EFFECTS OF IRRIGATION WATER SALINITY ON TOMATO PRODUCTION UNDER PROTECTED ENVIRONMENT1

Abstract. The tomato cultivated in protected environment provides higher yields and best quality of the fruits. However the effects of a continuous cultivation with low water quality and an inappropriate fertigation management, together, can result in increased salinity with consequent reduction in production, since irrigation is the only source of water supply to plants in protected environment. For better crop management in these environments is important to know the response of tomato to different levels of salinity. Based on this, this study aimed to evaluate the total and marketable yield of tomatoes grown with different levels of salts in the irrigation water. The plants were transplanted into pots with 20 liters capacity, placed on a platform of 0.20 m high and 0.60 m spacing between plants and 1.00 m between rows. It was used a drip irrigation system. The experiment was carried out in a completely randomized design with 5 irrigation water salinity levels (S1 = 0.05; S2 = 1.5; 3.5 = S3 and S4 and S5 6.5 = 5.5 dS m^-1 at 25 ° C) and five replications. The total and marketable yield decreased with irrigation water salinity. The irrigation with 6.5 dS m^-1 resulted in production drop of 88.7% for total production and 92.5 % marketable production drop.