Stimulation of embryo germination and growth, and multiple shoot induction from sago (Metroxylon sp.) embryo in vitro were examined. Activated charcoal was not essential but stimulated embryo germination and growth. In the initial stage of culture, germination and growth of sago embryos in the dark seemed to be better than in the light. However, when the culture was prolonged no significant difference was observed between the dark and light conditions. No stimulation effect was observed when up to 25mg/l thiamine· HCl and up to 510mg of additional monosodium phosphate were used. The currently modified Murashige & Skoog's medium gave the best results among the three media examined. Inositol at 150mg/l most stimulated embryo germination and growth among the concentrations examined with 150μM benzyl aminopurine. Factorial combination of benzyl aminopurine and either of indole butyric acid, naphthalene acetic acid or 2, 4-dichlorophenoxy acetic acid was examined to identify the conditions suitable for embryo germination and growth, and induction of multiple shoots from embryo cultures. Benzyl aminopurine or naphthalene acetic acid at 150μM stimulated embryo germination and growth. Gibberelic acid up to 1000 ppm did not stimulate seedling growth. Within 3 to 4 months the majority of the plantlets were able to grow and reached a 20-25cm length under the present conditions. Multiple shoots or mini suckers were occasionally observed from embryo cultures in combinations of plant growth regulators at high concentrations. Adventitious shoots were also formed from embryo cultures in combinations of plant growth regulators at high concentrations. Vertical halves of shoots, which were excised from in vitro grown seedlings could grow. Based on these results, three possible techniques for the micropropagation of sago plant were suggested. When in vitro-grown plantlets were transplanted in potted soil, within a month all the plantlets were dead. However, since new roots developed from the plantlets which lived for a long period of time it is assumed that acclimation may be successful. Sago plantlets may not be able to adapt to the climatic conditions in Japan.

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Characteristics of the growth and development of Guava fruit cultivated in plastic house were studied in relation to various pinching and defoliation treatments.
1. The growth curve of guava fruit assumed a double sigmoidal shape and the fruit matured at 20-22 weeks after anthesis.
2. Only fructose and glucose were detected in the fruit, unlike sucrose. Large amounts of sugars and vitamin C accumulated during the latter period of fruit development. The contents of some of the chemical components of mature fruit were 2.5-3.0 mg/l00 ml for fructose, 2.0-2.5 mg/l00 ml for glucose and 150-250 mg/100g FW for vitamin C.
3. Fruit weight and the content of some of the chemical components of fruit increased by the pinching treatment when four leaves remained at the upper part of the fruit position on the branch. On the other hand, pinching at the fruit position and defoliation of all leaves at the lower part of the fruit position on the branch decreased the fruit weight and the content of some of the chemical components of fruit.
The results obtained suggest that the leaves around the fruit mainly contribute to fruit growth and the accumulation of chemical components. Therefore, the pinching treatment in which some leaves remained at the upper part of the fruit position enabled to produce Guava fruits with a higher quality.

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Among many diseases and insect pests observed in a Plau-Noi plantation in rainy season, Amyna punctum and root rot cause heavy damage for the Plau-Noi trees.
1. Amyna punctum (FABRlclus)
A large number of larvae of Amyna punctum appeared in the Plau-Noi trees which were older than three years in the rainy season from April to October in 1988. A small number of the larvae appeared in the trees which were younger than two years in the dry season from November to March in the same year. Carbaryl, 1-naphthyl methylcarbamate, killed the larvae of Amyna punctum in the shortest or most effectively among the insecticides used in this experiment.
2. Plau-Noi root rot
Leaves of the diseased Plau-Noi plants become thin and withered at the beginning stage of the diesease development. At the later stage, the leaves turn brown and fall off and the plant's growth stops with dried branches. Finally, the whole plant dies within a few weeks.
The occurrence of Plau-Noi root rot was related to rainfall frequency of harvesting, plowing and mulching, and soil nutrients. Plau-Noi root rot can be controlled by the following procedure: plowing field well, application of enough amount of fertilizers with 60 g dazomet, 3, 5-dimethyl-1, 3, 5-thiadiazine-2-thione, per square meter to soil, mulching field by cover crops, and harvesting once or twice a year.

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The present study was undertaken to investigate the translocation in sugarcane plants of ¹⁴C-glyphosate administered as ripener through foliar application and to analyse the effect of glyphosate on seed set germination and sprouting of ratoons from stool after harvest of the first crop. After one week of treatment, approximately 70% of the applied radiocarbon remained at the treated site of plants. However, the ¹⁴C-labelled material was also detected in all parts of the plants. The translocation of ¹⁴C-glyphosate applied on the leaf blade surface was very rapid. The translocation of glyphosate to the apical meristem and spindle leaves was more effective when glyphosate was applied on the leaf blade near the spindle than far below the leaf. In the treated portion of sugarcane plants, the level of radioactivity was higher in the leaf blades than in the leaf sheaths, and in the nodes of stalks than in the internodes. After eight weeks of treatment, the amount of translocated glyphosate, except for the treated leaf blades, reached values of 4.29 ppm, 0.20-0.39 ppm, 0.18-0.5 ppm and 0.19-0.27 ppm for the meristem, nodes, elongated lateral buds and ratoons, respectively. However, the level of radioactivity in the internodes was the lowest as compared with other parts. On the other hand, the difference in the amount of glyphosate translocated into each part of the plant depended on the duration of the treatment with glyphosate.

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In order to obtain a better understanding of the mechanisms of environmental adaptation in buffaloes, an experiment was conducted at the Agricultural and Forestry Research Center, University of Tsukuba. The effects of seasonal air temperature on the physiological responses and characteristics of blood in buffalo-cows were compared with those of Holstein cows during a period of one year.
The rectal temperature, respiration rate and heart rate of buffaloes were lower than those of Holsteins during the experiment. Buffaloes showed significantly lower erythrocyte counts and a higher haemoglobin concentration than Holsteins. Since the haematocrit values were similar in both species, it is likely that buffaloes have larger erythrocytes than Holsteins. Furthermore, buffaloes showed significantly higher contents of serum glucose, total protein, calcium, creatinine and a higher alkaline phosphatase activity than Holsteins. Blood viscosity and haematocrit values in buffaloes significantly increased along with the decrease of seasonal air temperatures, whereas no marked changes were observed in Holsteins.

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‘Rome Beauty’apple can be grown without pollinizer at high region in east Java. This apple cultivation is different from that in temperate zone where pollinizer is needed for the fruit set. Self-compatibility is considered to be high in such tropical region. In this study the possibility that‘Rome Beauty’apple can produce the seed by self-pollonation was studied.
Most fruits had seeds and the number of seeds became more in the orchards with pollinizer than those without one. Under non-pollinizer condition, many seeded fruits were produced although the number of seed contained in the fruit were fewer, suggesting that self-fertilization is conducted. Hand pollination of self-pollen to the stigma could produce the seed. This result confirms that seed can be formed owing to the self-pollination. Seeds formation of‘Rome Beauty’without pollinizer seems to be resulted from self-pollination in the tropical high land. Fruits with fewer seeds under self-pollination had nearly the same size as those with more seeds under pollinizer. There was little relationship between fruit diameter and fruit size in the orchard without pollinizer, although some positive relationship was found in the orchard with pollinizer. Seeds number does not seem to relate to the fruit growth.
This study indicates that the capabilities of fruit set and fruit growth without pollinizer are ascribed to the seed formation by self-pollination in the cultivation of‘Rome Beauty’apple at tropical high land in east Java.

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Land and agriculture in Sub-Sahara Africa are in serious crisis. Sustainable upland farmings are not yet established and lowland agriculture has been neglected long time in most parts of the tropical Africa. In addition to this, population explosion, deforestation, and drought accelerate the crisis. The origin of these African crisis, however, may date back to the long history of slave trade (because of destruction of African society) and the ages of colonization (because of destruction of agro-environment) . Therefore it will not be easy to recover these crises.
Although African rice (O. glaberrima) was domesticated thousands of years ago in some parts of West Africa, the Asian type of rice agriculture, “SUIDENNOGYOU” in Japanese, or “SAWAH” in Malayo-Indonesian, which means a leveled and bunded rice field, was not practiced. In contrast, rice is grown on a naturally sloping phreatic and flooding land.
The author described the strategy to regenerate society, agriculture and environment by wider scale introduction of Sawah based farming in lowland areas. Of the lowland ecologies of tropical Africa, the small inland valley swamps (IVS) have the best socio-economic and natural conditions to introduce African adoptive version of Sawah based rice farming with local farmers' participaiton. Each IVS is small in size, 10-100 ha. However total potential area for Sawah develpment may reach to 20-30 million ha. More than million farmers are growing rice in IVS in addition to grow various crops in upland in a watershed. A possible tactics for Sawah develpement in the IVS was proposed.

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