Effectiveness of coffee fruit skin bokashi and soybean sprout extract in enhancing the growth of arabica coffee seedlings (Coffea arabica L.)

This study aims to evaluate the effectiveness of giving coffee fruit skin bokashi and bean sprout extract on the growth of Arabica coffee seedlings (Coffea arabica). This study was conducted from June to September 2024 at PT Sulotco Jaya Abadi. The experimental design used was factorial in a Randomized Block Design (RAK) with two factors, namely coffee fruit skin bokashi (K) and bean sprout extract (T). The K factor consists of three treatment levels (K0 = 0 grams/polybag, K1 = 400 grams/polybag, K2 = 800 grams/polybag), while the T factor consists of three treatment levels (T0 = 0 ml/polybag, T1 = 300 ml/polybag, T2 = 600 ml/polybag). Each treatment combination was repeated three times so that there were 27 experimental units. Data were analyzed using analysis of variance (ANOVA) to determine the effect of treatment and interaction between factors. This was then continued with an honest significant difference test (HSD) at the 5% level if there was a significant difference. The results showed that the combination of coffee fruit skin bokashi and bean sprout extract had a significant effect on the growth of Arabica coffee seedlings. The T2K2 treatment (600 ml bean sprout extract/polybag + 800 grams of coffee fruit skin bokashi/polybag) produced the best growth with a significant increase in plant height (12.33 cm), number of leaves (10.11 strands), leaf width (7.00 cm), root length (12.34 cm), and dry weight of the plant (3.34 g). This increase indicates that coffee fruit skin bokashi increases the availability of nutrients in the soil, while bean sprout extract acts as a natural bioactivator that stimulates plant growth through auxin and cytokinin content. Thus, the combination of coffee fruit skin bokashi and bean sprout extract can be an alternative organic fertilizer and natural growth regulator that is environmentally friendly and sustainable in Arabica coffee cultivation.