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

Abstract

BackgroundThere are a variety of ways of increasing crop diversity to increase agricultural sustainability and in turn having a positive influence on nearby natural ecosystems. 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.ResultsIn 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 demonstrated a higher competitive ability than mile-a-minute. Except pH, other soil nutrient contents of initial soil (CK) were significantly higher than those of seven treatments. The concentrations of soil organic matter, total N, total K, available N, available P, available K, exchange Ca, exchange Mg, available Mn, and available B were significantly greater (P < 0.05) in mile-a-minute monoculture soil than in sweet potato monoculture soil, and were reduced by the competition of sweet potato in the mixture.ConclusionsEvidently sweet potato has a competitive advantage in terms of plant growth characteristics and greater absorption of soil nutrients. Thus, planting sweet potato is a promising technique for reducing infestations of mile-a-minute, providing weed management benefits and economic returns from harvest of sweet potatoes. This study also shows the potential value of replacement control methods which may apply to other crop-weed systems or invaded natural ecosystems.

Morpho-Physiological Evaluation of Sweet Potato (Ipomoea batatas L.) Genotypes in Acidic Soil

“…Variability of the non-storage root weight depends on the growth and development of the sweet potato genotypes. The findings of the present study agrees with the agreement of Naskar and Chowdhury (1994) and Shen et al (2015) who stated that the adventitious root weight ranges from 1-2 g. Similarly, dry weight of on-storage root differs significantly among the sweet potato genotypes. The maximum dry matter of fibrous roots was recorded in the genotypes JSP-1 (3.73 g) which is statistically similar to JSP-6 (3.62 g) and the minimum dry weight found in JSP-2 (1.63 g) (Fig.…”

“…The findings of the present experiment are in agreement with the findings of Choudhury et al (1986). Shen et al (2015) reported that number of vine plantG 1 ranges from 10.4-13.3 due to available nutrient present in soil. In the present study, vine number was not satisfactory because of the tip portion of vine dry in all the genotypes upto the maturity for the reason of acidic soil as a result new vine could not grow.…”

Flooding with shallow water promotes the invasiveness of Mikania micrantha

“…Although M. micrantha is found in various habitats, such as disturbed roadsides, wastelands, plantations and secondary forests in low-altitude valleys, barren farmlands, and orchards, as well as the sides of ditches and rivers (Zhang et al, 2004), some studies have shown that the species prefers humid environments (Murphy et al, 2013;Shen et al, 2015). However, the effect of soil moisture on its F I G U R E 1 The locations of 162 Mikania micrantha populations in drylands (dry habitats; n = 74), on riverbanks (wet habitats; n = 36), and in wetlands with shallow water (aquatic habitats; n = 52) in the Pearl River Delta region of Guangdong, China population size has rarely been addressed (Xu, Shen, Zhang, Li, & Zhang, 2013).…”

Specialist nectar-yeasts decline with urbanization in Berlin

“…Nectar-dwelling yeasts are known to influence the sugar concentration and composition of nectar4, and may also affect the mutualistic interaction among plants and pollinators5. Given that nectar-dwelling yeasts rely on pollinator visitation for movement from one flower to another6, diversity and dispersal of nectar-borne yeasts is closely related to pollinator activity and diversity789.…”

“…It is known, however, that nectar sugar content, yeast thermal tolerance, and individual growth rates11 influence nectar yeast community composition. Moreover, multiple pollinator visits removing nectar content of the same flower impede the proliferation of slow growing yeasts, and may thereby select against the relatively slow growing generalists89. Next to these factors, the adaptation of yeast species to certain pollinators (e.g.…”