Showing papers in "Jarq-japan Agricultural Research Quarterly in 1982"

Classification of Forest Soils in Japan

Abstract: Basis of forest soil classification in Japan was established by Dr . M. Ohmasa. In the study of beech forest soils in the Tohoku region, he classified them into 13 unit-types on the basis of morphological characteristics of soil profiles, and compiled them into 3 groups: Podzolic soils (6 types) , Brown forest soils (6 types), and Ground water soils (1 type) 0>. The basic principle of this classification was laid on morphological characteristics reflecting different moisture conditions mainly caused by microtopography of mountains. Accordingly, this classification offers a good indicator for physical and chemical properties as well as productivity of mountain soils, so that it is quite suitable for the soil grouping in such complicatedly dissected mountains as in Japan. In two forest soil survey projects, i.e. Soil Survey of National Forests started in 1947, and subsequent Soil Survey of Private Forests started in 1954, the Ohmasa's unit-types, to which Red soils, Black soils, etc. were added, were employed as the mapping units. At present, up to 85% of the national forests and 50% of the private forests are shown by the largescale soil maps, which are used effectively as the basic material for planning forest management such as determining suitability of sites for forestation, soil conservation, etc. In the course of these forest soil surveys, researches on forest soils were carried out in addition to survey works. Major research achievements obtained in relation to genesis and classification are as follows: The Red soils in Japan were found to be palaeosols formed in Pleistocene interglacial epoch2.a>. Among the Black soils, there are ones which have accumulated organic matter under immersed conditions, and become Black soil after drains>. Wet Podzolic soils have Iron-type and Humustype0>. Among the Brown forest soils, there are sub groups which show strong reddish or yellowish color7l. After the return of Okinawa and Ogasawara, soils of subtropical forests have come to be a new research subject, and it was made clear that Yellow soils dominant in these islands are formations under recent bioclimatic condition, and Red soils there are palaeosols as the case in the mainland4 l. Based on the results of survey and research conducted for more than 20 years, the forest soil staffs of the Forestry and Forest Products Research Institute have improved classification system, and published a new onet> (shown in Table 1) , which will be briefly described below.

The First Outbreak of Aujeszky's Disease in Swine in Japan

Abstract: Aujeszky's disease is caused by Suid herpesvirus 1. Since Aujeszky first reported the disease in Hungary in 19021 >, the distribution of the disease is now world-wide3,Gl. There has been a marked increase in the number of recorded cases in most affected countries, with rapid escalation to epidemic proportions in Holland, France, Belgium and the United States2>. Recently, the occurrence of the disease has been reported in several regions of Southeast Asia, Taiwan, Malaysia, Singapore, Thailand and continental China, however, there had been no occurrence of the disease among any animal populations in J apan. In February, 1981, an outbreak of Aujeszky's disease occurred for the first time in a pig farm in Japan.

Differentiation and Development of Tiller Buds in Rice Plants

Abstract: Development of tillers plays an important role for getting high yields of rice by increasing number of panicles per plant. The tiller develops from an axillary bud which differentiated on an axil of a leaf of rice plants. Number of tillers per plant depends on the differentiation of axillary buds (referred to as tiller buds hereafter) at leaf axils and the succeeding development of the tiller buds. It was shown by Katayama6l that the tillers develop synchronously with the development of the main stem, in other words, a leaf of a tiller develops synchronously with the development of a definite leaf of the main stem and those of other tillers. The present author carried out a series of experiments for the purpose of finding general rules involved in the processes of differentiation and development of tiller buds, and of knowing the effects of environmental conditions and some cultural practices such as transplanting and so on2,s,4,Ml . The results will be presented in this paper.

Theory of the growth of silkworm larvae and its application

Abstract: In the past, when the cause for unstable cocoon production was not known, the silkworm rearing technique was that centered on foods, with less relationship to growth of silkworm. However, after cytoplasmic polyhedrosis and infectious flacherie were discovered in 1952 and 1960, respectively, and method of controlling flacherie, the greatest cause of unstable cocoon production, was established in 19571962, the silkworm rearing technique has undergone a great change from the food-centered system of rearing technique to the new system based on the growth of silkworm used as an index, resulting in a marked progress in labor-saving. Needless to say, the growth expresses a composite result of various physiological activities of organisms, and is the basis of matter production and hence agricultural production . Growth is the accumulation of the matter, as a result of balance between assimilation and dissimilation, and in which complicated physiological phenomena are involved. Recent remarkable progress in silkworm physiology, especially nutrition physiology by the use of artificial diets, and insect hormone studies, has gradually clarified factors pertaining to the growth . However, physiological knowledges so far obtained have succeeded in clarifying only fragmental aspects of growth, by analysis of growth mechanism, but are not sufficient to make prediction how much growth can be attained with given conditions. In other words, there are difficulties, still now, in directly linking physiological facts to agricultural production. An immediate need for agricultural scientists is not individual physiological phenomena but rules governing matter accumulation.

Production of Antifungal Substances in Mulberry

Abstract: Silkworm rearing with mulberry shoots is widely popularized in Japan as a labor-saving technique. However, it is known that this technique often induces lowering of diseasetolerance of shoots or causes severe outbreak of shoot-killing diseases as the cut surface permits the entrance of diseases. In view of such a background, the authors have carried out a study on disease-resistance mechanism of mulberry. As a result it was found out that an antifungal substance, i.e. prohibition exists endogenously in the epidermal tissue of malberry shoots, and cortex and xylem tissues also produce antifungal substances, phytoalexins (PA), in response to the infection of pathogenic fungi, and that these antifungal substances are involved in the diseaseresistance. Chemical structure of these substances was determined by the cooperation of Dr. M. Takasugi et al. of the Faculty of Science, Hokkaido University.

Ecology of Grassland Weeds in Japan

Abstract: It is difficult to eradicate weeds in grasslands mechanically. Furthermore, the use of herbicides is undesirable because of their influence on livestock and of their high costs. Consequently, it is important to elucidate the ecology of weeds in grasslands and to control them by a proper management i.e. ecological control of weeds. The authors surveyed weeds of sown grasslands in Japan in order to make clear the ecological characteristics and methods of ecological control

Soybean mosaic virus isolated from soybeans in Thailand.

Abstract: Four isolates of soybean mosaic virus (SMV) from soybeans in Thailand were identified by host range, serology, transmission and electron microscopy. The host range of the four isolates differed in reactions in Chenopodium amaranticolor, C. quinoa, Tetragonia expansa and Phaseolus vulgaris 'Top Crop'. Isolates of SMV from Thailand could be classified into two serological groups which were different from a SMV isolate from Japan. The serological relationship did not appear to be correlated with the host reactions.

Studies on Gizzard Erosion-Inducing Substance in Fish Meal

Abstract: Since the study of J anssen6>, many reports on the gizzard erosion (GE) in broilers have appeared, and fish meal in the diet was considered to induce this lesion1,2,7 >. Among the constituents of fish meal, histamine, produced by the bacterial spoilage of fish, was suspected to be the causeS,4 ,11> . In the past few years, GE has also widely occurred in broilers and layers in Japans>, and its cause was investigated by many Japanese workers0,9 ,10. 12> . This paper reports on the toxicity of fish meal, especially the heat-treated, as well as chemically formed one, and on the attempt to purify the GE-inducing substance.

Immunodiffusion Studies in Bovine Leukosis

Abstract: Four forms of bovine lymphoid leukosis, that is, the adult, calf, thymic and skin forms have been recognized in the field from epidemiological, clinical and pathological points of view. The latter 3 types are found less frequently and accordingly, called the sporadic form. Their etiological agent still remains unknown. On the other hand, the adult form that occurs in herd aggregations and is called the enzootic fol'm is the most common and frequently seen among cattle in the world. Bovine leukemia virus (BL V) has generally been accepted as the causative agent of the adult type10, 11>. The virus spreads primarily by horizontal transmission°,22 >, propagates in the host animal, elicits the formation of antibodies and results in the onset of clinical lymphosarcoma or persistent lymphocytosis in a relatively small percentage of infected animals7,8>. As cattle once infected with BLV show persistent infection for life and become the source of viral contamination to healthy cattle, specific antibodies in animals have been examined by serological reactions for the diagnosis of BLV infection and for the control of bovine leukosis. It has been demonstrated that most of the animal positive for serological tests retain BLV in their lymphocyteso,21>. Many serological methods have been developed so far such as agar gel immunodiffusion test, complement fixation test, immunofluorescence, radioimmunoassay, syncytia in-

Energy Requirement for Pregnant Rats

Abstract: The goal of this study is to determine the minimum requirements of energy and protein in pregnant swine. Although there has been an increase in the amount of research undertaken with sows in recent years, there is still a serious shortage of experimental evidence on the nutritional needs of pregnant animals. Firstly, there is the difficulty that many of the important measures of reproductive efficiency are very variable. For example, a herd of 100 sows maintained under identical feeding regimes will include sows producing litters of from 2 to 20 pigs at birth varying in birth weight from 0.9 to 1.8 kg. Secondly, there is the problem of defining satisfactory criteria for the performance of pregnant animals. Thirdly, nutrient requirements for maintenance during pregnancy are not clear. Fourthly, efficiencies of utilization of dietary energy and protein by fetuses and placentas are also not elucidated. Lastly, the pregnant animals have an ability that protects the offspring against protein and energy deficiency of the diets by drawing on her own reserves to allow fetal survival. As mentioned above, there is the problem that what kinds of the index for determining nutrient requirements during pregnancy should be used for judging enough or deficiency of nutrients. This is a serious obstacle to elucidate nutrient requirements for pregnant animals. This study has been done to lay the foundation for determining the minimum nutrient requirements during pregnancy using rats prior to the experiments with pregnant swine. Nutrient requirements for maintenance during pregnancy5•6l

Soybean threshers in Japan and development of a new thresher

Abstract: : At present, soybeans are grown widely in Japan, from Hokkaido to Kagoshima, on about 150,000 ha of land. Mechanical ha1·vesting system and soybean reapers used in Japan were already reported in JARQ 14 (4)·1>. Reaping is usually practiced for soybean plants with fairly high moisture contents, such as 1825% for grains and pods, and 60-75% for stalks, in order to reduce shatter losses. The reaped plants are kept staying on the field fo1· natural drying, until moisture content of grains and pods becomes 14-17%, and that of stalks lower than 20%, and then threshed. In this report, the soybean threshers now being used in Japan, and the spiral-flow soybean thresher newly developed in the Institute of Agricultural Machinery will be presented. Soybean threshers on the market

Enzymatic Saccharification of Rice Hull Cellulose

Abstract: least, five billion tons of carbohydrates per year are provisionally estimated to be produced by land based plants alone. Of this biomass-I, about 25% is synthesized in farm fields and most of the remainder is synthesized in forests and grass lands. Furthermore, biomasses are recycled every year, and are, therefore, inexhaustible resources and are very abundant on the earth. But of these carbohydrates, only starch, accounting for a mere several percent of the total carbohydrates is presently being utilized by man directly as a food source. Cellulose, pentosan and hemicellulose (Biomass-Ill), which represent more than 60% of Biomass-I photosynthesized by solar energy are not being used as food at all. These still unutilized carbohydrates can be used as food, feed and chemical material if they can be converted into glucose and xylose through hydrolysis. In other words, we do have very large amounts of carbohydrate food resources that can be stored for long periods. In the face of the worldwide food and energy crisis due to the population explosion, we must positively proceed with research and development to make food and fuels etc. from unutilized carbohydrates (Biomass-Ill), products of synthesis by solar energy which abundantly exists on the earth. The past researches to convert cellulose into food have merely concerned theoretical possibility but this is likely to become of practical use as a result of the recent remarkable progress in cellulose chemistry and research on hydrolyzing enzyme. This article analyzes the present state of and problems in research on the enzyme saccharification of cellulose and is intended for reference on cellulose saccharification technology which will soon be developed.

Relations between the Vegetation and the Base-Status of Soils in Hokkaido, Japan

Abstract: Base-status is an important part of soil fertility and criteria of soil classification. According to the text by J. S. J enny4 >, the soil is a natural body and the result of the combined activity and reciprocal influence of soil forming factors such as parent material, plant and animal organisms, climate, age of land, and topography (Dokchaev) . Research on the base-status of soil and its correlation with soil-formers is significant for the development of agriculture in Hokkaido.

Blackgram Mottle Virus Occurring on Mungbean and Soybean in Thailand

Abstract: In 1979, the authors collected blackgram and mungbean plants showing mottling and mosaic symptoms from the southern part of Northern Thailand. The preliminary studies carried out by the authors indicated that the causal virus had icosahedral morphology and induced symptoms in certain hosts unlike those of the known viruses infecting blackgram or mungbean . After our preliminary studies, an isometric virus, blackgram mottle virus (BLMV), was reported from India.1> BLMV is transmissible by the bean leaf beetle (Cerotoma trifitrcata Forst.) and the Mexican bean beetle (Epilachna varivestis lVIuls.), and by mechanical inoculations in greenhouse.2> The beetle transmissibility and serological properties indicated that BLMV is a member of the beetle-transmitted virus groups. In the present report properties of the virus isolated from mungbean and soybean in Thailand indicating that it is beetle transmissible and serologically related to BLMV from India will be described. This work was conducted under the collaborative research project on \"Studies on rice and legumes virus disease in the tropics\" between t he Tropical Agriculture Research Center, J apan, and the Department of Agriculture, Ministry of Agriculture and Cooperatives, Thailand .

Quality Problems in the Mass-Rearing for the Melon Fly, Dacus cucurbitae Coquillett

Abstract: The mass-rearing of insects is necessary for the integrated pest management using augmentation of parasites or predaters and release of sterile or geneticalJy altered insects. In the earlier time, the primary problem in the mass-rearing was how to enhance the productivity of the rearing under low cost conditions6>. For this purpose, individuals having high fecundity were selected from the wild population in the course of colonization in laboratory and mass-rearing. However, this selection may also alter other characteristics of the insects. Boller2> pointed out the importance of behavioral aspects of massrearing of insects. Insects mass-reared should perform their typical behavior after released in the field. Some signs of deterioration in this typical behavior have been detected from the mass-reared insects. From the above point of view, quality problems have been concerned in the mass-rearing of insects3l. In the sterile insect technique (SIT) , the quality of sterile insects should be evaluated ultimately as sexual competitiveness under · the field conditions5>. Huettel4> defined two types of quality, those are, 'overall quality' and 'quality of specific traits'. The sexual competitiveness of sterile insects in the field conditions seems to correspond to 'overall quality'. When we consider the quality monitoring, 'quality of specific traits' should be measured. If quality of each specific trait for sterile insects released resemble that for the wild insects, we can expect the flies released have high 'overalJ quality', then they perform well their role in the field. If we find deterioration in a specific trait, the cause of such deterioration should be investigated and the method for mass-rearing should be improved. In the SIT program of the melon fly, Dacus cucurbitae Coquillett, on Kume Island, Okinawa, Japan, the wild melon flies were collected and colonized in 1972. The flies had been reared in the laboratory with an artificial conditions for 13 generations, and then massreared in the mass rearing facility in Yaeyama Branch of Okinawa Prefectural Agricultural Experiment Station, Ishigaki, Okinawa, Japan, for about 44 generations till November, 1979 (old strain). The rearing conditions were described by Nakamori and Kakinohana7>. From 1978 to 1979, a new strain was colonized in the mass-rearing facility, and was replaced for the old strain10l. From the stand point of quality problems, experiments were conducted for comparing several traits among mass-reared strains (old and new) and wild ones. In this report, the results of these experiments will be reviewed. In the following sections, 'wild strain' is adult flies collected from field in Okinawa or Ishigaki Islands as larvae and reared in the laboratory conditions for 03 generations with pumpkin fruit, a natural diet, for larvae, and sugar, protein hydrolysate and water for adult diets. The number of generations reared under mass-rearing conditions for mass-reared strains will be shown in each experiment.

Simulation Analysis of Dry-Matter Reproduction System in Winter Cereals

Abstract: Many researchers have carried out ecological studies on the photosynthetic function of cereals during various growing stages1,4,7l. In many cases, however, they might have faced with difficulty in compiling their experimental data into a definite relationship to grain yield productivity. For solving this problem, the present author and his coresearchers attempted to build a model for simulation of dry-matter growth in winter cerealso,ui. This study was conducted at the Second Division of Plant Physiology (Kitamoto, Saitama), National Institute of Agricultural Sciences, to which the author had belonged formerly. General structure of the model

Characteristics of Photosynthesis in Mulberry Leaves

Abstract: Cultivation of mulberry trees in Japan generally adopts the method by which mulberry trees are grown to stamps 30-40 cm in height above ground, enabling them to develop a number of shoots every year for harvesting. In March, before the sprouting, or in June, after the first harvesting, shoots elongated in the previous year are cut off at their basal portion to form mushroomshaped stamps. Sprouting of mulberry trees occurs in April, and leaf-fall from late November to early December. During that period, harvesting is made 2 to 3 times usually. As photosynthetic organs are harvested in mulberry trees, like pasture plants, the harvesting implies directly the damage or destruction of productive structure. In the past with plenty of labor available in rural areas, harvesting of lower leaves, leaving upper leaves with high photosynthetic activity unharvested, or harvesting by thinning 1/3 or 1/2 of a stamp was practiced with the consideration to alleviate adverse effects on roots as well as to reduce overgrowth conditions. However, at present, the method to harvest entire shoots including growing points that cause marked damage to productive structure is popularized. In a short term, the extent of the damage is in parallel to the yields. In view of that relationship, it is important to make clear photosynthetic characteristics of mulberry trees in order to establish a rational system of harvesting with regards to time, method and extent of harvesting.

Use of starter nitrogen for establishing tropical legume-grass pasture

Abstract: Tropical legumes are regarded to be an essential component for increasing pasture productivity throughout vast areas in the tropics and subtropics where N is an outstandingly deficient soil nu trient.;,s> . The beneficial role played by pasture legumes is to maintain or even enhance both quality and quantity of feed produced, and consequently to increase daily gain of grazing animals with minimum agricultural inputs. It is usually observed, however, that the tropical legumes are very slow to achieve their full dry matter production, biological N2-fixation, and possible transfer of the fixed N to associated grasses, and hence long time is required before the pastures enter into productive phaseio,H>. Quick pasture establishment which can increase pasture productivity in an establishing phase is the most important agricultural practice in areas of volcanic ash soil and steep slopes of southern Japan, since rainfall sometimes exceeds 100 mm per day during rainy or typhoon seasons, causing pasture erosions. Thus, application of starter N has been recommended in establishing tropical legume-grass mixtures, but published evidences to support this recommendations> are only few. In this paper, therefore, the author attempts to show the beneficial effects of starter N application observed in some agro-physiological experiments in which a tropical legume Desmodium intortum cv. Greenleaf and tropical grasses Setaria sphacelata cv. Kazungula and S. anceps cv. Nandi were used. Rates and methods of applying stater nitrogen

A New Analytical System for Feed Evaluation

Abstract: Proximate analysis of feed stuffs (Weende system) has been widely used in many countries. But, in this system, it has long been recognized that fraction of carbohydrates and lignin is imcomplete with respect t othe chemical characterization and nutritive availability. Numerous chemical and nutritional studies have been attempted1,10,12> to develop a new system in place of the proximate analysis. Recently, the study of detergent fiber0,10> has developed rapidly and its achivements have become a centre of attraction. However, more biological methods using various enzymes have been investigated by Abe et al.2•3•4> A new enzymatic system developed by the author will be presented in this paper. Method of enzymatic analysis

A New System of Environmental Control for Vegetable Growing in Greenhouses

Abstract: In recent years, a total area of greenhouses has increased rapidly in Japan, reaching 1,500 ha for glasshouses and 30,229 ha for plastic greenhouses in 1979. Of the area, 636 ha of glasshouses and 24,201 ha of plastic greenhouses are used for vegetable growing, accounting for 82.2% of the total area. Although the production of greenhouse vegetables constitutes only 11 % of the total vegetable production, the percentages for fruit vegetables are very high, i.e. 39 % for tomato, 35% for eggplant, 61 % for pimento, 54% for cucumber, 100% for netted melon, 88% for other melon, 74% for watermelon, and 87% for strawberry. Thus, thanks to the greenhouse vegetables, consumers are able to take fresh vegetables, especially fruit vegetables, even in the winter season.

Increase of Silage Corn (Zea mays L.) Productivity by Dense Planting

Abstract: Planting density is one of the major factors effecting productivity of corn plants. The density effect on production varied with climatic conditions, fertilizing levels, varieties, sowing times, etc. G,s,11,1 2,17> To determine what planting density can maximize the yield under a given environmental condition of each region is very important in corn cultivation. For instance, in the Corn Belt of the USA, a density of around 5,000 plants/IO a (are) has been recommended for grain production,6> while a little higher densities, 7,000 to 8,000 plants/IO a for silage production.2•7•15,ioi Thus, in the Corn Belt corn plants are grown at relatively low densities. Reasons why corn yield is reduced at higher densities are as follows3•'•5 •6 • 11• 12 • >: {l) growth delay, (2) reduced amount of substance distributed to ears, (3) appearance of barren plants caused by pollination trouble and others, (4) water deficiency and wilting due to increased transpiration with high LAI, and (5) lodging. i.VIany evidences 2, 3,18> proving that at least 10,000 plants/IO a is required for silage corn production have been reported in Europe where climatic condition is quite different from that of the Corn Belt in the USA. According to Bunting et aJ.3,4> in Britain, a density of 10,000 plants/IO a seems to be adequate for corn plants grown for silage in drier areas, but higher densities up to a maximum of 15,000 plants/IO a are justified in areas where soil water content is less limiting. Hokkaido, the northernmost island of Japan accounts for about 35% of the total corn area in Japan. Tanaka and Yamaguchi11> suggested that a highest dry matter production could be obtained by raising the density up to over 10,000 plants/IO a. At present, however, a considerablely low planting density, about 6,000 plants/IO a, is recommended as a standard for corn cultivation in Hokkaido. Silage corn production differs from grain production in that both stover and grain are similarly regarded as important yield components.1a,14> In this paper, increase of productivity of silage corn by dense planting is discussed in relation to climatic features in Hokkaido based on the data obtained from the experiments1012,1s> carried out for three years from 1977 to 1979, using two leading hybrid varieties grown around Sapporo of Hokkaido, Caldera 535 (early maturing) and Pioneer 3715 (late maturing).

Life Cycle of Cyperus Serotinus Rottb., A Perennial Weed, and Control Measures

Abstract: As a result of various changes in agricultural techniques and in agricultural situation which J1ave occurred in recent years in Japan, various perennial weeds have rapidly increased in paddy fields throughout the country. The infestation ·Of perennial weeds makes it difficult not only to develop labor-saving mechanized cultivation, but also to assure a better labor distribution to ·Other crops than rice. Therefore, it is an urgent task to develop effective control measures for the perennial weeds. C. serotinus, a perennial weed in paddy fields, is distributed widely in the whole country, and its control is a serious problem especially in areas -0f \"early season rice cultivation\" and of \"directsowing to dry soil.\"3•4•5•7•10> The author investigated physiological and ecological characteristics of this weed during its whole life process, together with agronomic and chemical methods of control, and designed an effective integrated control system. This study was carried out at Chiba Agricultural Experiment Station during a period from 1966 to 1976.