Effect of salt stress on dry matter production and nitrogen uptake by tomatoes

Dry matter yield and nitrogen (total and 15N) uptake of tomato plants (Lvcopersicum esculentum Mill., cv. Columbia) subjected to saline stress by NaCl were studied in a greenhouse. The treatments consisted of low (control), medium (4 bars), and high (8 bars) salinity. The saline treatments were prepared by adding NaCl to culture solutions. The plants were 80 days old at the start of the 15N treatments and each was in a pot containing 1.8 kg of quartz sand. The 15N was provided to plants by adding K15N03 to the pots and the 15N treatment period continued for 30 days. The plants were harvested at each 5-day interval during the 15N treatment period. Dry matter production and nitrogen (total and 15N) uptake were significantly lower for the saline treatments as compared with.