Suppression of the invasive plant mile-a-minute (Mikania micrantha) by local crop sweet potato (Ipomoea batatas) by means of higher growth rate and competition for soil nutrients

Background: Competitive crops may provide potent management tools against invasive plants. To elucidate the competitive mechanisms between a sweet potato crop (Ipomoea batatas) and an invasive plant mile-a-minute (Mikania micrantha) field experiments were carried out in Longchuan County of Yunnan Province Southwest China utilizing a de Wit replacement series. The trial incorporated seven ratios of sweet potato and mile-a-minute plants in 25 m2 plots. Results: In monoculture the total biomass biomass of adventitious root leafstalk length and leaf area of sweet potato were all higher than those of mile-a-minute and in mixed culture the plant height branch leaf stem node adventitious root flowering and biomass of mile-a-minute were suppressed significantly (P<0.05). The relative yield (RY) of mile-a-minute and sweet potato was less than 1.0 in mixed culture indicating that intraspecific competition was less than interspecific competition. The competitive balance index of sweet potato de...