management in pastures. The study was conducted in pots within a controlled-environment growth chamber, examining the impact of three defoliation frequencies (based on extended leaf length: 15, 25 and 35 cm) and two defoliation intensities (5 and 8 cm of residual heights) with four replicates (24 pots as experimental units). The variables of interest were morphological characteristics, dry matter (DM) accumulation, herbage chemical composition, growth rate traits, and photosynthetic parameters. Defoliation frequency affected plantain's growth and nutritional composition. More frequent cuts (15 cm) resulted in lower DM yield per cut and lower stem content, while less frequent cuts (35 cm) produced higher values. Defoliation intensity influenced the proportion of leaves and stems in the total DM, with 5 cm cuts favoring leaves. Nutrient content was also affected by defoliation frequency, with less frequent cuts (35 cm) showing lower crude protein concentration and metabolizable energy content but higher neutral detergent fiber and water-soluble carbohydrate concentration. Plantain's growth rate variables were mainly influenced by defoliation frequency, with less frequent cuts promoting faster leaf appearance and growth of new leaves. The basal fluorescence variables and chlorophyll content were affected by cutting frequency, being highest when cut less frequently (35 cm), while no differences were found in the actual quantum efficiency among different defoliation frequencies and intensities. The fraction of light dedicated to non-photochemical quenching was highest when cut less frequently and more intensively. Overall, defoliation at 25 cm of extended leaf length balanced plantain forage quality and regrowth capacity.
传统的温带牧场在夏季会面临生长和营养质量下降等限制。芭蕉（P. lanceolata L.）具有增加产量和减少放牧反刍动物氮损失的优势。有效的放牧管理对于牧场健康至关重要，而刈割频率和强度起着关键作用。本研究旨在评估不同刈割频率和强度下芭蕉的再生、产量以及形态生理和化学响应，以提高其在牧场上的管理水平。该研究在受控环境生长室中的盆中进行，研究了三种刈割频率（基于延长的叶片长度：15、25 和 35 cm）和两种刈割强度（5 和 8 cm 的残留高度）对芭蕉的影响，每个处理有四个重复（24 个盆作为实验单位）。感兴趣的变量包括形态特征、干物质（DM）积累、草料化学组成、生长率特性和光合参数。刈割频率影响芭蕉的生长和营养组成。更频繁的刈割（15 cm）导致每割次 DM 产量和茎含量降低，而较少的刈割（35 cm）则产生更高的值。刈割强度影响总 DM 中叶片和茎的比例，5 cm 刈割有利于叶片。养分含量也受到刈割频率的影响，较少的刈割（35 cm）表现出较低的粗蛋白浓度和可代谢能含量，但较高的中性洗涤剂纤维和水溶性碳水化合物浓度。芭蕉的生长率变量主要受刈割频率影响，较少的刈割促进叶片更快出现和新叶生长。基础荧光变量和叶绿素含量受刈割频率影响，在较少的刈割（35 cm）时最高，而不同刈割频率和强度之间的实际量子效率没有差异。用于非光化学猝灭的光部分在较少和更频繁的刈割时最高。总的来说，在延长叶片长度为 25 cm 时刈割可以平衡芭蕉饲料的质量和再生能力。
