Vesicular-Arbuscular Mycorrhizal (Varn) Activity in Acid Mn-Rich Soil

Acid soils are known as infertile soils as a results of nutrient deficiency such as P, Ca, Mo or toxicity by Al, Mn. Applying P fertilizer to these soils might not be affordable to farmers; therefore, mycorrhizal inoculation to such soils could be an alternative because these fungi can increase nutrient uptake especially P by associated plants. Liming is commonly practiced to improve fertility of acid soils since liming can increase soil pH, availability of nutrients such as Ca, P and alleviate toxicity by Al, Mn. Therefore, beneficial effect of liming on mycorrhizal fungi activity might be due to higher soil pH, better status of soil nutrients or alleviation of Al and Mn toxicity. A glasshouse experiment was conducted to evaluate the effects of soil pH or Ca amendment on vesicular-arbuscular mycorrhizal symbiosis in an acid Wahiawa soil with Leucaena leucocephala and Acacia mangium as indicator plants. At target soil solution P concentration of 0.02 mg L-1, Glomus aggregatum developed normally at soil pH ranges of 5.0-6.0. However, mycorrhizal effectiveness measured in terms of pinnule P content, nutrient uptake (except M n ) , and shoot dry weight attained highest values at pH 6.0 in leucaena and at pH 5.0 in acacia. In a second study in which I compared the effect of lime with that of gypsum, amendment of soil with gypsum at 0.02 mg P L-1 increased VAM colonization. However, VAM colonization was lower if soil was amended with gypsum rather than with lime. In leucaena, higher mycorrhizal effectiveness, nutrient uptake (except Mn), and shoot dry weight were observed in the limed soil than in the gypsum amended soil. However, these values were highest when acacia was grown in the soil amended with 0.32 mg Ca kg-1 soil. The lower VAM colonization and VAM effectiveness observed in leucaena and acacia grown in uninoculated soil probably reflect the inherently low infective propagules in the test soil. High P in soil caused suppression of mycorrhizal development. This is evidenced by lower VAM colonization in roots of leucaena and acacia grown in the soil with high P than in that with the lower P. The results of the present study suggest 2 approaches in order to maximize mycorrhizal activity in manganiferous acid soils. Firstly, soil pH must be raised to reduce Mn toxicity if acid tolerant host plants that are sensitive to Mn are to be grown. Secondly, further increase of soil pH to approximately 6.0 is required if acid sensitive host plants are to be grown. The present study did not succeed to separate the effect of H+, Ca+2 and Mn+2 on the effectiveness of mycorrhizal symbiosis. Therefore, further research needs to be conducted. Firstly, medium which is inherently low in Mn such as quartz sand, could be used to distinguish the effect of H+ from that of Mn+2. Secondly, Zero net charge soil which is low in Ca and Mn such as the Kapaa soil at a depth of 60-90 cm could be used to differentiate the influence of Ca+2 addition from that of H+, and Mn+2

Potensi Anggrek Dendrobium dalam Meningkatkan Variasi dan Kualitas Anggrek Bunga Potong

Dendrobium merupakan genus anggrek terbesar dari famili Orchidaceae. Genus anggrek ini merupakan kekayaan sumber daya genetik Indonesia yang banyak terdapat di kawasan timur, seperti Papua dan Maluku. Namun, sumber daya genetik tersebut belum dimanfaatkan secara optimal sebagai tetua dalam persilangan untuk menghasilkan keturunan yang memiliki karakteristik sesuai dengan yang diinginkan konsumen. Dari 20 seksi Dendrobium, barudua seksi yang digunakan sebagai induk silangan, yaitu seksi Phalaenanthe dan Ceratobium atau Spatulata. Kendala pengembangan anggrek di Indonesia antara lain adalah terbatasnya ketersediaan bibit unggul, teknologi yang digunakan masih sederhana, dan kurangnya dukungan kebijakan pemerintah

Respons Beberapa Varietas Nasional Gladiol Terhadap Pemupukan N Dan K

. Soedarjo, M. and S. Wuryaningsih. 2010. Response of Several Gladiolus Varieties on N andK Fertilizer Application. Nitrogen is one of the nutrients limiting the growth either vegetative or generative ofgladiolus, while potassium as a catalyst in the process of metabolism.A field experiment to evaluate the effect of Nand K fertilizers on the growth and development of three varieties of gladiolus was conducted at the experimentalgarden of The Indonesian Ornamental Crop Research Institute from June to December 2009. A split plot design withtwo replications was used. The main plot was three gladiolus varieties consisted of (1) Nabila, (2) Clara, and (3)Kaifa. The subplot was combinations of N and K fertilizers, namely (1) N10K10, (2) N10K20, (3) N10K30, (4) N20K10,(5) N20K20, (6) N20K30, (7) N30K10, (8) N30K20, and (9) N30K30. The Research results showed that there were interactionsbetween varieties and N K fertilizers on flower spike length and number of floret/spike. Nitrogen (N) and potassium(K), the macro nutrient that limits plant growth, and played a significant role in the quality of flowers and corms ofgladiolus, responses for each variety. Clara varieties was the most responsive to nitrogen fertilization, with fertilizerapplication of N30K10 produce longest flower stalks (73.16 cm), and highest number of class A corm (9.83). Fertilizerapplication N20K10 on Kaifa varieties produce the longest flower stalk and the largest flower number/spike. Nitrogenand Kalium fertilization could be implemented by considering the varity of gladiolus

Pengaruh Pupuk Anorganik dan Gandasil terhadap Pertumbuhan dan Hasil Umbi Porang (Amorphophallus muelleri Blume)

Seperti pada tanaman lainnya, pemupukan dengan NPK, hara makro dan mikro lainnya dimaksudkan untuk meningkatkan pertumbuhan dan hasil umbi porang. Unsur hara mikro biasanya diberikan dalam bentuk pupuk yang diberikan melalui penyemprotan, seperti Gandasil. Kajian dilaksanakan di rumah paranet dan bertujuan untuk mengetahui pengaruh pupuk NPK dan pupuk Gandasil terhadap pertumbuhan dan hasil umbi porang di tanah Alfisol. Kajian menggunakan dosis pupuk NPK + ZA dan kombinasi pupuk NPK + ZA dengan Gandasil sebagai perlakuan dan masing-masing perlakuan disusun dalam rancangan acak kelompok dengan 4 kali ulangan. Data dari semua parameter pengamatan dianalisis dengan menggunakan standar deviasi (SD) dari 4 ulangan. Hasil kajian menunjukkan bahwa tinggi tanaman dan diameter batang pada umur 25 hari setelah tanam (HST) dan 50 HST tidak dipengaruhi oleh pemupukan. Pemupukan dengan 200 kg NPK/ha dan 400 kg ZA/ha menghasilkan bobot kering daun, bobot kering batang, diameter umbi, ketebalan umbi dan bobot basah umbi porang tertinggi. Penggunaan pupuk Gandasil melalui tanah tidak diperlukan karena tidak meningkatkan pertumbuhan dan hasil umbi porang di tanah Alfisol

Potensi Anggrek Dendrobium dalam Meningkatkan Variasi dan Kualitas Anggrek Bunga Potong

Dendrobium merupakan genus anggrek terbesar dari famili Orchidaceae. Genus anggrek ini merupakan kekayaan sumber daya genetik Indonesia yang banyak terdapat di kawasan timur, seperti Papua dan Maluku. Namun, sumber daya genetik tersebut belum dimanfaatkan secara optimal sebagai tetua dalam persilangan untuk menghasilkan keturunan yang memiliki karakteristik sesuai dengan yang diinginkan konsumen. Dari 20 seksi Dendrobium, barudua seksi yang digunakan sebagai induk silangan, yaitu seksi Phalaenanthe dan Ceratobium atau Spatulata. Kendala pengembangan anggrek di Indonesia antara lain adalah terbatasnya ketersediaan bibit unggul, teknologi yang digunakan masih sederhana, dan kurangnya dukungan kebijakan pemerintah

Studi Pengaruh Substitusi Hara Makro Dan Mikro Media MS Dengan Pupuk Majemuk Dalam Kultur in Vitro Krisan

Studi substitusi hara makro dan mikro media Murashige & Skoog (MS) menggunakan pupuk majemuk untuk meningkatkan efisiensi kultur in vitro krisan (Dendranthema grandiflora) dilakukan di Laboratorium Kultur Jaringan, Kebun Percobaan Cipanas, Balai Penelitian Tanaman Hias (Balithi) dari Bulan Januari hingga Desember 2010. Aplikasi pupuk majemuk sebagai substitusi hara makro-mikro MS diharapkan dapat menurunkan biaya produksi benih melalui kultur in vitro, khususnya dalam penyediaan media tanam. Penelitian bertujuan untuk mengetahui pengaruh varietas dan kombinasi pupuk majemuk dalam meningkatkan efisiensi aplikasi kultur in vitro krisan. Varietas yang diuji ialah D. grandiflora cv. Dwina Kencana dan Pasopati, sementara pupuk majemuk yang digunakan ialah Hyponex Hijau (20:20:20), Hyponex Merah (25:5:20), dan Growmore (32:10:10) dengan komposisi uji (1) media ½ MS + 0,1 mg/l indole acetic acid (IAA) sebagai kontrol, (2) 1 g/l Hyponex Hijau + 0,1 mg/l IAA, (3) 2 g/l Hyponex Hijau + 0,1 mg/l IAA, (4) 3 g/l Hyponex Hijau + 0,1 mg/l IAA 0,1, (5) 1 g/l Hyponex Merah + 0,1 mg/l IAA, (6) 2 g/l Hyponex Merah + 0,1 mg/l IAA, (7) 3 g/l Hyponex Merah + 0,1 mg/l IAA, (8) 1 g/l Growmore + 0,1 mg/l IAA, (9) 2 g/l Growmore + 0,1 mg/l IAA, dan (10) 3 g/l Growmore + 0,1 mg/l IAA. Percobaan disusun menggunakan rancangan acak kelompok pola faktorial dengan tiga ulangan. Hasil penelitian menunjukkan bahwa jenis varietas dan media kultur berpengaruh terhadap keberhasilan kultur in vitro krisan. Varietas Dwina Kencana memiliki respons pertumbuhan yang lebih baik dibanding varietas Pasopati. Konsentrasi 3 g/l Hyponex Hijau yang ditambah dengan 0,1 mg/l IAA merupakan medium pengganti medium ½ MS terbaik yang mampu mendukung pertumbuhan eksplan pada Dwina Kencana maupun Pasopati. Pada umur 8 minggu setelah kultur, perlakuan tersebut memberikan rerata terbaik jumlah daun, jumlah nodus, jumlah akar, panjang akar, dan berat basah planlet. Aplikasi medium tersebut mampu menekan biaya penyediaan medium kultur per liter hingga 34,7% dibanding biaya penyediaan medium ½ MS yang mencapai Rp6.561,00 per liter. Aplikasi hasil penelitian ini memberikan dampak positif terhadap efisiensi biaya produksi kultur in vitro krisan, khususnya terkait dengan penyediaan media kultur

The Antioxidant Activities and Phenolic Content of Improved Soybean Seeds Varieties of Different Grain Sizes

Tempe and tofu are the main product of soybean commonly consumed as a daily food for the people of Indonesia. So far, soybean is well known to be a source of protein. Indeed, soybean contains secondary metabolites resulting in antioxidant activities. Antioxidants would nullify the negative effect of reactive oxygen and, as a result, could improve and maintain human health. Improvement of awareness of Indonesian people that soybean is good for human health promotion and maintenance could be a trigger to enlarge the soybean production area and increase national soybean production. The present study was undertaken to evaluate the total phenolic content and antioxidant activity of some improved soybean varieties. The observation was done in three replicates, and the standard deviation was made. The results of the present study showed that total phenolic content and antioxidant activity, as measured by ABTS and DPPH, varied among the soybean seeds tested. The variability of total phenolic content and antioxidant activity was not caused by different seed sizes but by the different genetic background encoding for other phenotypes than the seed size. In general, antioxidant activity is positively correlated to total phenolic content. Demas and Tanggamus showed significantly higher antioxidant activity compared to the rest, including imported soybean. Therefore, Demas and Tanggamus could be used as better food sources for human health

Perbandingan Teknik Inokulasi Puccinia horiana dan Seleksi Bakteri Antagonis untuk Mengendalikan Penyakit Karat Putih pada Krisan

Penyakit karat pada krisan (Dendranthema grandiflora) yang disebabkan oleh Puccinia horiana, merupakan kendala utama dalam budidaya krisan.  Kehilangan hasil krisan oleh patogen tersebut dapat mencapai 100%. Penelitian ini bertujuan (1) mendapatkan teknik inokulasi P. horiana yang efektif menimbulkan gejala penyakit dan (2) mendapatkan bakteri antagonis yang secara efektif dapat mengendalikan penyakit karat putih pada tanaman krisan. Penelitian dilaksanakan di Laboratorium dan Rumah Kaca Balai Penelitian Tanaman Hias (1.100 m dpl.) sejak Juni sampai  dengan Desember 2009. Penelitian terdiri dari dua kegiatan. Rancangan yang digunakan pada masing-masing kegiatan ialah acak kelompok dengan 11 perlakuan yaitu pustul karat direndam dalam air, pustul karat pecah direndam dalam air, pustul karat direndam dalam air disimpan 10oC 12 jam, pustul karat pecah direndam dalam air10oC 12 jam, pustul ditempel di atas daun, pustul pecah ditempel di atas daun, pustul ditempel di bawah daun, pustul pecah ditempel dibawah daun, tanaman plus pustul disimpan di samping tanaman uji disungkup, tanaman pustul pecah disimpan di samping tanaman uji disungkup, dan kontrol dengan tiga ulangan. Hasil penelitian menunjukkan bahwa metode inokulasi P. horiana  isolat yang paling efektif menimbulkan gejala penyakit karat putih pada krisan ialah perlakuan peletakan tanaman yang terinfeksi P. horiana  dengan pustul yang belum maupun telah pecah di samping tanaman sehat.  Dari hasil uji antagonistik diketahui bahwa isolat bakteri antagonis Corynebacterium-2, merupakan isolat yang paling efektif mengendalikan P. horiana. Kemangkusan bakteri antagonis tersebut dalam menekan P. horiana sebanding dengan fungisida sintetik berbahan aktif azoksistrobin 0,1%. Isolat Corynebacterium-2 berpotensi untuk digunakan lebih lanjut sebagai bahan aktif biopestisida yang efektif untuk mengendalikan penyakit karat putih pada krisan. Pegembangan biopestisida tersebut diharapkan dapat menekan penggunaan pestisida sintetik.White rust disease caused by P. horiana is one of the serious problems on chrysanthemum cultivation. The pathogen causes yield losses  up to 100%. The research was aimed (1) to determine the effective inoculation technique and (2) to select antagonistic bacteria  for effectively controlling the pathogen. The research was carried out  in the Laboratory and  Glasshouse of Indonesian Ornamental Crops Research Institute (IOCRI), from June to December 2009.  The research consisted of two experiments. Each experiments was arranged in a randomized completely block design with 11 treatments i.e. rust pustuls dipped in water, mature rust pustuls dipped in water, rust pustuls dipped in water and stored at 10oC during 12 hours, mature rust pustuls dipped in water and stored at 10oC during 12 hours, pustuls adhered on the leaf, mature pustuls adhered on the leaf, pustuls adhered beneath the leaf, mature rust pustuls adhered beneath the leaf, the plant + pustuls stored beside tested plants covered by transparent plastic, mature pustuls plants stored beside tested plants covered by transparent plastic, and control with three replications. The results indicated that the most effective inoculation technique for the pathogen was locating and infected plant with immature or mature pustuls  surounding  a healthy plant. The effective antagonistic bacteria against the pathogen was Corynebacterium-2. The effectiveness of  the antagonistic bacteria in suppressing P. horiana  was equivalent to synthetic fungicide  azoksistrobin 0.1%. The Corynebacterium-2 isolate will be potentially used as an active ingredient of biopesticide for controlling white rust disease on chrysanthemum. The development of the biopesticide is expected to decrease to utilization of synthetic pesticides

Growth response of pigeon pea (

As an archipelago country, Indonesia is surrounded by abundant saline soils which could be potential for growing food crops. The research work was conducted to study the growth responses of some pigeon pea genotypes on saline soils. The genotypes of Pigeon pea (LG Kidul, Mega, 90024, 91043 and 94028), as treatment, were grown on Alfisol soil (non-saline) and on saline soil. The experiment was carried out using completely randomized design and replicated three times. All data observed were analyzed by employing standard deviation from 3 replicates. The results of present research work revealed a significant growth retardation of pigeon pea when grown on saline soil. All growth parameters, plant height, plant diameter, root dry weight, and shoot dry weight were significantly lower on saline soil than on Alfisol soil. High concentration of Na+ was observed in roots, shoots and leaves of pigeon pea indicating growth retardation and toxicity symptoms of pigeon pea on saline soil was due to Na+