Microorganisms isolated from wheat leaf surfaces were screened for inhibition of wheat powdery mildew. A new screening method, in which wheat leaves were inoculated with Blumeria graminis f. sp. tritici and incubated with the cultured microorganisms under non-contact conditions, was developed in our study. Among these strains, a fungus designated as Kyu-W63 had an especially strong inhibitory effect. Kyu-W63 had a strong aromatic odor when being cultured. Nuclear magnetic resonance analysis revealed that Kyu-W63 produced two types of volatile substances, 5-pentyl-2-furaldehyde and 5-(4- pentenyl)-2-furaldehyde. Although the two are known to be nematicidal substances, the antifungal activity of 5-(4-pentenyl)-2-furaldehyde is first confirmed in our study. In contrast, 5-pentyl-2-furaldehyde was found to have strong suppression activities to various fungal species in this study, although it has been reported to suppress the growth of yeast, Nematospora coryli. Strain Kyu-W63 completely agreed with Irpex lacteus in the rDNA internal transcribed spacer (ITS) sequences, and strain Kyu-W63 was inferred to be I. lacteus. Biocontrol of parsley powdery mildew, caused by Oidium sp., was examined using a filamentous fungus, Kyu-W63 that produces antifungal volatiles, for 3 years under greenhouse conditions. Kyu-W63 treatment significantly inhibited disease severity compared to control plots. In addition, Kyu-W63 suppressed other harmful fungi such as Penicillium sp. and Aspergillus sp. which are plant pathogens or human allergens existing in the environment.

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The authors describe characteristics of boro rice fields of a village in Bangladesh. Boro rice fields in the village are classified by elevation into six types, of which three are characteristic and representative, namely char, khila and maath. The lowest fields classified as char are located on the fringe of bil and are not irrigated. High yield variety rice, which is short and needs a long growing period, cannot be cultivated in char. Fields classified as khila have the top layer of soil removed to expose the clay layer which has high water retention. The soil removed is heaped up around the field to form a bund which gives these fields a characteristic external appearance. Fields classified as maath are simple fields that are fallow land dug shallowly and surrounded by a short ridge which serves as a border for these relatively large plots. Large scale earth-moving work such as that required for khila is not needed for maath and rapeseed cultivation irrigated by a power pump is followed by boro rice cultivation. Reclamation of khila brought the consciousness that the irrigation water from bil is limited and should be shared, which reflects the traditional social relationship in the village. On the other hand, reclamation of maath, in which irrigation is realized by a power pump, introduced the consciousness that irrigation water is a purchasable and economical commodity

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The demand for fresh salad vegetables, such as iceberg lettuce, has increased worldwide in recent years. Numerous sanitizers have been examined for their effectiveness in killing or removing pathogenic bacteria on fresh produce. However, most of the sanitizers are made from the dilution of condensed solutions which involves some risk in handling and is troublesome. A sanitizer that is not produced from the dilution of a hazardous condensed solution is required for practical use. Electrolyzed water and ozonated water were investigated for bactericidal effects on fresh-cut produce as a convenient and safe alternative sanitizer. Although the efficacy of acidic electrolyzed water (AcEW) as a sanitizing agent was dependent on the kind of produce treated, AcEW could be sufficiently effective to offer an alternative solution to conventional sanitizers, such as sodium hypochlorite solution (150 ppm). A novel produce-washing procedure using a combination of alkaline electrolyzed water (AlEW), AcEW and mild heat demonstrated significant bactericidal effect compared with the treatment with ambient temperature. Besides the bactericidal effect, the progress of browning on lettuce was suppressed by using mild heat treatment. Furthermore, as a novel usage of AcEW, we examined the use of AcEW-ice for preserving vegetables. AcEW-ice inactivated the spoilage and pathogenic bacteria on lettuce and reduced the temperature of lettuce during storage.

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A CFD model was developed to simulate the air temperature and relative humidity distribution in greenhouses adopting fog-cooling systems using FLUENT. The developed model was validated using the data from a fog-cooling experiment in a single-span greenhouse without plants. The measured and simulated air temperatures varied from 0.1 to 1.4°C and the differences of relative humidity varied 0.3-6.0%. The validated model was then used to evaluate the design of a fog-cooling system in a multi-span glasshouse. The optimal system design was determined in terms of the cooling efficiency and the special uniformity of air temperature and relative humidity. The simulations demonstrated that the best performance of the cooling system occurred when the fog nozzles were located at the height of 2.3 m above the floor and at a distance of 1.9 m from the sidewalls with uniform row-to-row spacing of 3.7 m. The most effective location of the nozzles was within the air entry from the sidewall ventilator inlets of the greenhouse. However, it was important not to wet the sidewalls with the fog. This study suggested that the CFD model developed could be a useful tool to design and evaluate the fog-cooling systems in greenhouses with various configurations.

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Reddish fine sediment runoff from upland fields has been one of the causes of coastal environmental pollution in Okinawa, Japan. Planting grass strips is a well-known measure to reduce runoff of nonpoint-source pollutants from agricultural fields. In this study, we investigated the performance of a centipede grass (Eremochloa ophiuroides (Munro) Hack.) strip for reducing sediment runoff from an upland field in Okinawa, focusing on strip length and sediment aggregate size as factors affecting performance. Field experiments were conducted in field plots with a 4.0-m by 31.5-m bare source area on a Kunigami-Maji soil using three strip lengths (0.5, 1.5 and 3.0 m) under natural conditions. The sediment removal efficiencies were 24% for the 0.5-m strip, 36 to 54% for the 1.5-m strip and 73% for the 3.0-m strip. The strips trapped well the sediment aggregates larger than 0.02 mm in diameter, regardless of strip length. The longer strip trapped more aggregates of the 0.002-0.02-mm size class, which were dominant in the eroded sediment runoff from the plots. The strips poorly trapped aggregates smaller than 0.002 mm. The sediment trapping resulted primarily from deposition of sediment due to slowdown of surface flow.

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The effects of soybean by-products — soybean hulls (SH), soybean meal (SM) and raw soybean seeds (RSS) — on the rumen microbial population and fermentation were studied. The concentration of total rumen bacteria was greater (P = 0.06) for the SH and SM diets as compared to RSS. The concentration of cellulolytic bacteria tended to be higher with the SH and SM diets. Protozoal concentrations were significantly lower for the SH diet at feeding (T0, P < 0.05). Generic composition of protozoa was distinctly different among the soybean by-products. The composition of protozoa at T0 and 3 h (T3) for the SH diet group primarily consisted of vestibuliferids and Entodinium sp. with only 1% of protozoa from different genera present in the 6 h (T6) samples. The protozoa composition was more diverse with the SM and RSS diets, in that the “Others” types of entodiniomorphs included the genera Epidinium, Ophryoscolex, Metadinium, and Diplodinium. With the SH treatment, total VFA was greater and ruminal pH and acetate:propionate ratio were lower compared with the SM and RSS diets. Supplementation with all the soybean by-products modified both the microbial population and fermentation products and had an increased total dry matter intake in grazing dairy cattle.

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Adult emergence, oviposition and larval behaviors of the teak beehole borer (Xyleutes ceramica), a major pest moth of teak, were studied in the laboratory and the plantations in northern Thailand. Adult moths emerged mostly in March prior to the beginning of the rainy season. Females laid the greatest number of eggs on the first night after mating. Cumulative percentage of deposited eggs reached 79.2% on the 2nd night. The number of deposited eggs, which was estimated from weight, was 12,489 per female ranging from 3,666 to 21,094. A highly significant linear relationship existed between the numbers of eggs and the weight of an egg batch. Mated female longevity was 7 days on average. Eggs were laid in a mass mostly beneath the scales of bark of teak trunks in the field. An ovipositing female staying on a young teak tree in nature was also observed dropping her eggs to the ground. This is the first record of the finding of eggs and the oviposition behaviors of the moth in the field. Experimentally released larvae showed positive geotaxis both on the cut logs and on the living teak trunks. On the living teak trunks, larvae frequently changed their boring sites before June, but in early July, 37.5% of surviving larvae remained in the same boring sites as in the previous month and 78.6% in early August. All larvae settled down in particular boring sites in September. Control tactics for the teak beehole borer were also discussed in view of the oviposition behaviors.

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We measured the values for biomass and mean annual biomass increment (MAI) of planted forests in two parts of the Tropical Dry climatic zone (mean annual precipitation [MAP] < 1,000 mm) and in one site adjacent to one of the two parts and outside the Tropical Dry climatic zone to provide a comparison value for wet forests in the same region. MAI values of four planted forests averaged 2.60 (± 1.61 SD) Mg ha^-1 y^-1 at a MAP of 637 mm in the central dry zone of Myanmar. The MAI of exotic fast-growing tree species (Eucalyptus camaldulensis Dehn.) did not differ significantly from those of three native non-fast-growing tree species in the central dry zone of Myanmar. MAI values appeared to be lower on land with a high gravel content in the soil or with a higher degree of erosion. In the eastern part of Sumba Island in Indonesia, MAI of planted Tectona grandis L. forest equaled 3.76 Mg ha^-1 y^-1 at a MAP of 500 mm and 4.49 Mg ha^-1 y^-1 at a MAP of 1,500 mm. A Leucaena leucocephala de Wit stand produced a higher MAI (9.62 Mg ha^-1 y^-1) at a MAP of 500 mm. The MAI values for fast-growing tree species that we measured or collected in the Tropical Dry climatic zone were less than 20% of those recorded in the Tropical Moist and Tropical Wet climatic zones and about one-third the value for forests of non-fast-growing tree species. Accordingly, fast-growing tree species may not be capable of achieving their fast growth rates under the Tropical Dry climate. This information will be useful in developing land-use programs based on plantation forestry in dry forest areas.

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From the results of observations in Nong Saeng Village, Khon Kaen Province, Northeast Thailand from May 2002 to February 2005, precipitation was concentrated from evening to early morning in the middle of the rainy season. However, at the end of the rainy season, the concentration of precipitation during these hours decreased and the precipitation ratio in the morning increased. Extraordinary precipitation in the dry season had the same tendency as at the end of the rainy season. The frequency of gusty rain against all rain was lower than the frequency of the previous and following month during the middle of the rainy season. These results are a reference for development of water control systems and erosion control with cropping systems that are adjusted for precipitation patterns.

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Data from 174 non-irrigated farms in 50 tambons (sub-districts) in Khon Kaen Province, Thailand, taken by the Office of Agricultural Economics (OAE) on land area by type of agricultural use and income source by agricultural activity were combined with data from the Soil Survey Laboratory of the Land Development Department (LDD) on predominant soil types in each tambon. Farms were assigned to agricultural activity types based on combinations of primary agricultural income source (≥ 50% of total agricultural income) and secondary agricultural income sources (10-49% of total agricultural income). A diversification index was calculated as the sum of the number of primary and secondary income sources. Soils were characterized by texture, slope, drainage, and pH of each soil type. Six clusters of tambons were formed based on similarities among these variables. Three clusters contained 86% of the tambons: the rice-based farm cluster (31%), the field crop-based farm cluster (22%) and the cluster combining animal and vegetable-based production (33%). A fourth cluster (8%) combined field crop and animal production. The remaining two clusters (6% together) represented non-traditional and highly diversified farms, respectively. There was regional specialization in emphasis on rice (South) versus field crops (South Central, North), but tambons combining animal and vegetable production were distributed throughout all regions of the province. Tambons with heavier soils, less slope and poorer drainage had proportionally more land area in rice. These tambons also had proportionally more income from animal production. Conversely, tambons with lighter soils, more slope and better drainage had proportionally more land area in field crops and more income from field crops. Soil characteristics were not indicative of diversification. No spatial gradient either East-West or North-South was found for land use, income or diversification variables. Differences among clusters were more important than spatial differences. Stepwise regression indicated that six variables accounted for 76% of the variation in income. Three variables accounted for 65% of the variation in income: total land area (39% of variation), percentage of income from animal production (14%) and proportion of land area in field crops (13%). Three other variables contributed the remaining 11% of variation explained by the model: drainage (negative contribution); proportion of land area in other crops; and farms with their proportion of income from vegetable production greater than 50%. Animal production may be an indicator of potential for diversification-oriented research to increase the income contribution of horticultural production in farming systems.

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