It is generally recognized that inoculants (lactic acid bacteria: LAB) can be used as silage additives to improve the fermentation quality and to enhance animal performance. Especially in Japan, silage-making is a major technique to produce stored feeds and the amount of silage produced in recent years has accounted for about 70% of the amount of roughages produced in farms. Nevertheless in the Japanese environment, commercial inoculants are not always suitable for silage-making. In the present paper, at first, basic aspects of silage-making will be described in Sections 1, 2 and 3, and the problems associated with silage-making for cattle in Japan will be indicated in Sections 4 and 5. For the screening of LAB strains to develop inoculants suitable for silage-making in Japan, the construction of a model system for silage fermentation involving a solid mixed culture consisting of LAB, clostridia and coliform bacteria, referred to as “pouch method”, will be presented in Section 6, and the results of screening of LAB by using the pouch method in Japan and in Thailand will be introduced in Section 7. In Section 8, attempts to improve LAB strains isolated through screening by the cell fusion method and electroporation method will be discussed. Finally, aerobic spoilage of silage which is another major problem will be outlined in Section 9.

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The three-temperature (3T) model is used for estimating transpiration from only temperature and net radiation. Comparison with data from a weighing lysimeter showed that the 3T model is accurate. The objectives of this study were to confirm the main advantages, possible field applications, and accuracy of the 3T model over conventional models through theoretical analysis and experimental verification. Four commonly used transpiration models were chosen for comparison: Penman–Monteith (P–M), Bowen ratio, temperature difference, and ENWATBAL models. In a verification experiment conducted in a 1-ha sorghum field, microclimate, soil, and plant variables were extensively measured. The results showed that the 3T model has 4 main advantages. The major advantage is that it is theoretically sound, simple, and easily applicable, especially in developing countries. The next advantage is that aerodynamic resistance, surface resistance, and empirical parameters are not included. As a result, the transpiration process can be more easily revealed. The third advantage is that quantitative information on transpiration can be obtained with considerably fewer measurements, especially for application to remote sensing. The fourth advantage is that there is no fetch requirement. Because of these advantages, the 3T model could be applied both at small heterogeneous sites for local measurements and in large-scale fields for remote sensing. The transpiration estimated by the 3T model and the 4 conventional models was compared with lysimeter-measured data. The transpiration estimated by the 3T and P–M models agreed with the lysimeter-measured values. The mean absolute errors (MAE) between the measured value and the value obtained by the 3T model and between the measured value and that obtained by the P–M model were 0.45 and 0.42 mm d^–1, respectively. The MAE between the measured value and that obtained by the Bowen ratio model was 0.63 mm d^–1, between the measured value and that obtained by the temperature difference model, 0.69 mm d^–1, and between the measured value and that obtained by the ENWATBAL model, 0.88 mm d^–1. These results show that the MAE values of all the 5 models were < 1 mm d^–1, and the performance of the 3T model was as good as that of the conventional models.

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Analysis of the nucleotide sequence of the genome segment S5 of Rice gall dwarf virus (RGDV), which belongs to the genus Phytoreovirus, revealed that this segment encodes a putative protein of approximately 91 kDa. Antiserum raised against the protein reacted with a minor structural protein of similar size in RGDV, demonstrating that S5 encodes the structural protein of RGDV. The protein named P5 appeared to be a component of viral core particles. Although no overall homology was found to any other proteins, including those of animal-infecting reoviruses, P5 of RGDV exhibited a significant homology to P5 of Rice dwarf virus (50%), which might be a guanylyltransferase, and to P5 of Wound tumor virus (55%). These results, together with the observation that P5 bound guanosine triphosphate suggest that P5 of RGDV shows a guanylyltransferase activity and, moreover, that plant-infecting reoviruses have a similar functional and/or structural organization to that of animal-infecting reoviruses.

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To develop effective control techniques against mulberry anthracnose caused by Colletotrichum dematium, ecological and biocontrol studies on the disease were carried out. It was confirmed that the causal fungus overwinters mainly in infected mulberry leaves on the ground, then first infects the leaves adjacent to the ground in the rainy season. The fungal infection secondarily reaches the middle and upper foliage of mulberry trees with the passage of time, being less associated with the leaf age. The diseased leaves subsequently fall in autumn, and the fungus overwinters in these leaves again. It was suggested that the removal of fallen leaves from the mulberry field in autumn may contribute to cutting off the above disease cycle efficiently. A potential antagonist, Bacillus amyloliquefaciens strain RC-2, was isolated from healthy mulberry leaves. The antagonism was due to the production of antifungal compounds by the strain. Seven kinds of antifungal compounds were purified, and one of these was identified as iturin A2. Based on antagonistic mechanisms of the strain, the inhibition ability of RC-2 could be efficiently used by the application of the strain onto the leaves adjacent to the ground when primary fungal transmission from soil occurs. Furthermore, the antibiotics inhibited several other phytopathogenic fungi and bacteria, besides C. dematium, in vitro, suggesting that the antibiotics produced by RC-2 might be useful as multiple control materials against various plant diseases.

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Using a mixture of several primers, the suitability of multiprimer PCR for the early and simultaneous detection of various kinds of infectious microsporidia of silkworms was evaluated. As a result, specific DNA sequences were amplified by PCR using several primers designed for this study only when genomic DNA of the target microsporidia was used as the DNA template. However, no PCR products were obtained when genomic DNA of the silkworms or other microorganisms was used as the DNA template. In addition, specific DNA sequences were amplified by multiprimer PCR even when silkworms were infected with various kinds of microsporidia. When genomic DNA extracted from silkworm eggs infected with Nosema bombycis was used as the DNA template, the specific DNA sequences were amplified by multiprimer PCR. In addition, similar results were obtained even when genomic DNA extracted from silkworms infected with N. bombycis was used as the DNA template. These findings suggest that multiprimer PCR using several primers designed for this study is suitable for pebrine inspection of silkworm eggs.

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Acoustic emissions (AE) could be used as an indicator of plant water stress as “speaking plant”. The objective of this study was to observe the AE of tomato plant and to analyze the relationship between AE and plant water consumption associated with transpiration. Three glasshouse experiments were conducted with potted tomato plants. The AE, transpiration rate and “the plant transpiration transfer coefficient (h_at)” as an indicator of plant water stress level were determined with h_at being calculated based on sunlit leaf temperature, temperature of an artificial leaf without transpiration (hereafter,referred to as “non-transpiration leaf temperature”) and air temperature. The results showed that the daily patterns of the AE varied depending on the water stress level, which was indicated by h_at. Under mild or moderate water stress (h_at ≦0) conditions, the AE increased with the decrease in the amount of soil water but decreased with the decrease in the amount of soil water under severe water stress conditions (0 <h_at ≦1). To analyze the hourly changes in the relationship between AE and transpiration, the concept of “change of transpiration rate (AT)” was introduced. Under mild or in the absence of water stress conditions (h_at ≦0), AE increased linearly with the increase of AT with a significant regression coefficient (r² = 0.85 and slope = 0.61). Then, as the water stress level increased, the r² gradually decreased, as well as the slope of the regression line between AE and AT. When the water stress level increased further, the slope continuously decreased. However, r² started to increase gradually. Thus, when the water stress increased to a critical level (0 <h_at ≦1), a significant inverse linear relationship between AE and AT, with r² = 0.64 and slope = –0.73 could be observed. On the basis of these results, AE tended to be differently affected by AT depending on the water stress level.

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Plantations of single tree species which are usually set up to reafforest cleared lands in the tropics, have often been criticized for being associated with a low level of diversity in the ecosystems. However, our study of understorey plant species in various plantations of single exotic or indigenous species has shown that more plant species grew within stands near a natural forest than within grasslands in Sakaerat, northeastern Thailand. These forests contribute to the acceleration of the secondary succession from grassland, which before reafforestation was achieved by recurrent fires. In the natural regeneration of understorey tree species in planted forests, large tree species in the natural forest seem to be the major common seed source among the stands studied. The small leaf biomass in these planted forests generated enough shade to prevent the invasion of 2 fire-adapted competitive grasses and to provide a suitable light environment for seedling establishment at an early stage of forest development. These factors facilitated the establishment of other species within the plantations of single tree species. Faster-growing exotic species accumulated larger amounts of understorey biomass than indigenous species. The most suitable species was Acacia mangium. The association of forests planted with single tree species with a high species richness in the ecosystems may enable to achieve a high biological diversity at the landscape level, which could bring various benefits to the forests of Sakaerat.

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