Tomato and salinity

The effects of salinity on tomato plant growth and fruit production, the cultural techniques which can be applied to alleviate the deleterious effects of salt, and the possibilities of breeding salt-tolerant tomatoes are reviewed. Salinity reduces tomato seed germination and lengthens the time needed for germination to such an extent that the establishment of a competitive crop by direct seeding would be difficult in soils where the electrical conductivity (EC) of a saturated extract was equal to or above 8 dS mÿ1. Priming seeds primed with 1 M NaCl for 36 h seems advisable to establish a crop by direct sowing in saline soils, and seedling conditioning, either by exposure to moderately saline water exposure or by withholding watering until seedlings wilt for 20–24 h, can be recommended for crops that are to be established by transplanting. Yields are reduced when plants are grown with a nutrient solution of 2.5 dS mÿ1 or higher and above 3.0 dS mÿ1 an increase of 1 dS mÿ1 results in a yield reduction of about 9–10%. At low ECs, yield reduction is caused mainly by reduction in the average fruit weight, whilst the declining number of fruits explains the main portion of yield reduction at high ECs. Since the smaller the fruit, the less important the reduction in fruit weight caused by salt, small size tomatoes are recommended to be grown a