The basic characteristics of 5 columns for high performance liquid chromatography (HPLC) and the mass spectra of phytohormones obtained by HPLC-mass spectrometry (LC-MS) were analyzed to use HPLC efficiently and to determine the optimum conditions for phytohormone analysis. In the case of HPLC, when the MeOH concentration (土20%) of the eluent (1 mL/min) was altered, the retention time became stable after 10 min. For 10 authentic standards of phytohormones, the retention time from 30 to 80% MeOH of an eluent was examined in 5 columns. In the octadecylsilane (ODS) type column, the sequence was zeatin (Z) / zeatin-riboside (ZR) → indole-acetic acid (IAA) → trans-abscisic acid (t-ABA) / indole-propionic acid (IPA) → ABA, and GA₃→ GA₇→ GA₄. In LC-MS, authentic standards and labeled ones of both IAA and ABA types showed almost the same changes in the mass spectrum patterns when the drift voltage increased, indicating the points where the fragmentation occurred. Optimum drift voltages for the highest intensity were 60 V for the IAA and ABA types, 40 V for GA₃ and 80 V for GA₄. Values of drift voltages at which molecular ions could be detected were up to 40 V for IAA, 80 V for ABA, 120 V for GA₃ and 140 V for GA₄.

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The Richards function can describe the cumulative frequency distribution accurately because the function has a high flexibility owing to the presence of the 4 functional parameters. Accordingly, the frequency distribution can be characterized by the 4 functional parameters. The parametrization was applied to the nitrogen release from coated urea and the growth of rice seeds with the passage of time. The Richards function accurately described these responses. For the analysis of nitrogen release, one of the 4 functional parameters reflected the nitrogen content of fertilizer, another one was calculated from the other parameters, and another one followed the Arrhenius equation. Accordingly, the nitrogen release from each type of coated urea at various temperatures could be characterized by 2 release parameters. Because the growth of rice seeds was too complex to be represented by the Arrhenius equation and the functional parameters were sensitive to a small deviation, the 4 functional parameters were transformed into 4 population parameters that were stable and comprehensive. Several factors affecting the growth could be analyzed using the population parameters although they may not affect the viability. Therefore, the analysis of nitrogen release and seed growth showed that the parametrization of the frequency distribution of responses using the Richards function could be applied.

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To contribute to the development of new integrated practices for the control of soilborne diseases, the relation between the development of bacterial wilt, a serious soilborne disease induced by Ralstonia solanacearum, and Ca nutrition in tomato (Lycopersicon esculentum Mill.) seedlings was investigated. Increased Ca concentrations in the nutrient solution reduced the disease severity in the seedlings of resistant cultivars, and decreased the populations of the pathogen in stems. This Ca-dependent resistance was also observed in susceptible tomato seedlings grafted onto rootstocks of a highly resistant cultivar. The resistance was affected by the Ca concentration after infection with the pathogen, but not before infection, suggesting that the Ca concentration in the cell walls before infection might not be directly involved in the Ca-dependent resistance. When varietal differences in the resistance and nutrient uptake by the seedlings were examined, highly resistant cultivars were characterized by a high Ca uptake. However, the differences in Ca uptake might not be related to the expression of the resistance, based on the results of experiments using mutually grafted seedlings of cultivars differing in resistance. Application of composts with various Ca concentrations reduced the disease severity, and the degree of reduction was correlated with the increase of the Ca uptake in shoots. These results indicate that the resistance of tomato to bacterial wilt is markedly affected by Ca nutrition of the host.

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Many hydrological observation stations for rainfall, pan evaporation and stream flow, etc. were installed by the Royal Irrigation Department for agricultural development. Collected data are processed in a mainframe computer and published in the form of a Water Year Book every year. However, many technicians prefer to consult hydrological data such as hydrographs and discharges on an individual basis. In order to promote the effective utilization of hydrological data, it is important that the data be available to the technicians at their station. Therefore, personal computer software for observed hydrological data suitable for the Microsoft Windows operating system was developed by the authors.

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In the single-truss system of tomato growing, the main shoot is pinched, leaving a few leaves above the first truss, and only the first truss is harvested. The objective of this system is to reduce labor requirement for training, pruning and harvesting. Workplace ergonomics is markedly improved by the use of high benches. There is no need for skillful plant operations. Soilless culture is required for the system, because several replantings are performed in a year. A “wet-sheet culture” system has been developed, in which a water-retaining sheet made of non-woven fabric is used as a growing medium. Fruit quality can be easily improved by the application of salinity stress. A large number of nursery plants are required in the single-truss system because of the dense planting and frequent replantings. Mass production of nursery plants in plug trays is recommended. In the single-truss system, no serious problems occurred even when very young plug seedlings were transplanted. An alternative way might be the use of cuttings. The roots of tomato plant cuttings emerge easily if the cuttings are placed in a medium such as rockwool. The single-truss system may be suitable for large-scale production of tomato. Continuous predictable production may be possible if the environment in the greenhouse could be adequately controlled.

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A simple preparation method was developed for tea-seed saponins (TSS) with improved quality. This method was applied to the preparation of TSS from 14 tea-seed cultivars. The yield of TSS was in the range of 10 ～ 13% per dry weight and not appreciably different among the cultivars. In addition, the antimicrobial activity of TSS against 6 yeast species was investigated. TSS showed a relatively high growth inhibitory activity against all the yeasts examined and their minimal inhibitory concentration (MIC) values varied from 0.08 to 1.20 mg/mL.

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It has been recognized that cattle are the main source of Escherichia coli O157:H7. This organism appears to be confined to the gastrointestinal tract and is shed in the feces. A probiotic product containing lactic acid-producing Streptococcus bovis LCB6 and Lactobacillus gallinarum LCB12 isolated from adult cattle was developed, and a preliminary experiment was conducted to evaluate its effect on the elimination of E. coli O157 from experimentally infected calves. Eight 4-month-old Holstein calves were orally challenged with E. coli O157 and the probiotic product was administered to 4 calves with continuous fecal shedding of E. coli O157 at 7 days after the infection. Fecal shedding of E. coli O157 was completely inhibited and re-shedding was not detected in any of the animals. Remarkable increase of the concentration of volatile fatty acids (VFAs), especially acetic acid in the feces after the administration of probiotic bacteria was correlated with the decrease in the number of E. coli O157. In the 4 calves in which fecal shedding of E. coli O157 had spontaneously stopped by the 7th day, a high concentration of VFAs was detected in the feces before and after the experimental infection. Although our results are preliminary and obtained from calves under limited conditions, the possibility of using a probiotic product to reduce fecal shedding of E. coli O157 from cattle was suggested.

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Preference tests and digestion trials of 4 different types of fronds of oil palm (Elaeis guineensis Jacq.), i.e. oven-dried form, pellets, silage and sodium hydroxide (NaOH)-treated silage, were carried out to analyze the influence of processing methods on the palatability, digestibility and voluntary intake in cattle. These processed oil palm fronds (OPFs) for digestion trials at maintenance level or under ad libitum feeding were mixed with a basal ration, mainly composed of palm kernel cake and fed to Kedah-Kelantan cross cattle. The digestibility of OPFs per se was calculated from the digestibility of the mixed ration and that of the basal ration. The results were as follows; the digestibility of OPF pellets was considerably lower than that of the other types of processed OPFs. However, OPF pellets had a high palatability and the dry matter intake (DMI) of the mixed ration, which includes OPF pellets, was higher than that of the other types of processed OPFs. These findings suggest that OPF pellets could be utilized as a silage additive to increase the dry matter content of crops with a high moisture level. The digestibility and DMI of ensiling OPFs were equivalent to those of oven-dried OPFs and the palatability of ensiling OPFs was high. Ensiling is the most suitable method to preserve OPFs at a low cost and can be recommended to farmers. NaOH-treated silage had a higher digestible DMI than the other types of processed OPFs, although it had a low palatability. It was confirmed that alkali treatment can effectively improve the nutritive value of OPFs. Therefore, introducing alkali treatment to the production of processed OPFs should be promoted if a safe and cost-effective method is to be developed.

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Three experiments were carried out to study the effects of feed characteristics on voluntary intake that was measured as dry matter intake (DMI) using 4 dairy cows offered timothy hay ad libitum. The digestibility depending on the chemical composition of timothy hay was determined using the total collection method in sheep, while the rate of fiber degradation in the rumen was calculated by the in vitro method. Mean daily DMI and DMI per metabolic body weight of 4 types of timothy hay ranged from 6.5 to 9.1 kg/day, and 56.9 to 78.8 g/kg^0.75, respectively. The daily DMI of timothy hay by dairy cows was closely related to the organic b fraction (Ob), sum of organic cellular contents and organic a fraction (OCC+Oa), and content of acid detergent lignin (ADL). The daily DMI could be predicted from the following regression equations; DMI = -0.18 x Ob + 19.5 (r=0.993), DMI = -0.50 x ADL + 12.1 (r=0.997), DMI = 0.19 x (OCC+Oa) -1.6 (r=0.993). In addition, the daily DMI of timothy hay by dairy cows was also closely related to the retention time in the rumen, digestibility depending on the chemical composition and rate of degradation of fibers in the rumen.

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In villages in Keerqin Sand Land, Inner Mongolia, China, desertification has been progressing severely for 30-40 years, resulting in poverty of the livestock farmers. A demonstration study has been carried out to increase the income and raise the villagers′ living standard through the prevention of desertification and the development of integrated farming combining animal husbandry and agriculture. Guidance on farm management was given to farmers in 5 model farms. In addition, Japanese voluntary helpers (JVH) have attempted to fix the moving sand dunes in close collaboration with the villagers to motivate the farmers to promote afforestation. Results of surveys on the development of these model farms and the effects of JVH work are as follows : 1) Development of model farms Effects of fences on model farms were so remarkable for controlling overgrazing that farmers harvested a large amount of hay. Since the production of maize, soybeans and rice with irrigation was successful, farmers obtained a high yield of grain which was consumed in their homes, sold to the market or used as feed for the animals. Consequently, the income of the model farmers was 3-5 times higher than that of the average village farmers. 2) Collaboration for the establishment of the “village forests” Collaboration was extended for the establishment of village forests, which were completed in 1998, and planting of apricot gardens began in 1999. 3) New land use system Reform on the land use system was promoted to utilize pastures collectively. It is considered that the collaboration extended by the authors and JVH based on a farmer participatory system contributed to village development by fostering a “self-help” approach among the farmers. Strategies to prevent desertification and for rural development are presented.

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