The model for estimating a developmental stage of rice plant using the DeVelopmental Index (DVI) was introduced by Hone et al. (1986). We conducted further research to clarify the function form of DeVelopmental Rate (DVR) to be applied to wide range of rice cultivating area in Japan. The objects of this study are to compare the functions of DVR obtained in Tsukuba and to apply this model to some local data sets.
Four rice cultivars were transplanted in Tsukuba three to four times a year in 1985 and 1986. The parameters of DVR functions were determined by the least squares method. Various DVR functions obtained in Tsukuba were applied to local data sets in Aomori and Miyazaki.
The standard errors of functions of both air temperature and a day length were smaller than that of air temperature alone. This tendency was significant for the cultivar, Mizuho. Under our experimental conditions, the DVR did not show a big difference between the linear functions and the nonlinear ones.
In local data sets, the longest and the shortest days from the transplanting to a certain stage were predicted. The modified model which has parameters determined from the Tsukuba data sets was more effective in prediction than the local model. Since the Tsukuba data included the one from several different cropping seasons, it must have worked efficiently to the excluded data.

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The effects have been investigated of closures and vessels on light intensities inside closed vessels. Four kinds of closures (aluminum foil cap (C_A), translucent polypropylene formed cap (C_P), silicon foam rubber plug (P_S) and transparent polycarbonate formed lid (L_P)) and three kinds of vessels (47ml glass flat bottom test tube, 132ml glass Erlenmeyer flask and 370ml polycarbonate box type vessel) were used. One straight fluorescent tube (cool white) was employed as a light source. Light intensities were measured using an illuminometer with a small photoreceptor. The measured illuminance [lx] was converted into the photon flux of 400-700nm wave lengths [μmol·m^-2·s^-1]. The results can be summarized as follows:
(1) The percentage of the photon flux reduction due to the closures to the photon flux on the shelf surface was 41% for C_A, 8% for C_P, and 49% for P_S in case the test tubes were used as a vessel, and was 17% for C_A and 24% for P_S in case the flasks were used as a vessel.
(2) The percentage of the photon flux reduction due to the test tubes including stainless wire frame stands, and the flasks, to the photon flux on the shelf surface was 36% and 7%, respectively.
(3) Mean photon flux inside the closed vessels was in the order:
C_A-flask (45)>P_S-flask(41)>L_P-box type vessel (38)
>C_P-test tube (33)>C_A-test tube (14)>P_S-test tube (9)
Values in the parentheses indicate the mean photon flux [μmol·m^-2·s^-1]. The mean photon flux on the shelf surface was 59 μmol·m^-2·s^-1.
(4) The photon flux inside each closed vessel was dependent on each position of the closed vessel on the culture shelf, and the distribution of the photon flux varied markedly with the closure-vessel combination.

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A nonparametric method is suggested to estimate development of plant. The concept of DVI (Developmental Index), which takes, for example, zero on sowing day and unity on heading day, has been used for the purpose. DVI is represented here as the summation of a nonparametric function of average temperature of each day. This nonparametric function can be calculated with an algorithm which is inspired by nonparametric smoothing.
A modification of this algorithm allows us to obtain a nonparametric function with inexpensive calculation. Further cross-validation not only makes this algorithm completely automatic but also let us know how valuable information this estimation is.
Some examples of heading of spring, wheat and flowering of apple show the efficiency of this procedure.

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Correlations between total rainfall variation in growing seasons and yields (kg/10a) of Peach and Japanese Pear at 3 typical production Prefectures were examined, and approximate quadratic equations were derived for Japanese Pear.
Rainfall variations in Baiu seasons (much rain in June and July) and midsummer (little rain in August), which were closely related to fruits culture distribution and management, were analysed using the Quintile Grouping of rainfall data. Ratios of rainfall/potential evapotranspiration were derived and compared by distribution maps with fruits culture regions in normal year, more rainy year (once in 5 years level) and less rainy year (same above).
From the prospect of climatic change in near future, the author appointed that warmer temperature and activiation or going north of Baiu Front might cause earlier outburst of pests and diseases and intensification of midsummer drought, which necessitated sufficient irrigation fascilities and water.

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An interpolation method was developed to estimate the 1km grid values of sunshine duration and solar radiation in Hiroshima Prefecture from the data observed at the AMeDAS stations distributed with a mean distance of about 21km. In the first step the influence of shading by the surroundings was removed from the average sunshine duration observed at the AMeDAS stations, and the duration without the influence of shading was estimated by the distance weighting interpolation in each grid. These values were converted to the values with the influence of shading by using the elevation data in the surrounding grids of National Land Numerical Information. Equation (6), which related sunshine duration to solar radiation, was derived to draw the solar radiation map. As an example of the application of our method, we drew the sunshine duration map for ripening period of rice plants and discussed their most suitable heading time taking into consideration the annual course of air temperature.

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