Effect of Nitrogen Level on Two Tomato Cultivars Under Plastic House Conditions

Two tomato cultivars Lycopersicon esculentum Mill. Marmande and Pearson, were tested under three nitrogen levels (10,20, and 30 gm N/m2) in plastic house at Dirab Experimental Station, King Saud University. Data of growth showed that Pearson plants gave the highest values for plant height, leaf area, fresh weight, and dry matter content. Nitrogen applications increased dry matter up to the highest level (30 gm N/m2), but plant height, leaf area, and fresh weight were not affected. A significant response of each cultivar to N applications was observed for fresh weight and dry matter content. Regarding yield and yield components, Marmande cultivar produced the highest number of fruits/plant and more total yield. Nitrogen treatments did not affect total yield or any of its compo-nents. Marmande reflected no response of total yield to N, suggesting that 10 gm N/m2 was suffi-cient for the cultivar. The number of fruits and total yield of pearson plants increased with N appli-cation up to 20 gm N/m2, but the fruit weight decreased, suggesting that 20 gm N/m2 favored Pear-son production