Pengaruh Kombinasi Pupuk Organik Cair Limbah Kulit Kopi dan PGPR terhadap Pertumbuhan Vegetatif Bibit Kopi Robusta (Coffea canephora)

Abstract

NAUFAN ALI. Pengaruh Kombinasi Pupuk Organik Cair Limbah Kulit Kopi dan PGPR terhadap Pertumbuhan Vegetatif Bibit Kopi Robusta (Coffea canephora). Dibimbing oleh WANDA RUSSIANZI. Penelitian ini bertujuan mengkaji pengaruh kombinasi pupuk organik cair (POC) limbah kulit kopi dan plant growth promoting rhizobacteria (PGPR) serta berbagai konsentrasi terhadap pertumbuhan vegetatif bibit kopi robusta. Penelitian dilaksanakan di Sekolah Vokasi Institut Pertanian Bogor pada Desember 2025–April 2026 menggunakan rancangan kelompok lengkap teracak (RKLT) dua faktor dengan tiga ulangan. Faktor pertama terdiri atas POC, PGPR, dan kombinasi POC+PGPR, sedangkan faktor kedua terdiri atas konsentrasi 15, 30, 60, dan 90 ml/l, serta dua kontrol. Parameter yang diamati meliputi tinggi tanaman, diameter batang, jumlah daun, panjang akar, berat basah akar, berat kering akar, berat basah tajuk, dan berat kering tajuk. Hasil penelitian menunjukkan bahwa kombinasi POC+PGPR cenderung memberikan nilai tertinggi pada beberapa parameter, seperti tinggi tanaman (19,4 cm), diameter batang (2,80 mm), berat basah akar (2,19 g), berat basah tajuk (6,13 g), dan berat kering akar (0,4198 g). Interaksi perlakuan menunjukkan bahwa PGPR dengan konsentrasi 90 ml L1 memberikan hasil terbaik pada beberapa parameter pertumbuhan vegetatif bibit kopi robusta.

NAUFAN ALI. The Effect of the Combination of Coffee Pulp Waste Liquid Organic Fertilizer and Plant GrowthPromoting Rhizobacteria (PGPR) on the Vegetative Growth of Robusta Coffee (Coffea canephora) Seedlings. Supervised by WANDA RUSSIANZI. This study aimed to evaluate the effect of liquid organic fertilizer (LOF) derived from coffee pulp waste and Plant Growth Promoting Rhizobacteria (PGPR), as well as different application concentrations, on the vegetative growth of robusta coffee seedlings. The experiment was conducted at the Vocational School of IPB University from December 2025 to April 2026 using a Randomized Complete Block Design (RCBD) with two factors and three replications. The first factor consisted of LOF, PGPR, and LOF+PGPR, while the second factor consisted of concentrations of 15, 30, 60, and 90 mL L?¹, along with two control treatments. Observed variables included plant height, stem diameter, number of leaves, root length, fresh root weight, dry root weight, fresh shoot weight, and dry shoot weight. The results showed the LOF+PGPR combination tended to produce the highest values for plant height (19.4 cm), stem diameter (2.80 mm), fresh root weight (2.19 g), fresh shoot weight (6.13 g), and dry root weight (0.4198 g). The interaction treatment of PGPR at 90 mL L?¹ resulted in the best performance for several vegetative growth parameters of robusta coffee seedlings.