Effects of the shade of foliage on the coloration of tomatoes for processing were investigated using c. v. Chico grownnin the experimental farm of Shimane University, Matsue under the nonstake system.
1) Intact fruits were selected and classified into seven groups from No.1 to No.7 plot on the basis of light intensity measured around each fruit. Mean light intesity of each plot as expressed by % of that of non shaded with foliage was as follows ; No.1 97.20, No.2 93.69, No.3 91.86, No.4 88.46, No.5 83.30, No.6 66.91, and No.7 34.78. The fruits of No.1 plot were almost directly exposed to the sun and fruits of No.7 plot could not seen over foliage due to overlapping of leaves.
2) Mean friut temperature was highest in No.1 plot and lowest in No.7 plot. The difference of the highest temperature in a day between the two plots was about 10℃. As to the lowest temperature, however, reciprocal relationship was found, but there was not such a notable difference between them.
3) Judging from Hunter a/b and Lb/a yalues, fruit color was superior in No.5, 6 and 7 plots, inferior in No.1 plot.
In conclusion, in order to get the favorable color, tomato fruits should be kept shaded with foliage receiving the sun less than 84% of open fruits in the environmental condition of this district.