In fiscal year 2002, the production of nori (Porphyra sp.) markedly decreased to 60 % of the normal annual Nori yield at Kagawa prefectural coast, eastern Bisan-Seto. Moreover, the areas where the bad harvest was observed were confined to the northern part and the southwestern part of Shodo Island, and the annual Nori yield at these areas was about 30 % of that in the average year. Matsuoka et al. (2005) studied the horizontal distributions of salinity and nutrients, and they suggested that discoloration was mainly due to the small rainfall, and small nutrient load from the Yoshii River caused bad harvest in these areas. However, it was still unknown that how much influence the nutrient load from Yoshii River will have on these nori culture grounds. In the present study, inorder to investgate the origination of the nori discoloration, we calculated the trajectories of nutrient particles from the mouth of Yoshii River to the nori culture grounds using the multi-level numerical model. As the results, it was found that the trajectories of nutrient were affected by west wind velocity. It was supposed that bad nori harvest in fiscal year 2002 may due to little rain in the autumn. In addition, the nutrient supply to bad nori harvest area from the Yoshii River flowed from Okayama Prefecture was important for nori culture.

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A suitable application of the concentrated deep seawater for the high quality tomato production was examined by analyzing phloem transport to fruits. Tomato plants (Lycopersicon esculentum Mill.) were grown in the NFT system, where the concentrated deep seawater was applied to the nutrient solution at the stage of rapid fruit growth for the short-term (only two weeks) salt stress treatment. A heat-ring method was newly applied to the tomato pedicel to evaluate phloem fluxes of sap and soluble solids and concentrations of soluble solids in the phloem sap, and effect of the short-term application of the concentrated deep seawater was analyzed with special reference to osmoregulation in the phloem transport to tomato fruits. The phloem sap flux into the fruit was decreased by the short-term salt stress, but the soluble solids flux through phloem was significantly enhanced. The concentration of soluble solids in the phloem sap was remarkably raised from the start of the salt stress treatment, which was kept at the higher levels even after the removal of the salt stress. Concentrations of K⁺, Na⁺ and Mg²⁺ in the phloem sap were also raised by the application of the concentrated deep seawater. From these quantitative analyses of the phloem transport to tomato fruits, it was verified that the short-term application of the concentrated deep seawater at the stage of rapid fruit growth can induce the osmoregulation in the phloem transport to fruits and produce the high quality tomatoes enriched with sugar and minerals.

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This study investigated the effect of various types of water on the culture of embryos excised from rice seed. The rate of embryonic growth was highest in rainwater, showing a value of 64% 3 weeks after transplanting. Elongation of the auricle over 4 months was remarkable under rainwater conditions. Average leaf formation rates in purified water, rainwater and filtration rainwater were 4, 4 and 8, respectively. These findings suggest that slightly treated water affects rice plant embryo growth. Further, these data suggest that rainwater can be used for rice plant hydroponics.

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