. 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.

Seed vigour is one of the seed parameters that determines seed quality for successful crop production. An experiment was conducted at Bogor Agricultural University to develop a seed vigour testing method for the true seed of shallot (TSS) using a single count of radicle emergence (RE) that can be used to estimate germination percentage of normal seedlings in the laboratory and field emergence. Nine artificially made seed lots of TSS were used in this experiment which were germinated at two different temperatures i.e., at 20±1℃ and at 25±1℃ (room temperature). The experiments were arranged in a completely randomized design (CRD) with a repeated measurement, having four replicates. The results showed that a single count of RE at 72 and 68 hours germinated at 20±1℃ and 25±1℃ respectively, were able to predict germination percentage in the laboratory 12 days after sowing and field emergence 14 days after planting. Regression and correlation analysis values of RE were predictive to germination percentage with r=0.891 and R 2 =0.951 (p<0.01) for seed lots germinated at 20±1℃ and r=0.924 and R 2 =0.875 (p=<0.01) for seed lots germinated at 25±1℃. Furthermore, RE was predictive to field emergence (FE %) with r=0.953 and R 2 =0.909 (p<0.01) and r=0.865 and R 2 =0.732 (p<0.01) for seed lots germinated at 20±1℃ and 25±1℃ respectively. A single count of RE correlated well with other vigour tests at 68 hours and 72 hours for seed lots germinated at 25±1℃ and/or 20±1℃ respectively, then it can be used as one of the methods for seed vigour test for TSS.

The catch production of this species has declined since 2015. This study aims to assess growth, mortality, and exploitation rate parameters of P. leopardus taken from Napan Yaur water, Cenderawasih Bay National Park (CBNP), Indonesia. The data were collected during periods of February to March 2016. Growth and mortality parameters were analyzed using von Bertalanffy method. Some fish samples used in this study was 123 individuals, with the average length of 32.34 ± 5.13 cm, the maximum length of 48.00 cm and minimum length of 24.5 cm. The von Bertalanffy analysis showed that the growth coefficient (K) was 0.34 year-1 , L∞ was 47.78 cm and t 0 was-0.09 year-1. The estimation of total mortality (Z) was 1.61 year-1 , natural mortality (M) was 0,75year-1 for fishing mortality (F) was 0.86 year-1 , and exploitation rate (E) was 0.53 year-1. The results indicated that most P. leopardus caught were at the pre-maturity size (age) and have been exploited at slightly above its optimum exploitation level. Nevertheless, P. leopardus is categorized as fast growing and long-lived fish species. These findings are important to fisheries management and conservation authorities to fish exploitation in the future.

<p><em> </em><em>Tujuan penelitian ini adalah </em><em>untuk </em><em>mempelajari pengaruh priming </em><em>dalam</em><em> mempertahankan vigor benih kacang panjang selama dalam penyimpanan. </em><em>Perlakuan priming yang dilakukan adalah perendaman benih dalam air, KNO₃, CaCl₂, asam askorbat, dan pelembapan diantara kertas selama dua jam. </em><em>Perlakuan </em><em>priming</em><em> menyebabkan peningkatan kadar air benih hingga sekitar 9%, sedangkan perlakuan pelembapan </em><em>diantara kertas </em><em>hanya meningkatkan kadar air 1-2 %</em><em> dibanding kontrol</em><em>. Setelah selesai perlakuan, benih </em><em>dikeringkan kembali hingga kadar air 12-13% lalu disimpan </em><em>di ruang kamar</em><em>(26-30.8 °C; RH 68-77 %) </em><em>dan AC</em><em> (±20 °C; RH ±50%) </em><em>menggunakan plastic polipropilen</em><em> (tebal 0.08 mm)</em><em>. Perlakuan priming mampu mempertahankan indeks vigor dan kecepatan tumbuh sampai dengan </em><em>15 minggu penyimpanan </em><em>baik pada penyimpanan ruang AC ataupun kamar.</em><em> Perlakuan perendaman dalam air  dapat menjadi pilihan terbaik sebagai perlakuan benih sebelum simpan karena murah dan mudah dilakukan serta memberikan hasil yang baik.</em><em></em></p>

<p><em>Penelitian ini bertujuan untuk mengetahui pengaruh perlakuan pelapisan benih menggunakan bakteri Bacillus subtilis, Serratia marcescens, dan Pseudomonas kelompok fluorescens terhadap viabilitas dan daya simpan benih jagung manis (Zea mays saccharataSturt.). Penelitian disusun dengan rancangan petak tersarang (Nested Design) dengan petak utama adalah periode simpan minggu ke 0, 3, 6, 9, 12, 15, 18, 21, dan 24 dan anak petak adalah perlakuan coating dengan bakteri Bacillus subtilis, Serratia marcescens, Pseudomonas kelompok fluorescens, dan kontrol. Hasil penelitian menunjukkan adanya interaksi yang sangat nyata antara perlakuan coating benih dan periode simpan terhadap daya berkecambah, berat kering kecambah normal, kadar air, dan populasi bakteri. Perlakuan coating benih dan periode simpan menunjukkan interaksi yang nyata terhadap indeks vigor benih. Tolok ukur kecepatan tumbuh benihhanya dipengaruhi oleh faktor tunggal periode simpan. Benih yang dilapisi bakteri menghasilkan nilai berat kering kecambah normal yang nyata lebih baik daripada benih tanpa coating. Benih tanpa coating memiliki nilai daya berkecambah sebesar 56.7% pada periode simpan 24 minggu. Benih yang dilapisi bakteri Bacillus subtilis dapat mempertahankan daya berkecambah hingga 64.0% sampai periode simpan 24 minggu, sedangkan Serratia marcescens mampu mempertahankan daya berkecambah hingga 60.0% . Berdasarkan tolok ukur daya berkecambah, pelapisan benih menggunakan bakteri Bacillus subtilis dan Serratia marcescens merupakan perlakuan pelapisan benih yang potensial untuk lebih dikembangkan. Bakteri Bacillussubtilis lebih mampu bertahan hidup selama penyimpanan dibanding dengan bakteri Serratia marcescens maupun Pseudomonas fluorescens.  Populasi bakteri Bacillus subtilis sampai dengan periode simpan 24 minggu adalah 14.2 × 10⁴ cfu g^-1.</em></p>