ABSTRACT
Two sowing dates (26 Sept. and 16 Oct.) were evaluated for yield and some morphological and quality factors of two hybrid tomato cultivars ('E 338' and ‘GC 774’) under plastic tunnel conditions in Guilan province, Iran. The early sowing had a significant positive effect (p = 0.01) on the yield and the number of fruits of both cultivars. The early sowing had also a significant effect (p = 0.05 and p = 0.01) on the plant height until development of the first inflorescence in ‘GC 774’ and on the distance between two inflorescences in ‘E 338’ (p = 0.01). Sowing date and genotype had no effect on the number of flowers in the first inflorescence and on the amount of soluble solids in tomatoes. The amount of organic acids in the fruits differed significantly (p = 0.05) in the early sowing only by ‘E 338’ cultivar. Vitamin C concentration was significantly different for different sowing date (p = 0.01), but were similar between the two cultivars.