The effects of salinity on dry matter partitioning and fruit growth in tomatoes grown in nutrient film culture

Abstract

Tomato plants were grown from three successive sowings in nutrient film culture at different salinities. When the electrical conductivity of the nutrient solution was in the range of 2,4 and 6 mS neither the total plant dry weight nor the proportional distribution of dry matter into fruit (52%), vegetative shoot (44%) and roots (4%) was affected. However, when the conductivity was 10 mS total plant dry weight was reduced by 19% of that at 2 mS, although the proportional partitioning of dry matter into various organs was still unaffected. The proportion of total plant weight in fruit was only reduced slightly at 17 mS. The effects of salinity on fruit growth were investigated for seven weeks beginning seven days after anthesis. The increase in fruit fresh weight was markedly reduced by high solution conductivities (12 and 17 mS) and the fresh weight of mature fruit grown at 17 mS was 40% less than that of fruit grown at 2 mS. In contrast, the dry matter accumulation by individual fruit was not affected by salinity and, therefore, the percentage dry matter of the fruit was markedly increased by high salinity’. The proportion of dry matter as sugars or starch in the young fruit was decreased or increased, respectively, by high salinity.