The Effect of Biofertilizer Type and Chicken Manure Dosage on the Growth and Yield of Kale (Brassica oleraceae L.)
Authors: Pujiastuti Elisabeth Sri , Simanjuntak Julfrin , Tarigan Juli Ritha , Sumihar Susana Tabah Trina 
Published: September 2024

Aims: To study the effect of the type of biofertilizer and the dose of chicken manure on the growth and yield of kailan (Brassica oleraceae L.).
Study Design: Experimental design, using factorial randomized block design consisting of two factors with three replications.
Place and Duration of Study: Experimental Station of the Faculty of Agriculture, Universitas HKBP Nommensen in Medan, from June to October 2023.
Methodology: The research used a factorial randomized block design consisting of two factors, namely the type of biofertilizer (P) and the dose of chicken manure (A), with three replications. The type of biofertilizer consisted of four levels, namely: P0 = No application of biofertilizer (control), P1 = IMO of pineapple peel (100 ml/l water), P2 = Eco-enzyme (1 ml/liter water), and P3 = Bio-Extreme biofertilizer (5 ml/m2). The dose of chicken manure (A) consisted of three levels, namely: A0 = 0 tons/ha (control), A1 = 15 tons/ha, and A2 = 30 tons/ha. Biofertilizer according to the treatment level was applied four times at 1 week before transplanting and 1, 2 and 3 weeks after transplanting, while the chicken manure was applied at 1 week before transplanting. The parameters observed were: plant height, number of leaves, root volume, root length, wet weight per plot, selling weight per plot, and yield per hectare.
Results: Both the type of biofertilizer and the dose of chicken manure treatments had no significant effect on all parameters, whereas the interaction between the type of biofertilizer and the dose of chicken manure had a significant effect on root length, but had no significant effect on other parameters. The relation between root length and the dose of chicken manure using IMO of pineapple peel was positive linear, with mathematical equation yP1 = 0.1733 x + 6.3833, with coefficient of determination R2 = 0.0788 and coefficient of correlation r = 0.2807, while the one using EE was positive quadratic, with mathematical equation yP2 = -0.3867 x2 + 0.5733 x + 7.25, with coefficient of determination R2 = 1 and coefficient of correlation r = 1.
Conclusion: The interaction between the type of biofertilizer and the dose of chicken manure had a significant effect on the root length of kale but had no significant effect on plant height and number of leaves at 4 WAT, root volume, wet weight per plot, selling weight per plot and yield per hectare. The best combination was obtained in P2A1 (eco enzyme as biofertilizer and chicken manure dose of 15 tons/ha) but it was not significantly different from the combinations of P1A0, P1A1, P2A2, P3A0, P3A1 and P3A2. With eco enzyme treatment, the relationship between the dose of chicken manure and root length was positive quadratic with the optimum dose of chicken manure for a maximum root length of 7.5 cm being 7.4 tons/ha. The dose of chicken manure had a significant effect on root length, but had no significant effect on other parameters, while the type of biofertilizer had no significant effect on all parameters.