ABSTRACT

Globally, the guava root-knot nematode (Meloidogyne enterolobii) is becoming an emerging threat of note in crops with or without Mi resistance genes. Watermelon (Citrullus lanatus) cultivars are highly susceptible to Meloidogyne species, with all cultivars without genotypes with resistance to the genus. In contrast, nematode management options for watermelon production had since the withdrawal of fumigant nematicides been constrained. The objective of this study was to investigate the comparative efficacy of the locally-developed cucurbitacin phytonematicides and commercially available synthetic chemical nematicide Velum on growth and fruit yield and quality of watermelon cv. ‘Congo’, along with its accumulation of foliar nutrient elements and suppression of M. enterolobii population densities under field conditions. Nemarioc-AL and Nemafric-BL phytonematicides were each applied biweekly at 2% per seedling using 500 ml solution, while Velum was applied once using 500 ml solution at 0.08 ml/15 L chlorine-free water. At 90 days after the treatments, relative to untreated control, the two phytonematicides and Velum (a.i. fluopyram) significantly increased plant growth, fruit yield and quality, although with the accumulation of phosphorus in leaf tissues, with efficacies of the three products being comparable. Similarly, relative to untreated control, the three products significantly reduced nematode eggs and juveniles in roots and juveniles in soil, with efficacies that were significantly comparable. In conclusion, the benefits of phytonematicides on the productivity of watermelon cv. ‘Congo’ and suppression of population densities of M. enterolobii were comparable.

摘要

在全球范围内，番石榴根结线虫 ( Meloidogyne enterolobii ) 正在成为具有或不具有 Mi 抗性基因的作物中的新威胁。西瓜（Citrullus lanatus）品种对根结线虫物种高度敏感，所有品种都没有对该属的抗性基因型。相比之下，西瓜生产的线虫管理选择自熏蒸杀线虫剂的退出受到限制。本研究的目的是研究本地开发的葫芦素类植物杀虫剂和市售的合成化学杀线虫剂 Velum 对西瓜品种生长和果实产量和品质的比较效果。'刚果'，以及其叶面营养元素的积累和抑制M. enterolobii野外条件下的人口密度。Nemarioc-AL 和 Nemafric-BL 植物杀灭剂每双周使用 500 ml 溶液以每株幼苗 2% 施用一次，而 Velum 使用 0.08 ml/15 L 无氯水的 500 ml 溶液施用一次。在处理后 90 天，相对于未处理的对照，两种植物杀灭剂和 Velum (ai fluopyram) 显着提高了植物生长、果实产量和品质，尽管磷在叶组织中积累，三种产品的功效相当。同样，相对于未处理的对照，这三种产品显着减少了根中的线虫卵和幼虫以及土壤中的幼虫，其功效具有显着可比性。总之，植物杀虫剂对西瓜产量的好处。M. enterolobii具有可比性。