Showing papers in "Jarq-japan Agricultural Research Quarterly in 2000"

Isolation of Bacteria Producing Bluish-Purple Pigment and Use for Dyeing

Abstract: Janthinobacteriun lividum was isolated from wet silk thread whose color became bluish-purple 7• 8). This bacterium produced large amounts of bluish-purple pigment on some media containing amino acids, such as Wakimoto medium. The pigment was extracted with methanol and was identified as a mixture ofviolacein and deoxyviolacein. This pigment could be used to dye not only natural fibers like silk, cotton and wool, but also synthetic synthetic fibers like nylon and vinyl on, and generally gave a good color tone. The shade depended on the material. Silk, cotton and wool showed a bluish-purple color, nylon a dark blue color, and acetate a purple color. Dyeing could be performed by a simple procedure consisting of either dipping in the pigment extract or boiling with the bacterial cells. By changing the dipping time and the temperature of the dye bath, shades ranging from light purple to deep bluish-purple could be selected. The color fastness of the dyed material was about the same as that materials dyed with vegetable dyes, but the color faded easily when the material was exposed to sunlight. However, since the pigment can be mass-produced by culturing, if these shortcomings could be overcome, the dye may become promising. The pigment displayed an antimicrobial activity against phytopathogenic fungi like Rosellinia necatrix which causes white root rot of mulberry 7). It could also be used as a bio-fungicide. Discipline: Sericulture Additional key words: Janthinobacterium lividum, violacein, natural pigment, bluish-purple color

What are stingless bees, and why and how to use them as crop pollinators?: A review

Abstract: The efficiency of insects as crop pollinators depends on their biological characteristics in relation to the crop and the environment in which they are needed. For glasshouse pollination in Japan, stingless bees are potentially promising pollinators for the following reasons: they are harmless to beekeepers and glasshouse workers, they visit a wide range of crops (polylecly), they are tolerant of high temperatures, they are active throughout the year, they can be transported easily, and they do not pose an environmental risk by escaping and invading natural habitats as they would not survive the Japanese winter. There are still, however, some limitations to using stingless bees in such areas, one of which lies in how to improve methods for propagating and maintaining the colonies throughout the year. To address this prob! em we suggest the development of a new type of hive box. Discipline: Crop production I Horticulture Additional key words: beekeeping, meliponiculture

Development of fully automatic vegetable transplanter.

Abstract: We developed 3 models of riding-type, fully automatic vegetable transplanters. These prototypes are suitable for cell mold seedlings and pulp mold cell pot seedlings, mainly of leaf vegetables such as cabbage, Chinese cabbage, and lettuce. The prototypes enabled continuous transplanting work on 2 rows simultaneously, a planting speed of 60 cells/row/min, with vegetable seedlings fed automatically. The transplanting accuracy, in terms of the rate of misplanted hills, was 3% or less, and the working capacity per worker was approximately 10 a/h. We estimated that the annual coverage area of this machine for cultivating cabbage is 53 ha/year, and the minimum economically suitable area for use is 8.2 ha. Based on these prototypes, transplanters have been put on the market by several companies and are now being used in various areas. In this study, we presented a draft of the standards for seedling trays, such as cell mold seedling trays and pulp mold cell pots (paper pots), for possible use of a fully automatic vegetable transplanter. At present, 4 million or more trays are supplied to the market. Discipline: Agricultural machinery Additional key words: transplanting, machine, seedlings, cabbage, lettuce

Detection of crop transpiration and water stress by temperature-related approach under field and greenhouse conditions.

Abstract: A new method for estimating crop transpiration and crop water stress index (CWSI) by using a temperature-related approach was developed and verified this study. In the proposed method, 3 temperatures and a few meteorological variables (net radiation and humidity) are required. The 3 temperatures include sunlit leaf temperature, imitation leaf temperature, and air temperature. The imitation leaf refers to an artificial leaf without transpiration. The major advantage of the proposed method is that plant correction factors, empirical coefficient, and canopy and aerodynamic resistances are not required. Experiments for verification were conducted in a sandy field with sorghum crop and in a greenhouse with melon crop. Data obtained by the proposed method were compared with the amount of transpiration determined with lysimeters, soil water status determined by TDR, and CWSI estimated by Jackson’s method. The calculated transpiration by the proposed method was consistent with the results obtained with lysimeters, with regression coefficient 12=0.88. Values of CWSI calculated by the proposed method were in agreement with Jackson’s CWSI, with a regression coefficient approximately equal to 1. These results indicate that the proposed method can be applied to estimate crop transpiration and water stress index under both field and greenhouse conditions. Discipline: Agro-meteorology Additional key words: imitation leaf, sorghum, melon

Biology and control of the citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera : Gracillariidae) in Japan

Abstract: Recent advances in research on the life history, natural enemies, sex attractant, and practical control of the citrus lceafminer (CL:M) in Japan are described, Adult CLM overwinters within canopies of the citrus trees in the warmer districts of the citrus belt where the overwintering females begin to oviposit in mid-March. The moth passes 9 to 10 and 5 generations per year in the southwestern and northeastern parts of the citrus belt, respectively. Developmental zero and effective heat units for development from egg to adult emergence are 12.1°C and 206 degree-days, respectively. Eighty per cent or more larvae were killed by parasitoids and unknown factors before pupation during the summer-autumn seasons. Dominant parasiwids are Sympiesis striatipes in m ainl and-Japan and Cirrospilus ingenuus and Citrostichus phyllocniswides in the Southwestern Islands. Biological control of CLM by native parasitoids is not sufficiently effective in Japan because Ageniaspis citricola, a most effective biological control agent in tropical Asia, has not been detected in Japan. A sex attractant, (Z, Z)-7, 11-hexadecadienal showed a high activity for male moths in Japan, but was ineffective for those in foreign countries. The sex attrac tant appeared to be useful for the forecasting of seasonal occurrence, and control measures by using this substance should be initiated. Insecticides are commonly used for the control of CLM on young trees. Nicotine sulfate, IGRs, imidacloprid, alanycarb and pyrethroids are sprayed 4 to 5 times at 5to 10-day intervals during the flush developing period. Recently, CLM has become resistant to pyrethroids in some districts of Kyushu. To avoid the spread of insecticide resistance of CLM, an attempt was made to use the effective parasitoid, A. citricola, through introduction from Taiwan and Thailand to Japan. Discipline: Insect pest Additional key words: parasitoid, sex attractant

Age Estimation of Four Oceanic Squids, Ommastrephes bartramii, Dosidicus gigas, Sthenoteuthis oualaniensis, and Illex argentinus (Cephalopoda, Ommastrephidae) Based on Statolith Microstructure

Abstract: Statolith preparation and observation methods adopted in Japan were reviewed for 4 ommastrephid squids, Ommastrephes bartramii, Dosidicus gigas, Sthenoteuthis oualaniensis, and Illex argentinus. Relationships between mantle length and age were exponenitial at the early life stages and almost linear at the subadult and adult stages. Discipline: Fisheries Additional key words: growth JARQ 34, 7580 (2000)

Robotization of agricultural vehicles (Part 2). Description of the tilling robot.

Abstract: We have developed a tilling robot that can recognize its own position and heading, while performing unmanned tilling at almost the same work rate as manual work. The tilling robot is composed of navigation systems for positioning and heading, a robotized vehicle, a controller, and an operation software. A geomagnetic sensor (TMS) is utilized for the navigation system for heading. The operation software consists of teaching, path planning, vehicle controlling, self-diagnosis, and abnormality alarming sections. We found that the tilling robot can perform unmanned tilling operations over a whole field area of 50 a with almost the same efficiency and accuracy as manual work. Discipline: Agricultural machinery Additional key words: mobile robot, unmanned operation, operation software, tractor, navigation Development of till ing robot I) Tilling robo1 The BRAINJAM has accumulated data related to technology for robotization of agricultural vehicles from several trials since 1988 -·>. The Ministry of Agriculture, Forestry and Fisheries launched an agricultural machine development project in the fiscal year 1993. A 5-year plan for the development of a tilling robot ( 1993 to 1997) was implemented under this project. This development was performed jointly w ith KUBOTA Co., Japan Aviation Electronics Industries, Ltd., Hokkaido Univ. and BRAINJAM. The objective of the tilling robot is to develop a working vehicle that can recognize its own position and heading, while performing unmanned tilling, including headland treatment, at the same work rate as a manual operation. The target specifications are shown in Table I. The fields are limi ted to paddy fields and upland fields that cover an almost flat and rectangular area. In our study, the robot works with in sight of the operator, which enables the operator to stop the robot by remote control in case of emergency. 2) Target spec/fications for the navigation sys1em The performance required for the navigation system of ti lling robots or robot ized agricultural vehicles is outlined in Table I . This table specifies the concurrent provision of positional information and the vehicle heading informat ion. For position accuracy, we assume that the overlap width of the implement should be approx. I O cm. The tolerance was set for half of that value to avoid untreated areas. The heading accuracy was set so that the ovcrlar> w idth of the implement would be maintained i f the vehicle was operated autonomously, depending only on the heading information for a length of approx. 100 111 of the assumed field and taking into consideration the capacity o f the present heading sensor. Although the sampling interval for the posit ion data was set at I s or less, it is assumed that the transitory changes of position during this interval, as required, are complemented by dead reckoning, etc.

Diurnal and seasonal changes in CO2 concentration and flux in an Andisol and simulation based on changes in CO2 production rate and gas diffusivity.

Abstract: Changes in the concentrations and fluxes of CO2 were monitored to a depth of 100 cm in an Andisol, under both fallow and soybean crop for a period of one year. Gas flux was calculated by the diffusion equation. Diurnal concentrations at depths less than 40 cm followed a sinusoidal pattern similar to that of the soil temperature, with the highest value being recorded in the daytime. Heavy rainfall which closes air voids open to the atmosphere resulted in a higher CO2 concentration in the shallow soil layers. The subsequent decrease in the concentration in the shallow layers by the recovery of diffusion paths to the atmosphere was accompanied by an increase in concentrations in the deeper soil layers. CO2 concentration profile under soybean showed a peak at depths that increased gradually from 20 to 80 cm with the growth of the roots. Upward CO2 fluxes decreased with depth in both fields, and the fluxes in the soil profile were high in summer and low in winter. CO2 fluxes from the soil surface calculated by the diffusion equation and measured by the closed chamber method were fairly well correlated. Annual CO2 fluxes were 3,522 g m-2 under fallow and 4,975 g m-2 under soybean. The CO2 movement in soil was simulated by use of the diffusion first law combined with the mass conservation equation. This mechanistic model enabled to analyze phenomena occurring under field conditions, suggesting that soil aeration is controlled by gas diffusion. Discipline: Soils, fertilizers and plant nutrition Additional key words: carbon dioxide, gas diffusion

Variation in southern blight fungus in Japan detected by ITS-RFLP analysis.

Abstract: PCR-RELP analysis of the ITS region in the ribosomal RNA gene cluster revealed that Japanese isolates of the southern blight pathogen consisted of 5 groups. Groups 1, 2 and 3 corresponded to Sclerolium roljsii, whereas groups 4 and 5 were similar to S. delphinii, a related species of S. roljsii. Most of the isolates belonging to groups and 2 were detected in the central to southwestern regions of Japan, while groups 3, 4 and 5 were distributed in the central to northern regions, Although the ITS-RFLP groups also differed in the size of the sclerotial, the sclerotial size varied with the incubation temperature and became indistinguishable at high temperatures. These groups showed hyphal anastomosis with one another, indicating their con specificity. Discipline: Plant disease Additional keywords: Sclerotium rolfsii, Selerotium delphinii

Evaluation of Structural Characteristics of Naturally Ventilated Multi-Span Greenhouses Using Computer Simulation

Abstract: Natural ventilation system modifications were evaluated using a computational fluid dynamics (CFD) numerical model (code: Fluent Version 4.5). Wind speed and direction, side vent opening size and location, roof vent opening type, and number of spans were examined in terms of ventilation rates and airflow distribution. For the side vent located at 2.5 m above the floor with a west wind of 2.5 m/s, 59% of the incoming air through the side vent was predicted to move out through the first roof vent opening without reaching distant areas in the greenhouse, resulting in high inside air temperatures. The air mainly moved in through the side vent and fourth roof vent openings for an cast wind of 0.5 m/s while the third and fourth roof openings were the only predicted inlets of airflow for an east wind of 2.5 m/s. The hinged open roof multi-span greenhouses were predicted to have significantly higher natural ventilation rates than the double polyethylene-covered multi-span greenhouses for all the spans in the absence of side vent. Discipline: Agricultural facilities Additional key words: computational fluid dynamics While mechanical ventilation systems are still widely used throughout the industry presently, high energy costs associated with market-driven production methods have forced growers to consider alternative means of ventilating their greenhouses in order to remain competi tive. While natural ventilation systems can be very difficult to design properly, increased emphasis is being placed on such systems for greenhouses as they generally require less electrical energy, less equipment operation and maintenance, and arc much quieter than fan ventilation systems. tivc cooling from plants, and some forms of shading systems. Natural ventilation is achieved by air exchanges through multiple openings due to natural pressure variations inside and outside the greenhouse. Wind is the primary driving force making natural ventilat ion systems very difficult to design properly because of variations in the wind velocity and direction. The optimization of these systems for suitable climate contro l requires a thorough knowledge of the airflow rates and patterns in relation to weather conditions and greenhouse structural characterist ics>. A successful numerical model was assumed to be an ideal tool to analyze the complex phenomena of natura l airflow and help designers choose optimum designs. There was a particular interest in computat ional fluid dynamics (CFO) numerical techniques to analyze the air distribution in agricultural structures as well as air quali ty and thermal conditions>. A common goal of vent ilation system designs for greenhouses during hot summer weather is to keep the inside air temperature as close as possible to the ot1tside air temperature. For natural ventilation, this object ive is generally achieved by using high air exchange rates, evaporative cooling systems such as fogging, evaporaThe objective of th is study was to evaluate the consequences of various modifications of natural ventilation * Corresponding a11thor: fax +81298387609, e-mail ilcc@nkk.afTrc.go.jp Received 27 October 1999, accepted 2 March 2000.

Analysis of Relationship between Root Length Density and Water Uptake by Roots of Five Crops Using Minirhizotron in the Semi-Arid Tropics

Abstract: Experiments were carried out to analyse the root and water dynamics simultaneously using a minirhizotron on an Alfisol soil in the semi-arid tropics in 1993. Sorghum (CSH 5), pearl millet (ICMV 221), pigeonpea (ICP 1-6), groundnut (ICGS 11) and cowpea (EC 82-7) were used to describe the relationship between the root length density (RLD) and water uptake by roots per day (WU). During the periods from 37 to 46, from 51 to 59 and from 72 to 77 days after sowing, the average values of RLD of sorghum and pearl millet at the soil depth of 15-60 cm were consistently higher than those of pigeonpea, groundnut and cowpea, whereas the average values of WU of the cereals were not always higher than those of the grain legumes. Thus, there was no significant relationship between RLD and WU for the 5 crops due to the higher values of the specific root water uptake (SRWU) of grain legumes than those of cereals in each period. In this study, it was demonstrated that WU and SRWU as well as RLD for the 5 crops could be estimated by using the minirhizotron since dynamic values of the root length of the 5 crops and soil moisture content (SMC) in each soil layer could be quantified from datasets by frequent observations and with limited sampling errors. Therefore the minirhizotron was found to be a suitable tool for simultaneous monitoring of the root and water dynamics in soil layers except for the soil surface.

Diversity of rice varieties and cropping systems in Bangladesh deepwater areas.

Abstract: Sixty-eight indigenous rice cultivars collected in deep water areas in Bangladesh were examined in terms of heading behavior and allozyme variation. Seasonal ecotypes differed in the heading behavior for adaptation to their respective cropping seasons. Isozyme analysis revealed that cultivars grown in deepwater areas in Bangladesh consisted of a Japonica-like group and unclassified unique group in addition to a major Indeca group. Classification by isozyme variation was not neees sari! y consistent with the differentiation in to seasonal ecotypes. Cultivars collected in a restricted area in Khulna District consisting of various seasonal ecotypes showed a genetic similarity to each other, suggesting that geographical differentiation preceded seasonal differentiation. Based on a case study conducted in 2 villages in Khulna, it was pointed out that diverse landraces which are adapted to different local and seasonal conditions have evolved by interacting with traditional planting systems. Discipline: Genetic resources Additional key words: heading behavior, isozyme, varietal differentiation

Role of semiochemicals in prey-locating behavior of a generalist predatory stink bug, Eocanthecona furcellata (Wolff) (Heteroptera: Pentatomidae).

Abstract: Behavioral responses of a generalist predatory stink bug, Eocanthecona furcellata towards larvae of several lepidopteran species were observed in order to analyze the role of semiochemicals in cliciting a prey-locating behavior in this bug. Extracts of Spodoptera litura larvae elicited approaching behavior in E. furcellata. A hexane-eluted fraction from silica gel chromatography of the larval extracts was also attractive to the bugs. The hexane fraction contained n-tetradecane, n-pentadecane, n-haptadecane, n-heptacosane, n-nonacosane, n-hentriacontane and 2, 6, 10, 15, 19, 23-hexamethyl-2, 6, 10, 14, 18, 22-tetracosahexaene (squalene). Synthetic n-pentadecane was attractive to the bugs. On the other hand, a 15%-ether-in-hexane-eluted fraction from silica gel chromatography of the solvent extracts of S. litura stimulated bugs to display a proboscis-protruding behavior. (E) -3, 7, 11, 15Teramethyl-2-hexadecen-1-ol [(E)-phytol] was identified in this fraction, and synthetic (E)-phytol showed the same effect on the bugs as the fraction. (E)-phytol content of larvae increased depending on the amount of chlorophyll in the diets. These results suggest that (E)-phytol in larvae, which is derived from chlorophyll in the prey diet, acts as an important cue in the prey-locating behavior of the generalist predatory stink bug, E. furcellata. In conclusion, the 2 different chemicals act as “kairomones” in the prey location for the predatory stink bug, E. furcellata. Discipline: Insect pest Additional key words: n-pentadecane, (E)-phytol, attractant, proboscis-protruding inducer, chlorophyll, kairomone

Nitrogen Fixation Activity by Periphytic Blue-Green Algae in a Seagrass Bed on the Great Barrier Reef

Abstract: Acetylene reduction activity, an index of nitrogen fixation, by epiphytic and epibenthic algae and coral debris was measured in seagrass beds around Green Island, Australia. Epiphytic blue-green algae showed a high activity, ranging from 56.1 ± 31.9 to 729 ± 105 mmol (g chl a) -1 d-1 on a chlorophyll basis, or 3.9 μmol N2 m-2 d-1 to 16 mmol N2 m-2 d-1 on an areal basis. The activities on an areal basis were comparable to those reported in a Fijian seagrass bed, whereas activities on a chlorophyll basis were higher on Green Island than on Fiji. A relatively high activity was observed on the leeward side of the island, partly due to the high seagrass biomass and partly due to the high epiphyte biomass. This trend of high activity on the leeward side of the island suggested that the biomass and/or activity of nitrogen fixing blue-green algae could be affected by unknown mechanism (s) related to the island environment. Algae on (or in) coral debris, which were abundant around live corals, were able to reduce acetylene. Discipline: Fisheries / Environment Additional key words: acetylene reduction, stable isotope ratio JARQ 34, 6973 (2000)

Transformation of taro (Colocasia esculenta Schott) using particle bombardment.

Abstract: Transgenic taro (Colocasia esculenta Schott) Plants were obtained by high-velocity particle bombardment. The plasmid pREXHGUS, carrying the hygromycin resistance gene, was used as a selection marker. Highly regenerative taro callus was obtained from the apical meristem, maintained in liquid culture. The callus was chopped into small fragments with a forceps, then transformed and selected on LS medium containing BA, NAA and hygromycin. Since the transformed calli obtained showed vigorous growth on LS-BN medium with 20 mg/L hygromycin, this concentration was considered to be suitable for the selection of transgenic taro. The transform ants were confirmed by amplification of the GUS gene, and Southern hybridization. The expression of the foreign gene was demonstrated by the GUS activity. Discipline: Pl ant breeding Additional key words: callus, hygromycin resistance gene, GUS gene

Improvement of cell culture conditions for rice.

Abstract: Cell culture techniques are necessary for the use of biotechnology including the production of transgenic rice plants. However, there are significant differences in vitro culture responses among rice varieties. These differences limit the application of biotechnology to genetic improvement of rice. In this study, it was demonstrated that nitrite reductase activity is one of the physiological factors correlated with the differences among rice varieties in cell culture. It was indicated that the modification of the culture medium was effective in overcoming the differences in cell culture: the calluses of some Indica and Japonica type varieties showed a poor growth or did not grow under the initial conditions, whereas the calluses of all the varieties tested showed good growth when the nitrogen source, carbon source and medium pH were modified. As a result, in this stud, the culture conditions applicable to a wider range of varieties, including Indica type, Javanica type and Indica-Japonica crossed varieties as well as J aponica type were identified. Discipline: Biotechnology Additional keywords: Oryza sativa, abscisic acid, amino acid, genotypic difference, nitrogen metabolism

An Immunohistochemical and Ultrastructural Study of Thymic Lymphoma in a Steer

Abstract: A thymic lymphoma was found in a 14-month-old Holstein steer. Use of antisera applicable to paraffin-embedded sections showed that the tumor cells were of T-cell lineage. Although the cells were characterized histologically by the presence of irregular nuclei, electron microscopic examination disclosed that they were cleaved. Although nuclear convolution and cleavage are important in the sub typing of some human lymphomas, these characteristics may not be related to the immunophenotype of the tumor cells bovine lymphomas. Introduction Discipline: Animal health Additional key words: bovine, T -cell Nuclear convolution which is a cytological marker for lnunan T-cell malignancies may be present in human thymic lymphomas2•>. Valli et a1.> divided canine, feline and bovine lymphoid tumors into cleaved and non-cleaved types, but complex indentations of tumor cell nuclei producing serpentine profiles were recognized ultrastructurally in a canine cutaneous lymphoma>. In addition, the presence of nuclei showing a convoluted or clovcrlcaf-l ikc conformation was verified by electron microscopy in canine9> and swine·8> thymic lymphomas. There is no convincing evidence that nuclear convolution occurs in bovine lymphomas including the thymic form. Here we describe a case of bovine thymic lymphoma, with emphasis placed on the ultrastructmal observa tion of the shape of the nucleus in the tumor cells. Materials and methods Tissues were fixed in I 0% neutral buffered forma lin and processed according to standard methods for paraffin embedding. Sections were stained with hematoxylin and eosin (I IE). Additionally, selected sections were stained by the avidin-biotin-peroxidase complex immunoperoxidasc technique (ABC). The following monoclonal antibodies were used: ant i-human CD79a (HM57) (Dako, Denmark) and ant i-major histocompatibility complex class II (MHCII) (H42A) (VMRD, USA). Anti-human CD3 (Dako) was also uti lized. An immunoperoxidase staining kit (BioGenex Laboratories, USA) was used in the subsequent processes. For electron microscopy, small pieces from formalin-fixed tissues were post-fixed in I% osmium tetroxide, embedded in epoxy resin, stained with uranyl acetate and lead citrate, and examined by transmission e lectron microscopy (TEM).

Prospects and strategies for precision farming in Japan.

Abstract: Precision farming is bringing about a new revolution in agricultural farming systems with its high potential of reducing the environmental impact and increasing the productivity, based on the high efficiency of advanced technology. Variability management is the key approach in precision farming, using field maps and real-time sensing for temporal and spatial variation in soils, plant growth and yield, and other parameters related to cultivation. Site-specific field management can be implemented based on accurate information. Scale-free precision farming approaches are suitable for small-scale Japanese agriculture. Prospects and strategies for Japanese precision farming are introduced, followed by the results derived from investigations on soil mapping and the use of soil sens ors. Discipline: Agricultural engineering Additional key words: small-sized farm, variability soil map, soil sensor

Varietal Differences in Palatability of Orchardgrass (Dactylis glomerata L.) and Breeding for Palatability and Quality

Abstract: Palatability of 14 varieties of orchardgrass (Dactylis glomerata L.) was evaluated with Holstein heifers by using a trough cafeteria method for 4 years. Highly significant differences in the palatability of varieties were recognized throughout the growing seasons in each year. Multiple regression analysis was carried out in 15 cafeteria trials to identify the variables which could predict the palatability of varieties. Among 41 available variables, the best combinations of 2 variables were identified in each growing season. For all the seasons, the concentration of Ca, the concentration of P, and flexibility of leaf and stem were considered to be the best positive predictors for the palatability. In contrast, ADF and 3 kinds of diseases (Rhynchosporium scald, rust and total leaf diseases) were considered to be the best negative predictors for the palatability. Lude, a French variety, exhibited superior characteristics in quality compared with other varieties, namely, high palatability, resistance to rust and total leaf diseases, high flexibility of leaf and stem and the highest concentration of Ca among the tested varieties. Intake of fresh materials in 2 varieties, Lude and Akimidori was compared by using Holstein heifers, It was observed that the estimated increase of dry matter intake (DMI, g/kgBW0.75) of Lude over Akimidori was 3.49 g at the same DMD level, High palatability in Lude might have a positive effect on the DMI level and could increase it more than expected from the DMD level. A model for the improvement of both palatability and quality which includes digestibility and mineral-balances was proposed as a part of the forage breeding program in Japan. Discipline: Grassland / Plant breeding Additional key words: cafeteria trial, calcium disease, flexibility, Holstein heifer, intake

Earthquake Damage to Fill Dams in Japan

Abstract: Earthquakes have caused considerable damage to fill-type dams. Research into earthquake damage has contributed to the study of earthquake resistance of dams. However damage to fill dams occurred almost only in the case of small-scale earth dams, especially in the few cases of serious damage. This report describes the damage and performance of earth dams and fill dams more than 15 m high during carthquakes, based on literature data as well as field surveys. The results indicated that even stronger earthquakes than the designed earthquake intensity did not cause heavy damage to large well-constructed modern dams. The above analysis of the performance of fill dams during earthquakes shows that large-scale dams are earthquake-proof. Discipline: Agricultural engineering Additional key words: earth dam JARQ 34, 39-48 (2000)

Potential Risk of Transmission and Spread of Foot-and-Mouth Disease in Kagoshima Prefecture, Japan

Abstract: In March 1997, outbreaks of foot-and-mouth disease (FMD) affected pigs in Taiwan. To assess the potential risk of transmission and spread ofFMD, a survey on normal movement pattern in livestock farms was carried out in Kagoshima Prefecture, Japan. In a total of 20 farms (9 for pig farrow-to-finish operations, 6 beef cattle farms and 5 dairy cattle farms) participating in the survey, all the movements to or off the farms (e,g. animals, materials and people/ number of contacts and destination) were recorded daily over a period of one week using a questionnaire. The movements were classified into 4 grades: risk 4 (very high) to risk 1 (low), respectively, assigned to the types of contacts. The movements off the farm were more frequent than those to the farm in each livestock farm. In particular the movements off the pig farms were cone entrated on animal shipping to slaughterhouse with grade risk 4. Mean distance of shipping also extended over a radius of more than 20 km of the control zone for FMD emergency in Japan. Should an outbreak of FMD be detected in a pig farm, FMDV might, therefore, have already spread prior to the diagnosis of the disease over the FMD control zone. Discipline: Animal health Additional key words: epidemiology, risk analysis

Mechanized production system for orchards on sloping land in Japan.

Abstract: In Japan, most of the farm operations in orchards on sloping land in the past had been carried out manually, since no suitable machinery was available. However presently, the problem of aging farmers and shortage of young successors, especially for citrus orchards on steep hillsides must be solved. Therefore, a mechanized production system (J:...1PS) for orchards on sloping land was developed involving the construction of farm paths and the use of machines behind which the operator walks, such as airblast sprayer, raised bed transporter, and fertilizer spreader. The benefits of J:...1PS were confirmed by comparison with a conventional production system (CPS) in an actual farmer's orchard at Yoshida town, Ehim e prefecture, which is one of the 1 ea ding ci trus-produ cti on districts in Japan. The use of this system enabled to reduce the total working hours by 35% as well as improve the working conditions without yield decrease and decline of the quality offruits. Discipline: Agricultural machinery Additional key words: Farm path, pest control, transportation, fertilizer application

Development of an eye camera for measuring eyelid and eyeball movements in domestic animals.

Abstract: The analysis of the resting behavior of domestic animals must include the analysis of eyelid and eyeball movements and bodily motion. We developed an apparatus for measuring the movement of eyelids and eyeballs of domestic animals. The apparatus consists of a charge-coupled device (CCD) camera placed in the eyelid region of a head mask, and an infrared light-emitting diode as light source. Two types of apparatus have been developed: one, using a wire system and the other, using a measurable telemetry system in an unrestricted state. The weight of the device with the wire system was about 50 g and that with the telemetry system was about 880 g. The operating time of the telem etry system was 24 h or more when nickel-hydrogen was used in the power supply. By using the wire system in calf, the movements of the eyelid and eyeball could be divided into four categories: fully open eyelid movement, half-closed eyelid movement, fully closed eyelid movement and eyeball movement. The results showed that the time of half-closed eyelids and fully closed eyelids while the animal was lying down was longest from midnight to 7: 00 a.m. and eyelids were half-closed or fully closed even during rumination. In the horse, the telemetry system device could be used continuously without discomfort for 24 h. Comparison of the eyelid movement and cortex brain waves, showed that the power spectrum of the cerebra! cortex brain waves in an animal 1 ying down with ah alf-open eyelid mainly consisted of 6 waves while when the animal was standing with a fully open eyelid, a. waves al so appeared. Discipline: Animal industry Additional keywords: brain waves, behavior analysis