Abstract
The purpose of this research is to clarify the effect of shade on the growth, fruit yield and dry matter partitioning to plant organs of single truss tomatoes, Licopersicon esculentum Mill. cv. “House Momotaro.” Plants were grown in a greenhouse under three shade levels (0, 50 and 70%) from May to June (Exp. 1) and under four shade levels (0, 25, 45 and 80%) from September to November (Exp. 2) . In both experiments, plant dry weight decreased as shade level became more intense. Also, fruit yield and dry plant organ weight at the harvesting period reduced as the shade level increased. However, there were no marked differences in the proportion of organ dry matter distribution among different shade levels with the exception of 80% shade plants, which had no fruit. Further, the heavier shade increased the ratio of dry matter partition to leaf for the earlier period from 10 to 40 days of shading in Exp.
2. On the other hand, in the plants grown under 0, 25 and 45% shade levels, the ratio of dry matter partition to fruit for the latter period of Exp. 2 were higher than those of the plants for the earlier period. The plants under 45% shade partitioned the highest proportion of dry matter to fruit among the four shade levels during the harvesting period in Exp. 2.
