KOMPATIBILITAS DAN PERTUMBUHAN BENIH ALPUKAT (Persea americana Mill.) HASIL GRAFTING PADA MEDIA TANAH DARI KHDTK HUTAN DIKLAT RUMPIN

Abstract

Hutan lindung merupakan kawasan hutan yang berfungsi melindungi sistem penyangga kehidupan, seperti mengatur tata air, mencegah banjir dan erosi, mengendalikan intrusi air laut, serta memelihara kesuburan tanah. Pemanfaatan kawasan ini dapat dilakukan secara terbatas tanpa mengurangi fungsinya melalui pemanfaatan kawasan, jasa lingkungan, hasil hutan bukan kayu (HHBK), dan kegiatan perhutanan. Pengembangan usaha pada hutan lindung dianjurkan menggunakan tanaman berkayu atau multi-purpose tree species (MPTS) yang menghasilkan HHBK tanpa penebangan. Tanaman alpukat (Persea americana Mill.) termasuk jenis MPTS yang dapat dimanfaatkan buah, daun, bunga, dan biji. Produksi alpukat di Indonesia belum sepenuhnya memenuhi kebutuhan pasar karena keterbatasan ketersediaan bibit berkualitas dan penggunaan bibit dari biji yang menghasilkan tanaman berbuah lama serta memiliki sifat yang tidak seragam. Perbanyakan vegetatif menggunakan teknik sambung pucuk (grafting) dapat menghasilkan bibit yang cepat berbuah dan memiliki sifat yang sama dengan induknya. Keberhasilan grafting dipengaruhi oleh kesesuaian varietas batang atas, kualitas bahan tanam (batang atas dan batang bawah), teknik penyambungan, dan media tanam yang menyediakan air serta unsur hara. Oleh karena itu, penelitian ini bertujuan menganalisis pengaruh perbedaan varietas batang atas Miki dan Aligator dan media tanam tanah hutan dan media standar terhadap keberhasilan dan pertumbuhan benih alpukat hasil grafting. Penelitian dilaksanakan pada Juli 2025 hingga Januari 2026. Prosedur kerja pada penelitian dilakukan di Rumpin Seed Source Nursery Center. Pengamatan keberhasilan dan pertumbuhan benih hasil grafting dilakukan di Rumpin Seed Source Nursery Center dan Laboratorium Departemen Silvikultur, IPB University. Analisis anatomi tanaman dilakukan di Pusat Penelitian dan Pengembangan Hutan Bogor. Analisis serapan hara daun dan kimia media tanam dilakukan di Laboratorium Pengujian Departemen Agronomi dan Hortikultura, IPB University. Penelitian menggunakan Rancangan Acak Lengkap Faktorial dengan 2 faktor, yaitu varietas batang atas alpukat (Miki dan Aligator) dan media tanam (media tanah hutan dan media standar). Tanah hutan berasal dari Kawasan Hutan dengan Tujuan Khusus Hutan Diklat Rumpin sebagai pendekatan terhadap kondisi media tanah hutan. Kombinasi kedua faktor menghasilkan 4 perlakuan, yaitu varietas batang atas Miki pada media tanah hutan (A1B1), varietas batang atas Miki pada media standar (A1B2), varietas batang atas Aligator pada media tanah hutan (A2B1), dan varietas batang atas Aligator pada media standar (A2B2). Setiap perlakuan terdiri atas 3 ulangan dan 15 benih pada setiap ulangan sehingga total benih berjumlah 180 benih alpukat hasil grafting. Penelitian juga menggunakan benih alpukat kontrol tanpa grafting, yaitu varietas Mentega Lokal Bogor pada media tanah hutan (A3B1) dan varietas Mentega Lokal Bogor pada media standar (A3B2). Metode penyambungan yang digunakan adalah model sambung baji. Pengamatan peubah meliputi keberhasilan grafting, jumlah tunas, panjang tunas, jumlah daun, tinggi benih, laju pertumbuhan benih, berat basah akar, berat kering akar, dan volume akar. Pengamatan anatomi dilakukan pada bidang sambungan benih hasil grafting. Analisis kimia media tanam meliputi pH H2O, C-Organik, N-Total, P-Tersedia, P-Potensial, K-Tersedia, K-Potensial, K-dd, dan KTK. Analisis serapan hara daun pada penelitian ini adalah serapan hara nitrogen (N), fosfor (P), dan kalium (K) daun. Keberhasilan grafting benih alpukat mencapai >80%. Batang atas varietas Miki dan Aligator dengan batang bawah varietas Mentega Lokal Bogor memiliki keberhasilan grafting yang sama. Penanaman pada media tanah hutan dan media standar memiliki memiliki keberhasilan grafting yang relatif sama. Varietas batang atas Aligator pada media standar memiliki jumlah tunas yang lebih tinggi dan laju pertumbuhan awal yang lebih baik. Varietas Mentega Lokal Bogor sebagai benih kontrol pada media tanah hutan maupun media standar secara umum memiliki pertumbuhan akar yang lebih tinggi dibandingkan dengan benih hasil grafting varietas Miki dan Aligator. Benih hasil grafting pada media tanah hutan maupun media standar secara umum memiliki serapan hara daun yang lebih tinggi dibandingkan dengan benih kontrol. Pertumbuhan benih hasil grafting dipengaruhi oleh varietas batang atas dan media tanam yang digunakan.

Protected forests are forest areas that serve to protect life-support systems, such as regulating water management, preventing floods and erosion, controlling seawater intrusion, and maintaining soil fertility. These areas can be utilized to a limited extent without compromising their functions through land use, environmental services, non-timber forest products (NTFPs), and forestry activities. Business development in protected forests is encouraged to use woody plants or multi-purpose tree species (MPTS) that produce NTFPs without logging. The avocado tree (Persea americana Mill.) is a type of MPTS whose fruit, leaves, flowers, and seeds can be utilized. Avocado production in Indonesia has not yet fully met market demand due to the limited availability of high-quality seedlings and the use of seedlings from seeds, which produce plants that take a long time to bear fruit and exhibit inconsistent characteristics. Vegetative propagation using grafting techniques can produce seedlings that bear fruit quickly and possess the same characteristics as their parent plants. The success of grafting is influenced by the compatibility of the scion variety, the quality of the planting material (scion and rootstock), the grafting technique, and the growing media that provides water and nutrients. Therefore, this study aims to analyze the effects of differences in the Miki and Aligator scion varieties and forest soil media and standard growing media on the success and growth of grafted avocado seedlings. The research was conducted from July 2025 to January 2026. Fieldwork was carried out at the Rumpin Seed Source Nursery Center. Observations of the success and growth of grafted seedlings were conducted at the Rumpin Seed Source Nursery Center and the Department of Silviculture Laboratory at IPB University. Plant anatomy analysis was conducted at the Bogor Forest Research and Development Center. Analysis of leaf nutrient uptake and growing media chemistry were conducted at the Testing Laboratory of the Department of Agronomy and Horticulture, IPB University. The study used a Complete Randomized Factorial Design with two factors: avocado scion varieties (Miki and Aligator) and growing media (forest soil media and standard media). The forest soil media was sourced from the Rumpin Special Purpose Forest Area for Forestry Education and Training (Kawasan Hutan dengan Tujuan Khusus Hutan Diklat Rumpin) as an approximation to the condition of the forest soil media. The combination of these two factors resulted in 4 treatments: the Miki scion variety in forest soil media (A1B1), the Miki scion variety in standard media (A1B2), the Aligator scion variety in forest soil media (A2B1), and the Aligator scion variety in standard media (A2B2). Each treatment consisted of 3 replicates and 15 seeds in each replication, resulting in a total of 180 grafted avocado seedlings. The study also used control avocado seedlings without grafting, the Mentega Lokal Bogor variety in forest soil media (A3B1) and the Mentega Lokal Bogor variety in standard media (A3B2). The grafting method used was the wedge grafting model. Variables observed included grafting success, number of shoots, shoot length, number of leaves, seedling height, seedling growth rate, fresh root weight, dry root weight, and root volume. Anatomical observations were conducted on the graft union of the grafted seedlings. Chemical analysis of the growing media included pH of water, organic carbon (C), total nitrogen (N), available phosphorus (P), potential phosphorus (P), available potassium (K), potential potassium (K), exchangeable potassium (K), and cation exchange capacity (CEC). The analysis of leaf nutrient uptake in this study focuses on the uptake of nitrogen (N), phosphorus (P), and potassium (K) by the leaves. The success rate of avocado seedling grafting reached >80%. Scions of the Miki and Aligator varieties grafted onto rootstocks of the Mentega Lokal Bogor variety showed the same grafting success rate. Planting in forest soil media and standard media resulted in relatively similar grafting success rates. The Aligator scion variety planted in standard media produced a higher number of shoots and exhibited a better initial growth rate. The Mentega Lokal Bogor variety, used as the control seedling in both forest soil media and standard media, generally exhibited higher root growth compared to grafted seedlings of the Miki and Aligator varieties. Grafted seedlings in both forest soil media and standard media generally exhibit higher nutrient uptake by the leaves compared to the control seedlings. The growth of grafted seedlings is influenced by the scion variety and the growing media used.