Tomato growth and dry matter partitioning as a function of the irrigation water quality

Abstract

In this study, the growth and dry matter partitioning of processing tomato cv IPA 6 were evaluated under irrigation with waters of different electrical conductivities (ECw) and sodium proportions in a completely randomized 5x2 factorial design. Seedlings were transplanted to rhizotrons and irrigated daily, being the dry masses of stem, branches, inflorescences and fruits determined at the end of the crop season. The soil was removed from the rhizotrons at 15 cm depth intervals, washed and sieved to determine the dry mass of roots at each soil layer. Shoot dry mass was reduced by 6.9% for each unit increase of salinity. Root dry mass decreased in the 30-45 cm layer and increased in the 0-15 cm layer due to the  accumulation of salts in the deeper layer promoted by the leaching. Salinity and sodium proportions did not affect root growth, which increased after transplanting, reaching its maximum of 50 cm day-1 during the period between 30 and 40 days after transplanting. Dry matter partitioning was practically unaffected by salinity and sodium proportions.