香蕉园施用白花鬼针草的控草增效作用

目的] 探索香蕉园施用白花鬼针草的可行性。方法] 采用培养皿萌发试验生物测定法，以发芽率、发芽势、发芽指数、活力指数等化感效应指标评价白花鬼针草对蕉园4种优势杂草的化感作用，同时通过盆栽模拟试验探讨香蕉园施用白花鬼针草后杂草、香蕉和土壤三者的关系。结果] 当白花鬼针草浸提液浓度为0.0125 g·mL^-1时，对马唐综合化感效应为促进作用，对短叶水蜈蚣、牛筋草、柔弱斑种草综合化感效应为抑制作用，白花鬼针草浸提液浓度为0.025~0.1 g·mL^-1，对4种受体杂草综合化感效应均为抑制作用；白花鬼针草处理具有降低种子发芽率，延缓种子发芽时间的作用，同时对杂草萌发后的鲜重有微弱促进作用，但这种促进作用较弱，综合化感效应表现为抑制作用。随着白花鬼针草茎、叶施用量的增加，控草增效作用不断提升，当施用量为400 g·株^-1时，控草增效作用最佳，对杂草综合株防效为78.99%，综合鲜重防效为70.60%，香蕉苗生物量增加19.79%，土壤有机碳、碱解氮、速效钾依次增加8.72%、10.36%、16.30%。结论] 本研究初步探明了在香蕉园施用白花鬼针草具有防控蕉园优势杂草、提高土壤肥力和促进香蕉生长的效应。

Inhibition of weeds and promotion of banana growth by application of Bidens pilosa in banana plantation

Aim] We tested whether the plant Bidens pilosa has an allelopathic effect on dominant weeds in banana plantations. explored the feasibility of planting as an inter-row cover in banana plantations as a weed control measure.Method] In this study, the allelopathic effects of four concentration gradients of aqueous extracts from B. pilosa on the four dominant weeds in banana plantation were evaluated by the method of determination of biological index in seed germination test. At the same time, the relationship among weeds, banana and soil was studied by pot experiment.Result] The experiment of Petri dish germination of 4 kinds of weed seeds showed that when the concentration of aqueous extracts from B. pilosa is 0.0125 g·mL^-1, the comprehensive allelopathy effect on Digitaria sanguinalis germinatin was inhibited, but no such effect was observed for seeds of Kyllinga brevifolia, Eleusine indica and Bothriospermum tenellum. At the concentration of 0.025-0.1 g·mL^-1, the germination of all 4 weeds was inhibited; With the increase of application amount of B. pilosa, the effects of weed control and soil fertility increase gradually. When the application rate was 400 g·plant^-1, the control effect on weeds is the best, the control effect calculated by weed number was 78.99%, the control effect calculated by weed fresh weight was 70.60%. Additionally, we registered an increase in banana seedling biomass (19.8%), soil organic carbon (8.7%), soluble nitrogen (10.4%), and available potassium (16.3%).Conclusion] This study indicated that the application of B. pilosa in banana plantation can have multiple benefits:inhibit the dominant weeds between rows, improve soil fertility, and promote the growth of banana plants.