Pengaruh Berbagai Dosis Nitrogen dan Aplikasi EM4 terhadap Pertumbuhan Vegetatif dan Biomassa Stevia (Stevia rebaudiana Bertoni)

Abstract

Stevia (Stevia rebaudiana Bertoni) merupakan tanaman penghasil pemanis alami yang produktivitasnya ditentukan oleh pertumbuhan vegetatif dan biomassa daun. Penelitian ini bertujuan menganalisis pengaruh dosis nitrogen dan aplikasi EM4 terhadap pertumbuhan vegetatif, kandungan klorofil relatif, dan biomassa stevia aksesi Majalengka. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo, IPB University, pada Februari hingga Mei 2026 menggunakan Rancangan Kelompok Lengkap Teracak faktorial. Faktor pertama adalah dosis urea, yaitu 0%, 50%, dan 100% dosis acuan, sedangkan faktor kedua adalah tanpa dan dengan aplikasi EM4. Setiap kombinasi perlakuan diulang tiga kali sehingga terdapat 18 satuan percobaan. Hasil penelitian menunjukkan bahwa aplikasi EM4 dan dosis nitrogen tidak berpengaruh nyata terhadap tinggi tanaman dan nilai SPAD. Aplikasi EM4 meningkatkan jumlah cabang pada 8 MST, tetapi menurunkan luas daun serta bobot basah dan bobot kering batang. Dosis nitrogen berpengaruh terhadap jumlah daun, bobot basah batang, dan bobot basah daun, tetapi tidak berpengaruh terhadap bobot basah akar maupun seluruh komponen bobot kering. Perlakuan tanpa nitrogen menghasilkan jumlah daun, bobot basah batang, dan bobot basah daun tertinggi. Secara numerik, dosis nitrogen 100% menghasilkan bobot kering akar dan daun tertinggi, tetapi perbedaannya tidak nyata secara statistik. Interaksi antara aplikasi EM4 dan dosis nitrogen berpengaruh terhadap jumlah cabang pada 2 MST serta bobot basah akar, batang, dan daun. Tidak terdapat satu taraf perlakuan yang secara konsisten memberikan hasil terbaik pada seluruh peubah.

Stevia (Stevia rebaudiana Bertoni) is a natural sweetener-producing plant whose productivity is determined by vegetative growth and leaf biomass. This study aimed to analyse the effects of nitrogen dose and EM4 application on the vegetative growth, relative chlorophyll content, and biomass of the Majalengka accession of stevia. The study was conducted at the Leuwikopo Experimental Garden, IPB University, from February to May 2026 using a factorial randomised complete block design. The first factor was the urea dose, consisting of 0%, 50%, and 100% of the reference dose, while the second factor was EM4 application, consisting of treatments with and without EM4. Each treatment combination was replicated three times, resulting in 18 experimental units. The results showed that EM4 application and nitrogen dose had no significant effect on plant height and SPAD values. EM4 application increased the number of branches at 8 weeks after planting but reduced leaf area and the fresh and dry weights of stems. Nitrogen dose affected the number of leaves and the fresh weights of stems and leaves but had no significant effect on root fresh weight or any dry biomass component. The treatment without nitrogen produced the highest number of leaves and fresh weights of stems and leaves. Numerically, the 100% nitrogen dose produced the highest root and leaf dry weights, although the differences were not statistically significant. The interaction between EM4 application and nitrogen dose affected the number of branches at 2 weeks after planting and the fresh weights of roots, stems, and leaves. No single treatment level consistently produced the best result across all variables.