Giyanto

Mekanisme Bakteri Endofit Mengendalikan Nematoda Pratylenchus brachuyurus pada Tanaman Nilam

Purwoceng ( Pimpinella pruatjan Molk.) berkhasiat aprodisiak dengan bahan aktif antara lain steriod, saponin dan ber-gaptin. Penelitian dilakukan di KP. Gunung Putri, bertujuan untuk menge-tahui hubungan cekaman defisit air dengan pembentukan bahan aktif penting pada purwoceng. Pada kegiatan penelitian ini dilakukan dua pengujian yaitu respon pembentukan bahan aktif terhadap peningkatan level cekaman defisit air pada tiga fase pertumbuhan tanaman (3, 5, dan 7 bulan), dan kandungan bahan aktif purwoceng pada kondisi tingkat ketersediaan air tanah di level 80% kegiatan lapang (KL), 60% KL, 50% KL, dan 40% KL, dengan meng-gunakan rancangan acak kelompok, 6 ulangan, pada intensitas cahaya 55%. Hasil penelitian menunjukkan bahwa periode cekaman defisit air berpengaruh terhadap pembentukan bahan aktif pur-woceng. Periode cekaman defisit air 21-38 hari berpengaruh terhadap kandung-an bahan aktif steroid, saponin dan bergapten. Periode cekaman defisit air selama 21-24 hari pada purwoceng berumur tiga bulan menghasilkan kan-dungan stigmasterol dan sitosterol ter-tinggi. Cekaman ringan dengan potensial air pada jaringan daunantara 5-12 bar menghasilkan kandungan bahan aktif steroid dan saponin tertinggi pada tujuh bulan setelah tanam (BST). Perlakuan cekaman defisit air selama 2 bulan dengan pengaturan ketersediaan air tanah setara 60% KL menghasilkan bahan aktif stigmasterol (0,121%), sitos-terol (0,087%) tertinggi pada tanaman purwoceng berumur lima bulan, sedang-kan empat bulan cekamans defisit air dengan 50% KL menghasilkan kandung-an saponin (0,149%) tertinggi pada umur tanaman tujuh bulan.Penyakit mosaik tercatat sebagai salah satu faktor pembatas dalam produksi tanaman nilam ( Pogostemon cablin ). Penelitian ini dilakukan untuk mengukur pengaruh infeksi virus penyebab penyakit mosaik terhadap produksi dan kadar minyak tanaman nilam. Bahan yang digunakan dalam penelitian ini adalah tiga varietas unggul tanaman nilam yaitu Sidikalang, Lhokseumawe dan Tapak Tuan. Infeksi Potyvirus berhasil dideteksi pada varietas Tapak Tuan dan Lhok-seumawe berdasarkan hasil metode ELISA. Pengukuran berat terna basah, terna kering, kadar minyak dan kadar patchouli alcohol (PA) yang dilakukan pada tanaman berumur enam bulan menunjukkan terjadinya penurunan produksi dan kadar minyak. Penurunan tertinggi berat terna basah, terna kering, kadar minyak dan kadar PA berturut-turut dapat mencapai 34,65, 40,42, 9,09 dan 5,06%.Pengaruh pemupukan terhadap intensitas serangan penyakit budok, dan pertum-buhan tanaman nilam telah dilakukan di daerah endemik penyakit budok di Nagari Situak Pasaman Barat sejak Juli 2009 sampai Maret 2010. Perlakuan disusun dalam Rancangan Acak Kelompok 8 perlakuan dan 4 ulangan. Perlakuan yang diuji adalah pupuk NPK (PL) 250 kg/ha, pupuk kandang (Po) 20 t/ha, kompos nilam (Kn) 10 t/ha, kombinasi (PL + Po), (PL + Kn), (Po + Kn,) (PL + Po + Kn) dan kontrol (tanpa pupuk). Hasil pene-litian menunjukkan bahwa semua perla-kuan memberikan pengaruh positif dalam menekan serangan penyakit budok, pem-berian pupuk NPK 250 kg/ha + pupuk kandang 20 t/ha + kompos nilam 10 t/ha mampu menekan intensitas serangan budok sekitar 48,49% dan menghasilkan pertumbuhan tanaman lebih baik dibanding perlakuan lain dengan rataan tinggi tanaman 96,83 cm, jumlah cabang primer 27,50 buah, diameter tajuk 104,98 cm dan produksi terna 1187,50 g/rumpun, hasil ini tidak berbeda nyata dengan pemberian pupuk kandang 20 t/ha + pupuk NPK 250 kg/ha dan pemberian pupuk kandang 20 t/ha + kompos 10 t/ha, tapi berbeda nyata dengan perlakuan kontrol dengan rataan tinggi tanaman 69,58 cm, jumlah cabang primer 19,50 buah, diameter tajuk 65,27 cm dan produksi terna 552 g/rumpun.

Seleksi dan Identifikasi Bakteri Antagonis sebagai Agens Pengendali Hayati Penyakit Hawar Pelepah Padi

Research was carried out in a screen house at Indonesian Center for Rice Research and in the rice field at Pati, Central Java, during the Wet Season 2009. Design of each experiment was factorial with three replications. The first factor consisted of four varieties, namely IR74, Ciherang, Hipa 4, and Muncul. The second factor consisted of three insecticides, namely imidackloprid, BPMC, and deltamethrin. Results of the screen house trial showed that varieties IR74 and Ciherang were able to reduce nymph population of brown planthopper (BPH) biotype 4 generation 1 (G1) from Pati, Central Java, by 52.9% and 19.1%, respectively. Variety IR74 reduced nymph population of BPH biotype 4 generation 2 (G2) by 39.8%. The Insecticides Effectiveness (IE) values of imidakloprid, BPMC, and deltamethrin treatments at dosages 0.5 kg/ha; 1.5 l/ha, dan 0.25 l/ha, respectively, against BPH Biotype 4 Generation 1 (G1) and Generation 2 (G2) were less than 50%. Insecticides imidacloprid, BPMC, and deltamethrin each was not effective against the BPH. On the other hand, IE of imidacloprid, BPMC, and deltamethrin at the recommended dosages to BPH biotype 1 G1 in he screenhouse were 99.8%; 50.6% and 24.7%, respectively. Results of the field trial in Pati showed that varieties IR74, Ciherang, Hipa 4, and Muncul prior to 65 days after transplanting (DAT) did not reduce the BPH populations, but at 75 DAT, varieties IR74 and Ciherang reduced the BPH populations up to 52.3% and 66.1%, respectively. Decrease in the BPH population by imidacloprid ranged from 20.1-52.4% and by BPMC from 9.2-26.4%. Yield of IR74 which resistant variety to BPH Biotype 3 was significantly higher than that of Ciherang with a yield different of 3263 kg/ha.Insufficient P is a limiting factor for rice production. Tolerant varieties to deficiency P are very important to solve the problem. The objective of the experiment was to evaluate rice genotypes to P deficiency and its interaction to Al toxicity. The experiment was conducted at the green house of ICABIOGRAD (Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development) in WS 2006, using Yoshida solution. Molecular analysis was conducted in 2010 to observe the effectiveness of gene Pup1 segment in upland rice varieties to be compared with Kasalath tolerance variety from India. Plastic box of 10 ltr, containing solution as media was used in the experiment. The treatments were arranged in a split-split plot design with three replications. Treatments were two levels of Aluminum (0 and 45 ppm Al) as a main plot, and 4 levels application of P fertilizer (0, 0.5, 5.0, and 10 ppm P) as sub plots, and sixteen upland rice genotypes as sub-sub plots. Results showed that there were interactions between P, Al treatments and genotypes to characters which were observed. Application of P up to 10 ppm P increased plant height, number of tillers, shoot dry weight, and root dry weight significantly, but not for root length. The effects of aluminum were decreasing in plant height, shoot and root dry weight and root length significantly, but not for number of tillers. Evaluation of tiller number for P deficiency treatment showed three cultivars were tolerant to P deficiency, namely: Way Rarem, Limboto and Sentani, and five genotypes were moderately tolerant: Way Rarem, Jatiluhur, Sentani, K36-5-1-1, Limboto, dan NIL-C443. Genotypes indicated tolerant to both Al toxicity and P deficiency, were Way Rarem, Jatiluhur, Sentani, K36-5-1-1, Limboto, dan NIL-C443. There were no correlation between rice tolerance to P deficiency with rice tolerance to aluminum toxicity. Molecular analysis using Pup1 specifik primers showed fully Pup1 segment on NIL-C443, K36-5-1-1, Jatiluhur, Limboto, Silugonggo, Way Rarem and those genotypes showed tolerance or moderately a tolerant to P deficiency, except for Silugonggo.The number of improved red rice varieties (red color caryopsis) is still limited, namely Bahbutong and Aek Sibundong. Red rice is useful as functional food due to its antocyanin content which have a potential function as antioxidant. The research was aimed to study the effect of processing (milling and cooking) on the thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), and pyridoxin (vitamin B6) content of new varieties, local red vareties and advanced lines of red rice. The materials used in the experiment were two red rice advanced lines, local red rice (Jembar Beureum and Jatiluwih), red rice improved variety Aek Sibundong, and white rice variety Ciherang. Results showed that milling and cooking processes reduce thiamin, riboflavin, niacin , and pyridoxin contents on advanced improved red lines, red improved variety, local red varieties and Ciherang white improved variety. Jembar Beureum milled and cooked rice had the highest thiamin and niacin content. Jatiluwih milled and cooked rice had the highest riboflavin and pyridoxin content. Local red rice had higher vitamin B content than improved red advanced lines, Aek Sibundong and Ciherang white rice. Local red rice varieties may be used as parent material on the breeding program to develop red rice improved varieties with higher vitamin B content.Research on the effect of packaging material for aromatic rice quality and its life storage was carried out. The aromatic rice varieties i.e Pandanwangi, Sintanur and Mentikwangi (each 750 kg) were dried in box dryer at 45oC for 12 hours. The dried paddy was milled at commercial milling to produce milled rice. The milled rice then were packed in high density polypropylene (HDPP), super bag and plastic sac. Factorial treatments were arranged in a completely randomized design, replicated thrice. The first factor was aromatic rice varieties (Sintanur, Mentikwangi and Pandanwangi) and the second factor was packaging material (superbag, high density polypropylene (HDPP) and plastic sac). Each treatment consisted of 5-7 kg of milled rice, kept in the room condition for six months. The physical, chemical characteristic, organoleptic test, and flavor composition were observed at the beginning, the middle and the end of storage. The result showed that physical quality of rice decreased parallel with the duration of storage. The whiteness, transparency and milling degree of rice kernel decreased as the period of storage increased. The infestation of insect in storage was found at 60 days after storing (at the second month) and tended to decrease parallel with insect life cycle. The used of plastic sac as packaging was invested by insect more than those of super bag and high density polypropylene. Therefore plastic sac was not recommended for packaging of aromatic rice at room condition. Organoleptic test indicated that cooked quality of aromatic rice decreased parallel with storing time. Based on colour, aroma, taste and texture, aromatic rice should be consumed within 90 days. After 90 days, the colour, aroma, taste and texture of the cooked rice was less preferred by panelis. The uses of plastic sac to pack aromatic rice produced cooked rice less preferable than those of super bag and high density polypropylene plastic.