Combined effects of magnesium and micronutrients on growth, yield, quality, and nutrient use efficiency of bitter gourd in terrace soils
摘要
Combined effects of magnesium (Mg), zinc (Zn), and boron (B) on bitter gourd (Momordica charantia L.) under terrace soils are not well documented. Therefore, a study was conducted to assess the combined effect of Mg, Zn, and B fertilization on bitter gourd growth, yield, nutrient use efficiency (NUE), postharvest quality, and profitability. Nine treatment combinations, based on varying levels of Mg, Zn, and B were tested in a RCBD with three replications. Treatments were T1 (Mg0Zn0B0 kg ha−1), T2 (Mg4Zn3B1.5 kg ha−1), T3 (Mg4Zn3B2 kg ha−1), T4 (Mg4Zn4B1.5 kg ha−1), T5 (Mg4Zn4B2 kg ha−1), T6 (Mg8Zn3B1.5 kg ha−1), T7 (Mg8Zn3B2 kg ha−1), T8 (Mg8Zn4B1.5 kg ha−1) and T9 (Mg8Zn4B2 kg ha−1). The combined application of Mg8Zn4B2 kg ha−1 (T9) significantly increased marketable fruit yield (14.8 t ha−1), which was 98% higher over control (T1). T9 demonstrated superior growth, yield attributes, and quality. This treatment produced maximum vitamin C (64.9 mg/100 g) and beta-carotene (151 mcg/100 g). T9 reduced postharvest weight loss during the 4-day storage period. Furthermore, T9 maximized the accumulation and uptake of N, P, K, S, Ca, Mg, Zn, and B; despite inconsistent apparent recovery efficiency for Mg, Zn, and B. T9 also generated the highest gross margin (2405 US$ha−1). Post-harvest soil analysis indicated slightly improved chemical properties relative to initial conditions. These results suggest that the combined application of Mg8Zn4B2 kg ha−1 is an optimal strategy for improving bitter gourd yield, quality, nutrient use efficiency (NUE), and profitability.