Effect of Rhizobium leguminosarum Inoculation and Mulching on Growth and Yield of Chinese Long Bean (Vigna unguiculata subsp. sesquipedalis)

Abstract

An experiment was conducted to evaluate the influence of Rhizobium leguminosarum inoculation and mulching on the growth and yield of Chinese long bean (Vigna unguiculata subsp. sesquipedalis) in Palungtar, Nepal. A split-plot design was used for the experiment, which was replicated four times. Plastic, straw, and no-mulch conditions constituted the main plot factor, while seeds with or without Rhizobium inoculation constituted the sub-plot elements. Growth parameters and yield-related traits of Chinese long beans were recorded at 15-day intervals. Transparent plastic mulching resulted in earlier flowering (46 days), while seed inoculation with Rhizobium resulted in a higher mean number of nodules (106.92) than non-inoculated treatments, with transparent plastic mulching resulting in the highest mean number of nodules (108.21). At 60 days after showing (DAS), plant height was greater in the inoculated treatment (69.23 cm), while at 30 DAS, the non-inoculated treatment had a higher number of leaves (22.28 cm). Similarly, pod length (49.98 cm), pod yield per plant (348.01 g), and total yield per hectare (16.07 t/ha) were all significantly higher with both plastic mulch and seed inoculation with Rhizobium than with the other treatments alone. A positive correlation was observed between plant height (0.81), number of branches (0.44), number of leaves (0.81), number of nodules per plant (0.6), and pod yield. This supports the potential benefits of using seed inoculation with Rhizobium in combination with mulching to improve Chinese long bean growth and increase yield as demonstrated by the results of this study.