Influence of Weeds on Yacon Initial Growth and Development

ABSTRACT: The consumption of yacon has been increasing around the world due to the nutritional and pharmaceutical properties of this plant. The growing commercial interest in yacon (Smallanthus sonchifolius) generates a demand for crop management research studies, including the effect of weed competition on yacon, which was not yet studied. Thus, this study was performed with the objective of evaluating the effects of weed competition on yacon development and growth. The experimental design was completely randomized with four treatments and seven replicates. Treatments were yacon with the interference of four weed species: Cyperus rotundus L. (nutgrass), Commelina benghalensis L. (tropical spiderwort), Amaranthus viridis L. (slender amaranth) and Bidens pilosa L. (hairy beggarticks). The experiment was conducted in a greenhouse, using 10 dm3 pots. Plant height, number of leaves, number of stems, leaf area, fresh and dry mass weight (total and partial), and chlorophyll A, B and total were evaluated. The weed competition resulted in a decrease in the yacon development (height, number of leaves, number of stems, leaf area), photosynthetic rate (decreased chlorophyll content A, B and total) and yield, as also decreased the accumulation of fresh and dry biomass of tuberous roots. C. benghalensis L. and A. viridis L. were the weeds most affecting the development and growth of yacon.

摘要：鉴于菊薯（yacon）兼具营养与药用价值，其全球消费量逐年攀升。当前市场对菊薯（Smallanthus sonchifolius）的商业需求持续增长，推动了作物栽培管理相关研究的开展，其中杂草竞争对菊薯生长影响的研究此前尚未见报道。为此本研究旨在评估杂草竞争对菊薯生长发育的影响。
本实验采用完全随机设计，设置4组处理与7次生物学重复。处理组为菊薯分别与4种杂草共生的组合：香附子（Cyperus rotundus L.，俗称碎米莎草）、孟加拉鸭跖草（Commelina benghalensis L.，俗称热带鸭跖草）、皱果苋（Amaranthus viridis L.，俗称细苋）以及三叶鬼针草（Bidens pilosa L.，俗称毛鬼针草）。实验于温室中开展，使用容积为10 dm³的栽培盆。
本研究测定的指标涵盖株高、叶片数、茎秆数、叶面积、鲜重与干重（总重及分部位重）以及叶绿素A、叶绿素B与总叶绿素含量。
结果表明，杂草竞争会抑制菊薯的生长发育（株高、叶片数、茎秆数及叶面积均显著下降），降低其光合速率（表现为叶绿素A、B及总叶绿素含量下降）与块根产量，同时减少块根鲜、干生物量的积累。其中，孟加拉鸭跖草与皱果苋对菊薯生长发育的抑制作用最为显著。