Abstract: In this study, a source-sink growth unit, which composed of a fruit truss, three pieces of leaves just below this truss and the corresponding stem, was adopted for understanding the dry matter production of tomato crop in three different planting time: over-winter cultivation planted in Oct. 26 (OW); early-spring cultivation in Feb. 17 (ES) and spring-summer cultivation in Mar. 29 (SS), respectively. The results showed that within a source-sink growth unit, fruit dry matter distribution was between 42.6% and 98.6%. Fruit dry matter distribution decreased by 6% with the increasing of the fruit truss number (the lowest fruit truss is the first truss), supposing the seven fruit trusses simultaneously existed in the same plant. When ripe fruits were picked, the distribution of immature fruit dry matter was increased due to the increase of the fruit sink strength. Dry matter production in different cultivation varied a lot due to the obviously different greenhouse climate. The ratio of fruit dry matter to shoot dry production were 72%、62% and 59% for OW, ES and SS cultivation, respectively. Fruit dry matter distribution of SS cultivation was lower than the other two treatments due to the lower rate of fruit-set, when facing high temperature in summer season. The accumulated dry weight in first 100 days after planting was only 1/3 of that in the later growing 100 days in OW cultivation, which was related to low temperature and low light intensity.

Key words: Tomato, Solar greenhouse, Crops, Dry matter production, Dry matter distribution, Source-sink growth unit