UPTAKE AND DISTRIBUTION OFNUTRIENTS IN RELATION TO TOMATO FRUIT QUALITY

A number of fruit quality problems of tomato, such as blotchy ripening and blossom-end rot, are caused by local deficiencies of K and Ca respectively. In this review, the effects of the concentration of K and Ca on uptake will be related to plant growth and fruit disorders. K and Ca uptake are closely related to water uptake, which is affected by light intensity, humidity and salinity. The uptake of these nutrients is also affected by plant age, fruit load, interactions with other nutrients in the feed and cultivar type. The difference in the distribution of K and Ca between plant organs isrelated to the mode of transport within the plant; K moves in both xylem and phloem whereas Ca moves only in the xylem. Consequently, there is a differential rate of accumulation of K andCa in the same fruit. The distribution of these nutrients is affected by light and air temperature, humidity and salinity. The cause of local deficiencies of K and Ca in the fruit are also discussed.