Teknik Aplikasi Trichoderma SP. Terhadap Pertumbuhan Dan Hasil Tanaman Kentang (Solanum Tuberosum L.)

Tujuan dari Penelitian ini ialah untuk mengetahui interaksi konsentrasi dan waktu aplikasi Trichoderma sp. terhadap pertumbuhan dan hasil tanaman kentang (Solanum tuberosum L.). Penelitian ini dilaksanakan di Kebun Percobaan Cangar, Fakultas Pertanian Universitas Brawijaya berada di Desa Sumberbrantas, Kecamatan Bumiaji, Kota Batu pada ketinggian tempat 1650 mdpl. Penelitian ini dilaksanakan pada bulan Mei sampai Agustus 2012. Penelitian ini menggunakan Rancangan Petak Terbagi (RPT) Faktorial yakni dengan dua faktor. Faktor pertama sebagai petak utama ialah konsentrasi Trichoderma sp. cair terdiri atas T1: konsentrasi 5 ml.l-1, T2: konsentrasi 10 ml.l-1. Faktor kedua sebagai anak petak ialah waktu aplikasi Trichoderma sp. cair terdiri atas W0: aplikasi sekali, W1: aplikasi 2 hari sekali, W2: aplikasi 4 hari sekali, W3: aplikasi 6 hari sekali, W4: aplikasi 8 hari sekali. Terdapat 10 perlakuan kombinasi dengan setiap perlakuan diulang sebanyak tiga kali dan diperoleh 30 petak percobaan. Berdasarkan hasil percobaan terdapat interaksi nyata antara konsentrasi Trichoderma sp. dan waktu aplikasi terhadap saat muncul serangan penyakit hawar daun, namun tidak berpengaruh nyata terhadap pertumbuhan dan hasil umbi kentang. Hasil bobot umbi kentang tertinggi pada konsentrasi Trichoderma sp. 10 ml l-1 dengan waktu aplikasi delapan hari sekali (T2W4) ialah 2,34 ton ha-1

Characterization of Bacterial Pathogen Causing Wilt and Leaf Blight on Corn (Zea Mays) by Physiological, Biochemical and Molecular Methods

In 2011, we found a new bacterial disease characterized by wilt, dwarf and blight symptoms on sweet corn in Batu, East Java, Indonesia. The objective of this study is to characterize the causal agent of the disease. In this study, several assays were conducted, including hypersensitive response, pathogenicity, physiological and biochemical characteristics, PCR detection using two specific species primer pairs for Pantoea stewartii pv. stewartii, and homology analysis of 16S rRNA gene sequence. Four Gram-negative, non-motile, facultative anaerobic bacteria were isolated from the diseased tissue. Only two strains, BD1 and BB2, gave positive result in hypersensitive reaction, pathogenicity, and Koch\u27s postulate assays. BB2 and BD1 strains also showed positive results in the PCR amplification using specific primers derived from the P. stewartii subsp. stewartii 16-23S gene region of but showed negative result when using primers derived from P. stewartii subsp. stewartii hrpS gene region. Sequence of partial 16S rRNA gene of BD1 and BB2 showed highest homology at 96% to P. stewartii subsp. stewartii strain ATCC 8199 (NR. 044800.1). This results suggest that bacterial pathogens isolated from sweet corn in Batu were strains of Pantoea spp

Identification of Bacterial Wilt and Leaf Blight Disease on Maize (Zea Mays) Found in Kediri, Indonesia

Recently, a new bacterial disease of maize (Zea mays) was observed in Kediri, East Java, Indonesia. Infected plants showed wilt symptoms occasionally accompanied by leaf blight. This study aims to characterize the causal agent of bacterial wilt and leaf blight of maize observed in Kediri. Gram-negative, facultative anaerobic bacteria were isolated from the diseased tissues. All bacterial strains (KD1A, KB2A, KD1, KD4, KB1) gave positive result both in the hypersensitive response and pathogen-nicity assays. However, only KD1 and KB1 strains could be re-isolated from the diseased tissues. Based on several physiological and biochemical assays, the bacteria resembled Pantoea agglomerans. Moreover, the strains showed negative result on PCR amplification using HRP1d and HRP3r, a primer pair specific for detection of P. stewartii subsp. stewartii. Analysis of 16S rRNA gene sequence of KD1 and KB1 showed highest homology at 88% and 90%, respectively to P. agglomerans strain DSM 3493 (NR 0419781). The homology values were too low to conclude that the bacteria were similar to P. agglomerans. These results suggest that bacterial pathogens isolated from maize in Kediri were strains of Pantoea sp

The Potency of Bacillus SP. and Pseudomonas SP. as Biologicalcontrol Agents Against Corn Leaf Blight Disease Caused by Pantoea SP.

One of new biotic constraints in corn production in Indonesia is leaf blight disease caused by Pantoea sp. which is needed to be controlled. The purpose of this research is to study the potential of Bacillus sp. and Pseudomonas sp. as biological control agents against corn leaf blight caused by Pantoea sp. The results showed that all bacterial strains of Bacillus sp. and Pseudomonas sp. have potential in inhibiting the growth of Pantoea sp. by showing the clear zone on the agar plate. The antibiosis types are bactercide or bacteriostatic. On pot experiment all bacterial strains showed the reduction of the disease incidence at the same level compared with that of bactericide streptomycin suphate. All bacterial strains as well as bactericide could reduce the disease incidence at 18-24% compared with that of control (aquades treatment only). The results suggest that all bacterial strains are potential as biological control agent against leaf blight disease on corn leaf caused by Pantoea sp

The Influence of Environmental Factors to the Abundance of Scales (Hemiptera: Diaspididae) Population on Apple Crop

This research aims to assess the environmental factors that affect the abundance of scales populations on the apple crop. The study was conducted in July 2012 to January 2013. The study was conducted at two sites with different altitude. Bumiaji village's altitude is ±900 m and Tulungrejo village's altitude is ±1,515 m asl. Multiple linear regression analysis was conducted to determine the environmental factors that affect the abundance of scales populations on the apple crop. Based on the results of the regression analysis, air temperature and humidity affect the abundance of scales populations in Binangun while rainfall and long solar radiation have no effect. Scales population abundance of the apple crop in Binangun was influenced by air temperature and humidity one week before. Based on the results of the regression analysis, air temperature, air humidity and rainfall affect the abun dance of scales population in Tulungrejo while long solar radiation has no effect. Scales population abundance ofthe apple crop in Tulungrejo was affected by air temperature two weeks before, while humidity and rainfall were affected one week before. The higher air temperature scales, flea population level will increase. And the higherrelative humidity, scales population levels will increase

The Increase of Arthropods Biodiversity in Paddy Field Ecosystem Managed by Using Integrated Pest Management at South Borneo

We have studied the arthropods biodiversity in two paddy field ecosystems, namely, paddy field ecosystem using Integrated Pest Management (IPM) system and non-IPM paddy field ecosystem. This study was conducted from April 2011 - November 2011 in three locations, that is, Pasar Kamis village and Sungai Rangas village in Banjar regency, and Guntung Payung village in Banjarbaru city, South Borneo Province. In this study, we used insect nets, yellow sticky traps, light trap and pitfall trap to get the sample or catch the arthropods in one period of planting season. The arthropods caught were then classified into some classes: pest (herbivore), natural enemy (parasitoid and predator), and other arthropods. After that, the Species Diversity Index was determined using its Shannon-Wiener Index (H), Evenness (e), Species Richness (R), and Species Similarity Index (IS). The sum of arthropods which have the characteristic of pest and parasitoid were higher in the IPM paddy fields than in the non-IPM paddy fields, and the sum of other arthropods were the same. The highest H and e values were in the IPM paddy field in Pasar Kamis village. The IS value for each three locations were 77.5% in Pasar Kamis village, 93.42% in Guntung Payung village, and 78.76% in Sungai Rangas village

Study of Arthropod Communities in a Virginia Tobacco Agro-Ecosystem

The cultivation of tobacco is one of users of agro-chemical substances such as insecticides, herbi-cides, defoliants, and fertilizers among other food crops and plants with high economical value. The use of these chemicals may bring negative effects regarding the richness and abundance of arthropods. The study of arthropod community in the Virginia tobacco ecosystem was carried out in Central Lombok, West Nusa Tenggara Province, during the 2010 plantation year. It was aimed at finding the composition, structure, and dynamic of the arthropod diversity around the tobacco field. Samples were obtained by using trapping techniques (pitfall traps, yellow-pan traps, and sweep net). The number of arthropods found in Virginia tobacco field are 69, consisting of 65 species of insects (belonging to 46 families and 8 orders) and 4 species of spiders (belonging to 4 families). The majority of insects found was Hymenoptera, dominated by bees. Based on the ecological functions, the major group of arthro-pods documented was phytophagous (20 species), mostly Coleoptera and Orthoptera. Yet, the number of predators was relatively more abundant than that of the phytophagous. The number of kinds of ar-thropods commonly interacting around the field fluctuated during the growing period, while in the cultivation period the number decreased. The diversity of the species (H) and the ratio of abundance of the natural enemies and phytophagous in the field was high