IDENTIFIKASI KARAKTER MORFO-FISIOLOGI PENENTU PRODUKTIVITAS JAMBU METE (Anacardium occidentale)

Abstract

ABSTRAK Produktivitas jambu mete di Indonesia masih rendah karena budidayanya yang masih sederhana dan belum menggunakan bahan tanaman unggul. Hasil tanaman ditentukan oleh beberapa karakter morfo- fisiologi seperti luas dan tebal daun, jumlah stomata, laju fotosintesis, kandungan klorofil, relative water content (RWC), dan potential osmotik daun. Penelitian ini bertujuan untuk mengetahui karakter morfo-fisiologi yang menentukan hasil jambu mete. Penelitian dilaksanakan di Kebun Percobaan Cikampek dan Laboratorium, Balittro, Bogor, Jawa Barat, pada bulan Januari-Desember 2012. Bahan tanaman yang digunakan adalah dua varietas jambu mete produksi tinggi (B02 dan GG1) dan tiga varietas produksi rendah (Laode Gani, Laode Kase, dan Laura). Tanaman dibedakan dalam tiga kelompok umur (5, 8, dan 17 tahun). Parameter yang diamati karakter morfologi seperti ketebalan daun (μm), luas daun (cm 2 ), produksi gelondong (kg/tanaman), berat kering daun (g/daun), anatomi (jumlah stomata), dan parameter fisiologi meliputi kandungan klorofil (a+b) (%), laju fotosintesis (μmol CO 2  m -2 s -1 ), karbohidrat daun (%), potensial air daun (bar), dan Relative Water Content (RWC) (%). Untuk mengetahui parameter morfo-fisiologi yang berpengaruh nyata terhadap produksi dilakukan uji komponen penentu hasil, yaitu peubah morfo- fisiologi terhadap produksi gelondong mete. Hasil penelitian menunjukkan peubah klorofil tanaman jambu mete berpengaruh nyata antar aksesi. Hasil analisis antar peubah morfo-fisiologi dan komponen hasil menunjukkan hanya peubah klorofil yang berkorelasi positif terhadap hasil gelondong aksesi jambu mete yang berproduktivitas tinggi. Fungsi hasil digambarkan dalam formula ln hasil gelondong = 2,01 + 11,0 ln klorofil , sedangkan pada aksesi yang produktivitasnya rendah peubah klorofil tidak berpengaruh nyata. Fungsi ini mengindikasikan apabila kandungan klorofil meningkat 1% maka produksi gelondong akan meningkat 11%. Kata kunci: Anacardium occidentale, karakter morfo-fisiologi, produksi ABSTRACT Cashew productivity in Indonesia is still low, due to improper cultivation technique and the use of unimproved varieties. Crop yield is determined by several morpho-physiological characters such as leaf area, leaf thickness, the number of stomata, the rate of photosynthesis, chlorophyll content, relative water content (RWC), and leaf osmotic potential. This study aimed to obtain morpho-physiological characters affecting cashew production. The research was conducted in the Cikampek Experimental Station and in the Laboratory, ISMECRI, Bogor, West Java, from January to December 2012. The plant material used were two selected high-yielding varieties (B02 and GG1) and three low-yielding varieties (Laode Gani, Laode Kase, and Laura). The plants were divided into three age groups (5, 8, and 17 years). Parameters measured were morphological characteristics such as leaf thickness (µm), leaf area (cm 2 ), leaf dry weight (g/leaf), and nut yield (kg/tree), as well as anatomical characteristic such as the number of stomata, and physiological parameters consisted of chlorophyll content (a+b) (%), photosynthetic rate (µmol CO2 m -2 s -1 ), leaf carbohydrate content (%), leaf water potential (bar) and relative water content (RWC) (%). Data were analysed using component test to find morpho-physiological characteristics which was affecting nut yield. The result showed chlorophyll content was significantly affected nut yield among varieties as shown in the following function: ln nut yield = 2.01 + 11.0 ln chlorophyll . The result indicated that when the chlorophyll content increased 1% the nut yield would increase 11%. Keywords: Anacardium occidentale, morpho-physiological characteris- tic, production