ABSTRACT

Given the need to minimise the environmental impact of synthetic agrochemicals in agroecosystems and to increase the sustainability of production systems, it is necessary to identify alternative methods for weed management and crop protection. Regular pruning of evergreen trees, including Ficus retusa L., can provide large quantities of leaf litter and this study aimed to evaluate the use of this leaf residue in a horticultural production system. The effects of using the residue as an organic soil amendment were assessed, including the potential of the residue to control weeds in green beans (Phaseolus vulgaris) crop. Three application rates of F. retusa leaf residue (250, 500 and 1000 g m⁻²) were applied to the soil at two locations. At both sites, the treatments significantly reduced the density and the biomass of several weed species in a dose- and weed species-dependent manner. The total weed density and weed biomass were also substantially reduced, but there were no effects on the growth or the yield of the P. vulgaris in the treated plots. The application of the leaf residue increased soil organic carbon and some macronutrients, including available nitrogen and potassium. High-performance liquid chromatographic (HPLC) analysis revealed the presence of phenolic and flavonoid compounds in the F. retusa leaves and the reduction of weeds may be attributed to the release of phytotoxins from the residue. Overall, the results suggested that F. retusa leaf residue can be used as part of the weed management strategy to control weeds in P. vulgaris crops.

摘要

鉴于需要最大限度地减少合成农用化学品对农业生态系统的环境影响并提高生产系统的可持续性，有必要确定杂草管理和作物保护的替代方法。经常修剪常绿乔木，包括榕树，可以提供大量的落叶，本研究旨在评估这种叶渣在园艺生产系统中的使用。评估了使用残留物作为有机土壤改良剂的效果，包括残留物控制青豆 ( Phaseolus vulgaris ) 作物中杂草的潜力。F. retusa叶渣的三种施用率（250、500和 1000 gm ^-2) 在两个位置施用于土壤。在这两个地点，处理以剂量和杂草物种依赖性方式显着降低了几种杂草物种的密度和生物量。总杂草密度和杂草生物量也显着降低，但对处理过的地块中的P. vulgaris的生长或产量没有影响。叶渣的施用增加了土壤有机碳和一些常量营养素，包括有效氮和钾。高效液相色谱 (HPLC) 分析表明，在F. retusa叶子中存在酚类和黄酮类化合物，杂草的减少可能归因于从残留物中释放植物毒素。总的来说，结果表明F. retusa叶渣可用作杂草管理策略的一部分，以控制P. vulgaris作物中的杂草。