Effect of Bokashi and Water Deficiency on the Growth of Kailan (Brassica Oleracea Var. Acephala) in East Nusa Tenggara, Indonesia

Water scarcity poses a critical challenge to vegetable production in semi-arid regions such as East Nusa Tenggara, Indonesia, where sustainable soil amendment strategies are essential for maintaining crop productivity. This study investigated the interaction between water stress and coconut coir charcoal bokashi application on the growth and yield of kailan (Brassica oleracea var. alboglabra). The experiment was conducted at the State Agricultural Polytechnic of Kupang, East Nusa Tenggara, using a factorial Randomized Block Design (RBD) with three replications. Two factors were examined: water stress at three levels (no stress, 1-day stress, and 3-day stress) and bokashi dosage at four levels (0 g control, 75 g, 100 g, and 125 g per plant), yielding 12 treatment combinations. Data were analyzed using analysis of variance (ANOVA), and significant treatment differences were determined using Tukey's Honest Significant Difference (HSD) test at the 5% significance level. Both water stress and bokashi dosage significantly affected plant height at 15 and 45 days after planting (DAP). The combination of 3-day water stress with 125 g bokashi per plant produced the best overall growth performance, including the greatest plant height, leaf number, fresh weight, and dry weight per plant. These results suggest that appropriate bokashi amendment can partially compensate for the negative effects of water stress on kailan growth, offering a practical and sustainable strategy for vegetable production under water-limited conditions in East Nusa Tenggara.