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Saprophytic and pathogenic behaviour of R. solani AG2-1 (ZG-5) in a soil amended with Diplotaxis tenuifolia or Brassica nigra manures and incubated at different temperatures and soil water content Abstract The Brassicaceae species Diplotaxis tenuifolia and Brassica nigra contain high concentrations of glucosinolates, the precursors of isothiocyanates (ITCs) that can have biofumigation effects in amended soils. In a laboratory experiment, incorporation of these plants as green manures into soil was expected to suppress Rhizoctonia solani AG2-1 (ZG5), the causal agent of damping-off in canola (Brassica napus). The manures were incorporated at 1 (1% w/w) or 5 (5% w/

The sensitivity of different forms of propagules of Rhizoctonia solani anastomosis group (AG)2-1/zymogram group (ZG)5 to volatile compounds produced in soil amended with green manure will influence the efficacy of green manures used to manage the disease. In laboratory experiments, we determined the impact of volatiles arising from residues of five species of Brassicaceae, and Avena sativa (oat), a non-Brassicaceae species, and volatiles of pure allyl isothiocyanate (AITC) or 2-phenylethyl isothiocyanate (2-PEITC) in either their soluble or vapour phase on the hyphal growth of R. solani arising from different propagules. The brassicaceous species were Brassica napus var. Karoo, B. napus B1, B. napus B2, B. nigra and Diplotaxis tenuifolia (a brassicaceous weed). Colony growth and hyphal density on water agar were measured up to 7 days. The amendment of a sandy soil with green manures at a high (100 g kg 21 , 10%) concentration generally suppressed the growth of the pathogen, but at a low (10 g kg 21 , 1%) concentration, the amendment had little effect on the radial fungal growth of the pathogen but increased the density of hyphae through more branching. The inhibition by volatiles from the residues of Brassicaceae species at 10% concentration was stronger (82-86%) than that by volatiles from oat (64%) amendment at the same rate. Hyphae arising from sclerotia and precolonised ryegrass seed were less sensitive than hyphae growing out of potato dextrose agar plugs. This indicates that thickpigmented cell walls may have protected the fungus from these unfavourable conditions. Pure AITC and 2-PEITC in the range of 0.5-2.0 mM inhibited the growth of R. solani from all forms of propagules, but hyphae originating from agar plugs were the most vulnerable compared with the two others. Thus, hyphae arising from the medulla of the sclerotia may be relatively tolerant to volatile compounds emanating from decomposing Brassica green manure amendments in the field and in vitro inhibition of the vegetative growth of the pathogen may not reflect its response to the amendments in the field.

<p>Endofit merupakan mikroorganisme (bakteri, jamur, atau aktinomisetes) yang hidup dan berkoloni di dalam jaringan inang tanpa menimbulkan efek negatif, bahkan banyak memberi keuntungan terhadap inangnya. Salah satu keuntungannya adalah sebagai agensia pengendali hayati baik untuk serangga hama maupun pa-togen penyebab penyakit tanaman. Sebagai agensia hayati, endofit dapat mengurangi kerusakan tanaman oleh serangga, nematoda, atau patogen penyebab penyakit melalui induksi ketahanan tanaman. Selain itu endofit juga dapat berfungsi sebagai agensia hayati melalui interaksi antagonis dan kompetisi. Dalam artikel ini akan dibahas kemampuan endofit sebagai agensia hayati serangga hama dan patogen; mekanisme yang berlang-sung; serta aplikasi endofit dalam dunia pertanian, khususnya tanaman perkebunan.</p><p> </p><p>Endophytes are recognized as microorganisms (bacteria, fungi, or actinomycetes), living and colonizing within host tissues without causing any harm, but giving many benefits to their host. One of the advantages is their role as biocontrol agents for insect pest or plant pathogen. As biocontol agents, endophytes could re-duce plant damage by insects, nematodes, and pathogens through induction for plant resistant mechanisms. Endophytes can also act as biocontrol agents through antagonistic and competition interactions. This article reviews the ability of endophytes as biocontrol agents for insect pest and plant pathogen, the mechanism, and application of endophytes in agriculture, particularly in estate crops.</p>

Shrimp culture is carried out by ponds in open areas, especially near coastal areas. The ponds water condition or water quality has a significant impact on the shrimp culture. There are also frequent problems among these shrimp ponds, such as crop failure caused by bad water quality. The water quality monitoring in shrimp ponds is often done manually by the farmer in periodical times. The water quality monitoring that is done manually tends to be impractical, requires high worker wages, and has a high human error rate. With the advances in the field of Information Technology, data may be retrieved through sensors and collected into a server. Then the data may be processed and visualized in order to support precision aquaculture using the Internet of Things (IoT). Precision Fish Farming (PFF) or precision aquaculture is a concept that applies control-engineering principles to aquaculture industries. The PPF concepts allow farmers to have the ability to monitor, control, and document biological processes in aquaculture farms. This research aims were to design and build a multi node sensor and master board to monitor water quality in real time using the prototyping method. The system consists of several sensors for monitoring temperature, pH, and salinity in shrimp ponds that are installed at each node. Nodes are actively sending data to the master board. This model is done to reduce the need for direct data access to the internet. The monitoring system is tested in PB Tunas Baru shrimps pond in order to check if the system may work properly. The sensor is set to retrieve pond water quality data every 5 minutes in a total 100 minute period. The result shows that the model works properly, and the means value of the total error rate for the salinity sensors, pH, and temperature sensors consecutively is 1.65%, 1.25%, and 0%. This information allows the farmers to maintain the water quality precisely in aim to produce high quality shrimp crops toward the precision aquaculture concepts.

Fenomena perubahan iklim terjadi karena aktivitas manusia dalam mengelola lingkungan, diantaranya adalah deforestasi, emisi gas dari kegiatan industri, dan pembakaran biomassa. Komponen iklim yang berubah, yaitu peningkatan suhu udara, konsentrasi CO2 dalam atmosfer, dan hujan berpengaruh terhadap tanaman tebu, serangga serta mikro organisme yang berasosiasi dengan tanaman tebu. Perubahan iklim lebih banyak menyebabkan pengaruh negatif terhadap tanaman tebu dan interaksi trofik antara tanaman tebu, serangga herbivora dan mikro organisme penyebab penyakit tanaman dan musuh alami herbivora maupun antagonis mikro organisme. Peningkatan suhu udara menyebabkan perubahan fisiologis pada tanaman tebu yang berakibat meningkatnya infestasi serangga herbivora dan infeksi patogen penyebab penyakit tanaman. Peningkatan komposisi CO2 dalam atmosfer menurunkan sistem ketahanan tanaman terhadap herbivora, sehingga dapat memicu terjadinya out break; dan berpengaruh positif, negatif, maupun tidak berpengaruh terhadap perkembangan penyakit tanaman. Perubahan iklim mengharuskan sistem pengelolaan serangga hama dan penyakit tanaman tebu untuk menerapkan aksi mitigasi maupun adaptasi perubahan iklim untuk memperoleh produksi tebu yang optimal dan sistem budidaya tebu yang berkelanjutan. Dalam tinjauan ini dibahas pengaruh perubahan iklim terhadap perkembangan serangga hama dan patogen penyebab penyakit pada tanaman tebu, serta strategi pengelolaannya. Kata kunci: penggerek tebu, luka api, tebu, perubahan iklim

<p>ABSTRAK<br />Tembakau bondowoso merupakan tembakau lokal rajangan yang<br />berkembang di Kabupaten Bondowoso, Jawa Timur. Saat ini ada delapan<br />kultivar dengan karakter produksi, mutu, dan ketahanannya terhadap<br />penyakit yang berbeda. Layu bakteri (Ralstonia solanacearum), busuk<br />batang berlubang (Pectobacterium carotovorum), dan lanas (Phytophthora<br />nicotianae) merupakan penyakit yang sering menyebabkan turunnya<br />produksi tembakau bondowoso. Evaluasi ketahanan delapan kultivar<br />tembakau bondowoso (Samporis, Serumpung, Marakot, Samporis Lokal,<br />Samporis AH, Samporis CH, Samporis B. Disbun, dan Deli) terhadap<br />ketiga patogen tersebut dilaksanakan di laboratorium dan rumah kasa Balai<br />Penelitian Tanaman Pemanis dan Serat (Balittas) mulai bulan April sampai<br />dengan Oktober 2011. Penelitian terhadap ketiga patogen tersebut<br />dilakukan secara terpisah. Masing-masing kultivar ditanam sebanyak 10<br />tanaman, 1 tanaman/polibag. Setiap perlakuan (kultivar) diulang 3 kali dan<br />disusun dalam rancangan acak kelompok (RAK). Inokulasi R.<br />solanacearum dan P. carotovorum dilakukan secara terpisah 24 jam<br />sebelum transplanting. Inokulasi P. nicotianae dilakukan dengan dua cara,<br />yaitu melalui akar dan pangkal batang. Inokulasi akar sama dengan cara<br />inokulasi bakteri. Inokulasi pangkal batang dilakukan pada tanaman<br />berumur 2 minggu setelah transplanting. Pengamatan intensitas penyakit<br />dilakukan setiap minggu selama 11 minggu. Hasil penelitian menunjukkan<br />bahwa kultivar Samporis CH, Samporis, dan Deli tahan terhadap P.<br />carotovorum, R. solanacearum, dan P. nicotianae. Kultivar Samporis CH.,<br />Samporis, dan Deli ketahanannya lebih tinggi terhadap ketiga patogen,<br />dengan intensitas penyakit berkisar antara 3,3%-6,7%. Kultivar Marakot<br />sangat rentan terhadap ketiga patogen tersebut dengan tingkat keparahan ≥<br />50%. Demikian pula kultivar Samporis AH yang rentan terhadap R.<br />solanacearum, P. nicotianae dan P. carotovorum dengan intensitas<br />penyakit 23,3-53,3%. Oleh karena itu, kultivar Samporis CH, Samporis,<br />dan Deli cocok dikembangkan pada lahan endemik penyakit tular tanah di<br />Kabupaten Bondowoso.<br />Kata kunci: tembakau  bondowoso, Pectobacterium  carotovorum<br />Phytophthora  nicotianae, Ralstonia  solanacearum,<br />ketahanan</p><p>ABSTRACT<br />Bondowoso tobacco is a local type of sliced tobacco which is<br />restrictedly cultivated in Bondowoso Regency, East Java. There are eight<br />cultivars known, ie. Samporis, Serumpung, Marakot, Samporis Lokal,<br />Samporis AH, Samporis CH, Samporis B. Disbun, and Deli with their own<br />distinctive characters on their production, quality, and resistance to<br />diseases. Bacterial wilt (Ralstonia solanacearum), hollow stalk rot<br />(Pectobacterium carotovorum), and blackshank (Phytophthora nicotianae<br />are the main cause of bondowoso tobacco production loss. Evaluation on<br />the resistance level of the cultivars to the three pathogens above has been<br />conducted at a laboratory and screen house scale in Indonesian Sweetener<br />and Fibre Crops Research Institute from April to October 2011. The<br />evaluation of each pathogen was conducted separately. Each evaluation of<br />the pathogen per cultivar used 10 plants planted individually in a polybag.<br />The experiment was arranged in a randomized block design with 3<br />replicates. R. solanacearum and P. carotovorum were separately<br />inoculated on the test plants 24 h before transplanting. The inoculation of<br />P. nicotianae was done twice via the root and stem. Disease intensity was<br />observed weekly for 11 weeks. The results showed that Samporis CH,<br />Samporis, and Deli cultivars were resistant to P. carotovorum, R.<br />solanacearum and P. nicotianae, whereas Samporis and Deli cultivars<br />were more resistant to the pathogens (disease intensity ranged 3.3-6.7%).<br />Marakot cultivar was very susceptible to all of the three pathogens (disease<br />intensity ≥ 50%). Similarly, Samporis AH cultivar was also susceptible to<br />the pathogens with disease intensity ranged 23.3-53.3%. The study<br />indicated that Samporis CH, Samporis, and Deli cultivars are suitable to be<br />cultivated in the endemic soil born pathogen areas of Bondowoso<br />Regency.<br />Key words: bondowoso  tobacco, Pectobacterium  carotovorum,<br />Phytophthora  nicotianae, Ralstonia  solanacearum,<br />resistance</p>

Kenaf fiber is mainly used for forest wood substitute industrial products. Thus, the kenaf fiber can be promoted as the main composition of environmentally friendly goods. Unfortunately, there are several Kenaf gardens that have been stricken with the disease-causing a lack of yield. By utilizing advances in technology, it was felt to be able to help kenaf farmers quickly and accurately detect which pests or diseases attacked their crops. This paper will discuss the application of the machine learning method which is a Convolutional Neural Network (CNN) that can provide results for inputting leaf images into the results of temporary diagnoses. The data used are 838 image data for 4 classes. The average results prove that with CNN an accuracy value of 73% can be achieved for the detection of diseases and plant pests in Kenaf plants.