Eny Widajati

PENGARUH UMUR PANEN RIMPANG TERHADAP PERUBAHAN FISIOLOGI DAN VIABILITAS BENIH JAHE PUTIH BESAR SELAMA PENYIMPANAN

ABSTRAK Salah satu faktor yang menentukan daya simpan benih jahe putih besar (JPB) adalah mutu. Mutu benih sangat ditentukan oleh tingkat kemasakan rimpang. Penelitian bertujuan untuk mengetahui pengaruh umur panen terhadap perubahan fisiologi dan viabilitas benih selama penyimpanan. Penelitian dilaksanakan di Rumah Kaca dan Laboratorium Teknologi Benih, Balai Penelitian Tanaman Rempah dan Obat serta Laboratorium Pascapanen IPB Bogor, mulai bulan Juli 2012 sampai dengan Februari 2013. Rancangan yang digunakan adalah acak lengkap (RAL) dengan lima ulangan. Perlakuan yang diuji adalah tiga tingkat umur panen benih 7, 8, dan 9 bulan setelah tanam (BST). Pengamatan dilakukan terhadap perubahan fisiologis (penyusutan bobot, persentase rimpang bertunas, tunas, kadar air, dan laju respirasi), serta viabilitas rimpang benih (daya tumbuh, tinggi, dan bobot kering bibit). Hasil penelitian menunjukkan rimpang benih umur 7 dan 8 BST mempunyai daya simpan terbaik karena menghasilkan masing-masing total angka penyusutan bobot lebih rendah (24,65 dan 25,25%) dan tunas lebih pendek (0,30 dan 1,08 cm) dibandingkan dengan umur panen 9 BST (27,13% dan 1,62 cm), selama 4 bulan disimpan. Masa dormansi rimpang benih JPB mulai pecah setelah mengalami periode simpan 2 bulan. Pertumbuhannya mulai seragam setelah 3 bulan simpan. Umur panen jahe 7 dan 8 BST mempunyai derajat dormansi yang lebih tinggi dibanding 9 BST. Rimpang benih umur panen 7, 8, dan 9 BST mempunyai daya tumbuh tinggi (>95%) dan pertumbuhan bibit seragam setelah 3 bulan disimpan. Kata kunci: Zingiber officinale Rosc., penyimpanan, benih, perubahan fisiologis, viabilitas ABSTRACT One of the factors that determine the storability of seed rhizome of white big ginger (WBG) is quality. The quality is determined by the maturity levels of seed rhizome. The aim of the experiment was to observe the effect of harvesting time on physiological changes and seed viability of WBG seed rhizomes during the storage. The experiment was conducted at Green House and Seed Technology Laboratory of Indonesian Spice and Medicinal Crops Research Institute, Bogor and Postharvest Laboratory, IPB, from July 2012 to February 2013. The experiment was arranged in a completely randomized design with five replications. The treatments tested were three levels of WBG seed rhizome harvesting time: 7, 8, and 9 month after planting (MAP). Variables observed were physiological changes of seed rhizomes during the storage (weight loss, sprouting percentage, shoot height, respiration rate, and moisture content) and viability (growth ability, height, and dry weight of the seedling). The results showed that seed rhizomes at 7 and 8 had the best storability, since it was produced each low rate of weight loss (24.65 and 25.25%), and shoots shorter (0.3 and 1.08 cm) than 9 MAP (27.13% and 1.62 cm), for 4 months in storage. Dormancy of WBG seed rhizomes has been broken after 2 months in storage. Harvesting at 7 and 8 showed a degree of dormancy higher than the harvesting age 9 MAP. Harvesting time at 7, 8, and 9 MAP had high growth ability (> 95%) and uniform seedling growth after 3 months in storage. Keywords: Zingiber officinale Rosc., storage, seed, physiological changes, viability

Pola Topografi Pewarnaan Tetrazolium sebagai Tolok Ukur Viabilitas dan Vigor Benih Kedelai (Glycine max L.Merr.) untuk Pendugaan Pertumbuhan Tanaman di Lapangan

Topographical tetrazolium (TZ) pattern to determine viability, vigor and field stand on soybean seeds cv. Burangrang was studied. Laboratory test for standard germination, vigor index, speed of germination, accelerated aging, seedling growth rate and field performances were performed on five lots (A,B,C,D,E) of soybean seeds. The viability and vigor categories of each pattern were determined by Root Mean Square (RMS), regression, and correlation analysis. Ten topographical patterns were recognized. The laboratory test results and field performances were compared with topographical pattern. Combination of patterns 1,2,3,4 (embryonic axis and cotyledon completely and/or gradually stained) selected as viable category as it gave the least RMS value, the highest determination (R 2 ) and correlation (r) coefficient with standard germination (RMS=6,46; R 2 =0,37; r=0,61). Combination of patterns 1,2,3 (embryonic axis and cotyledon completely stained) selected as vigor category as it gave the least RMS value, the highest R 2 and r with relative speed of germination (RMS=7,96; R 2 =0,44; r=0,66), vigor index (RMS=6,66; R 2 =0,36; r=0,6), field emergence (R 2 =0,79; r=0,89) and field stand (R 2 =0,65; r=0,80). The combination of patterns 1,2,3 is