In survey of paddy rice culm length, the longest culm is usually measured from the ground surface to the panicle neck node in a given number of rice plant hills sampled from sequential rows or from randomly selected test locations. A new method for estimating paddy rice culm and internode lengths from a single plant hill was devised in the course of yield assessment using Matsushima's method, which involves hills sampled five lines parallel to a diagonal one in a paddy field. A rice plant hill group with average number of panicles per hill was selected for yield assessment. Then a single plant hill to measure culm and internode lengths was selected from the either hill group having the average number of panicles per hill ± 1 panicle. The longest culm length of the population in the experimental plot was estimated with constant precision using the longest culm length or the average culm length of the measured hill. Therefore, this method provides a valid index comparable to conventionally measured longest culm length. The average culm length is particularly convenient for comparison among experiment plots regardless of different growth types N or N-1, i.e., difference in the pattern of internode elongation. In this assessment method, internodes of 2mm or longer were measured in 1 mm unit in all culms in a measured plant hill to calculate average internode lengths. Regardless of differences in years, cultivars and irrespective of classification by growth types, the population distribution of the average culm length exhibited normality. The respective internode lengths also showed a normal population distribution.

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To clear the effect of seed formation on polyphenol contents and antioxidant activity of eggplant fruit, total polyphenol, chlorogenic acid, anthocyanin and antioxidant activity of eggplant fruited by artificial pollination or hormone treatment were analyzed. It became clear that the effects of seed formation on these qualities differ by maturity of fruit and cultivars. In eggplant cultivars used in this study, the increase in chlorogenic acid and total polyphenol content and the rise of the antioxidant activity were observed in the unripe fruit of 'Minden Wase' in which seeds were not formed by the hormone treatment. Furthermore, improvement of the coloring grade accompanied with the increase in anthocyanin content was expected by hormone treatment in unripe fruit of Chikuyo'.

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Furrow is the place for manuring practice in tea field and is also used for managing pathway. In old times, even human ground contact pressure was intended to be decreased using straw mulch because the soil under the furrow has the role of manuring practice. For the mechanization of tea cultivation, the managing technology has to be developed and the influences of ground contact pressure on soil hardness were studied using soil pressure guage and artificial soil layer. The physical properties of furrow soil and tea plant growth and yields were measured changing travelling units, and travelling times in tea cultivating field. The tea yield and the plant growth with the crawler type machine showed not less than those of traditional cultivation method and around the same results were obtained at light wheel machine. In the case of heavy wheel machine, the yield and the plant growth were worse. Additional soil management was not necessary with the ground contact pressure in this study.

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