The pathogenicity of 46 fungal species isolated from bananas for which agricultural chemicals such as pesticides are not used during the production and postharvest operations (hereafter referred to as “non-chemical bananas”) imported from the Philippines was examined. Thirty-eight species were pathogenic while 8 species were non-pathogenic to non-chemical banana fruits. The lesions caused by the pathogenic fungi to non-chemical bananas consisted of circular to oval blemishes chocolate brown to black in color on the pericarp. These lesions were similar although the rate of lesion enlargement was different for each causal fungus. Ten fungal species that were pathogenic to wounded fruits were likewise capable of producing lesions on unwounded fruits. Among these fungi, Lasiodiplodia theobromae, Colletotrichum gloeosporioides, Phoma exigua, Colletotrichum musae, Penicillium waksmanii, Penicillium citrinum, and Aspergillus flavus were the most pathogenic based on the lesion diameter and infection rate of non-chemical bananas. Moreover, Thielaviopsis paradoxa, Phomopsis sp., Fusarium verticillioides, and F. oxysporum were serious pathogens affecting only wounded fruits. On the other hand, Verticillium tricorpus, Trichoderma saturnisporum and the unidentified species belonging to Monilia, Cylindrocarpon, Spiromyces, Oedocephalum, Oidiodendron, and Aureobasidium were non-pathogenic to non-chemical bananas.

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The effect of the combined application of solutions of CPPU and GA₃ on fruit growth was investigated in ‘Irwin’ mango. Two applications of 10ppm or 20ppmCPPU plus 100ppm GA₃ to whole panicles from the full bloom stage caused abnormal fruit growth and no fruit set could be obtained. When the same treatments were applied from the end of the flowering time, fruit growth was not appreciably affected and the TSS contents of the fruits decreased. Spraying of 10ppm CPPU plus 100ppm GA₃ to panicles twice and 4 times from the end of the physiological fruit drop stage promoted fruit growth. The effect was more pronounced with 4 applications than with 2 applications. Total yield per tree increased because of the increase in the average weight of both seeded and seedless fruits and the number of harvested seedless fruits increased with 4 applications. The ratio of bigger-seeded fruits weighing of more than 400g was about 60% of that of the total number of harvested fruits with 4 applications, followed by nearly 45% with 2 applications and about 25% in the control. Spraying the solution 4 times increased the ratio of seedless fruits weighing more than 200g but did not produce any seedless fruits weighing more than 400g. More frequent applications of the solution to panicles tended to delay the fruit maturity as well as to decrease the sugar content in ripened fruits. These results indicate that the combined application of 10ppm CPPU plus 100ppm GA₃ from the early stage of fruit growth, which promoted fruit enlargement, has a potential to increase the commercial value of ‘Irwin’ mango fruits, but at the same time the treatment may decrease the quality of ripened fruit.

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In the Moshi district, a major area for coffee production in Tanzania, coffee is grown under a traditional agroforestry system, referred to as kihamba system, together with many varieties of annual crops, root crops, fodder, banana and useful tree species in the same field. Since the introduction of coffee trees to the district in the mid-1880s, Cu fungicides (mainly Bordeaux mixture) had been applied for disease control as an economically suitable measure. Although there had been some concern about possible Cu contamination of soil, no studies have been conducted on this aspect in Tanzania. The objectives of the current study were to determine the present levels of copper in soils and to evaluate the potential risk for the maintenance of the traditional agroforestry system.
The natural background level of total Cu ranged between 37.8 and 97.8 mg kg^-1 (58.7 mg kg^-1 on the average, n = 4) . On the other hand, the total Cu level in soils under the kihamba system with coffee ranged between 153.1 and 451.6 mg kg^-1 (316.1 mg kg^-1 on the average, n=15) . The highest value of 2, 308.1 mg kg^-1 was recorded in the soil under single stands of coffee. Comparison of the total Cu levels among soils differing in their cultivation history showed that the Cu levels tended to increase with the duration of the period of coffee cultivation. The levels of Cu in the soils were compared, in reference to the threshold value of 125 mg kg^-1 of 0.1 M HC1-Cu that is the critical level of Cu pollution in cultivated paddy soils in Japan. In two soils, the values were higher, 177.4 and 330.6 mg kg^-1, and in some others, the levels ranged between 78.7 and 97.0 mg kg^-1 The results obtained suggested that there was an increasing risk of Cu accumulation that might adversely affect the coexisting crops grown for the subsistence and nutrition of the local people although the current Cu content in most soils has not yet reached a critical level under the kihamba system.

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Maize growth, nutrient uptake, spore density of indigenous arbuscular mycorrhizal fungi (AMF), and soil fertility were compared in two different maize fields located on the northern side of the Uluguru Mountains in Tanzania, and the function of AMF under the indigenous farming system was estimated. Maize grew well in the field where a higher AMF density and AM infection rate were observed. Although the contents of soil nutrients were similar in both fields, a lager phosphorus uptake was observed under higher infection rates of AMF Using the soil from this field, maize was grown after fumigation and/or inoculation of one of the indigenous AM fungal species to investigate the effects on the growth and nutrient uptake. Phosphorus uptake was promoted by the AM infection and plant growth was enhanced, without differences in the nitrogen content. The indigenous farming system in which indigenous microorganisms such as AMF were preserved, was found to contribute to the sustainability or improvement of agricultural production.

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Uses and cultivation of taro species were investigated in the Red River Delta and the mountainous region of northern Vietnam, to analyze the present situation and to compare the two ecological areas. Morphological characteristics, ploidy, and ribosomal DNA (rDNA) variation were examined for the taro plants collected. Colocasia esculenta var. esculenta, C. esculenta var, aquatilis, C. gigantea, Xanthosoma sagittifolium, X violaceum, Alocasia macrorrhiza, and A, odora were detected in the surveys. The uses and habitats of C. esculenta var. aquatilis were linked to the agroecosystems of the delta. The plant was frequently found around canals and farmers' ponds in the delta, and its petioles and stolons were harvested for human consumption and pig fodder. Its importance as pig fodder seemed to have declined gradually, due to the recent social and economic changes. Colocasia esculenta var. esculenta was grown mainly as a cash crop in the delta. On the other hand, it was grown for local consumption in the shifting cultivation system at a mountainous site. Genetically close cultivars of var. esculenta were found within each ecological area, but not between the areas, based on the Restriction Fragment Length Polymorphism (RFLP) analysis of rDNA. This distribution in northern Vietnam may reflect the influence of differences in the dispersal in Asia. Xanthosoma spp. were found at all the sites, and there was a similarity in their uses and cultivation. The accessions of Xanthosoma spp. were genetically uniform. Colocasia gigantea was not very common, but was widely distributed and used as a vegetable.

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The effect of chilling injury (CI) on the cell wall metabolism was investigated in stored‘Rongrien’rambutans (Nephelium lappaceum L.) . CI was observed only in the skin of the fruits stored at 8°C. Cellulose accounted for approximately 80% of the composition of the skin cell wall and for about 60% of that of the pulp. Skin firmness decreased with the number of days in storage (DIS) at 8°C and was lower than at 13°C. Cellulose concentration in the skin at 8°C was higher than that at 13°C. The inconsistent relationship between the skin firmness and cellulose concentration implies that if the cellulose concentration remained at a certain minimum level, it may not influence the firmness. This concentration may exceed 27 g⋅kg^-1 FW. In contrast, the concentrations of sodium hexametaphosphate-soluble pectic substances (HMP) in the skin at 8°C were lower than those at 13°C and decreased with DIS. These results suggest that HMP concentrations may influence the skin firmness of fruits where CI was observed. Cellulose concentration in the pulp was about 3 g⋅kg^-1 FW at both 8°C and 13°C, and was high compared with that of other components. Although the HMP concentrations in the pulp were lower at 8°C than at 13°C, no significant differences in firmness were observed. Cellulose concentration may strongly influence pulp firmness, in contrast, to the skin.

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Amorphophallus paeoniifolius (Dennsteadt) Nicolson (elephant foot yam) plants were collected from different regions in Java to analyze the diversity of morphological and nutritional characteristics among accessions. Principal component analysis of nine morphological characteristics showed that 74% of total variations could be explained by the first four components. Scatter diagrams of the first and second components showed that 32 accessions could be classified into five groups, A to E. A comparison of growth habitats among these groups revealed the fact that most of the plants in groups A, B, and E were collected from lowland areas while most of the plants in group C were sampled in upland regions. Plants in group D did not show any distinct characteristics in terms of growth habitat. Using cluster analysis, the 32 accessions were divided into three groups, I, II, and III. Cluster I consisted of groups B, D, E, and two of the nine accessions in group C. On the other hand, cluster II corresponded to group A, and cluster III corresponded to the remaining seven accessions in group C. Starch concentrations in the corms ranged from 36 to 114 mg g^-1 fresh matter, while the sucrose concentrations ranged from 0 to 2.3 mg g^-1 fresh matter. It is unlikely that the carbohydrate concentration was related to the classification based on morphological characteristics.

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Unprocessed coconut (Cocos nucifera L.) coir (CC) of tropical origin and carbonated rice husks (CRH) were used as substrates for tomato (Lycopersicon esculentum Mill.) production, and their characteristics as well tomato characteristics and productivity were investigated compared with the use of rock wool (RW) . There were no significant differences in the stem diameter, root dry matter (%), fruit set (%), weight of individual fruit, harvest index, contents of ascorbic acid, total soluble solids, fruit pH and leaf chlorophyll content. There were smaller fluctuations in the relative growth rate (RGR), net assimilation rate (NAR) and leaf area ratio (JAR) among the treatments. The results suggested that these substrates did not affect or exerted a negligible effect on the plant responses and that the productivity of tomatoes by the use of the above substrates was almost similar to that in the case of rock wool use. Based on the chemical characteristics of the substrates, crop performance, quality parameters, incidence of diseases and costbenefit analysis, CC was found to be best among the substrates for tomato hydroponics. CRH also showed suitable properties and performance for use as growing medium. Thus, CC and CRH substrates can be used successfully as amendment for container media for the production of potted crops especially in the tropical and subtropical areas.

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Agrobiodiversity needs to be conserved urgently because it faces rapid erosion. Bilateral and multilateral cooperation projects and programmes have been implemented for the effective and efficient management of agrobiodiversity. Although Japan has been active in this field, most of its programmes have dealt with infrastructure development and scientific research at public organizations.
The global trend of agrobiodiversity management activities and development cooperation has changed drastically in recent years from the conservation of materials for breeding or public organizations to integration of genetic resources management into rural development in developing countries. This focus is compatible with social and participatory development.
Historically, Germany and Japan have shared similar technical cooperation strategies. Both emphasized ex situ conservation and infrastructure development. However, this investigation reveals that Germany has already integrated the new framework of the global system consisting of such treaties as Convention of Biological Diversity (CBD) and Trade-Related Intellectual Property Rights (TRIPs) into its programmes. At the macro-level, the German Technical Cooperation Agency (Deutsche Gesellschaft fur Technische Zusammenarbeit, GTZ) extends its programmes in policy and legislation, and at the micro-level, it carries out projects for participatory conservation and rural development.
The research-oriented cooperation extended by JICA needs to be evaluated in light of the changes in the international trends of agrobiodiversity management. JICA should utilize the existing network of human resources involved in natural and socio-economic research in other projects for rural development and it should also extend its strong experience in capacity building of public sector organizations.

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High occurrence of shallow root distribution in soybean plants grown in the Yguazú district of Paraguay was observed in long term no-tillage fields where soil compacted layers that developed at a 5-15cm depth impeded soybean root elongation. For better root development of soybean plants, a field experiment was conducted at CETAPAR in 2000/01 to evaluate the effects of slit-sowing which is a method where by the soil compacted layers are slit by using a culter attached to a no-tillage seeder and seeds are down on the slit track simultaneously. Treatments consisted of 3 slit depths of 5 (S-5), 10 (S-10) and 15cm (S-15) . Tap root length of the soybean plants was 8.9, 11.6 and 14.9cm for the S-5, S-10 and 5-15 treatments, respectively, at the primary leaf expanding stage. Soil hardness index at 10 days after sowing was 10.5-11.2, 8.7-9.7 and 1.1-2.3kg/cm^-2 for S-5, S-10 and S-15, respectively. Thus, the deeper slits significantly decreased the soil hardness resulting in the improvement of the elongation of the tap roots. Abnormal roots at the flowering stage occurred at rates of 82, 58 and 22% for S-5, S-10 and S-15, respectively. It is concluded that the deeper tap root elongation at the early stage due to deeper slits in sowing decreased the occurrence of abnormal root distribution. Soybean yields were 3.2, 3.5 and 3.8t/ha for S-5, 5-10 and S-15, respectively. This study indicated that slit-sowing in long term no-tillage fields of “Terra Roxa”, fine-textured red soil, was effective in increasing in soybean yields with improved root distribution.

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Germplasm collection of the tribe Triticeae was conducted at 88 sites in Sind, Baluchistan and the North West Frontier Province of Pakistan from May to June, 2001. Common wheat spikes were collected in 81 fields and eight seed samples were collected, in addition to wild relatives as follows: Aegilops cylindrica at three sites, Ae. squarrosa at nine sites and Ae. triuncialis at two sites. Collection of Ae. cylindrica was newly recorded in this region of Pakistan. At 31 sites, barley spikes and three barley seed samples were collected. Cultivated rye spikes were collected at only one site and triticale spikes at four sites. Eremopyrum bonaepartis, Hordeum murinum and Secale segetale were also collected. The germplasm collected in Pakistan is preserved at both the Plant Genetic Resources Institute, National Agricultural Research Center, Islamabad, Pakistan and the Graduate School of Agriculture, Kyoto Prefectural University, Kyoto, Japan.

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