Keywords: Tomato, heat tolerant, summer season

Fourteen tomato genotypes were evaluated for their plant morphological characters, yield potential and fruit characters during the summer of 2000 at the Institute of Agriculture and Animal Science, Rampur, Chitwan, Nepal. RCB design was adopted with four replications. Genotypes varied largely in their morphological characters, such as number of primary braches from 9.59 to 71, plant height from 131.3 cm to 49.6 cm, number of leaves per plant from 748.5 to 198.2, number of flower trusses per plant from 103.10 to 34.94, and number of flowers per truss from 5.38 to 3.33. Wide variations were also observed in yield potential of the genotypes ranging in fruit set rate from 79.33% to 16.43%, number of marketable fruits per plant from 133.10 to 4.26, yield per plant from 1.378 kg to 0.334 kg and yield/ha from 40.530 tons to 9.829 tons. The fruit size differed in weight from 93.55 gm to 7.30 gm, fruit volume from 95.50 ml to 6.90 ml and fruit diameter from 5.61 cm to 2.22 cm. The fruit quality characters were also observed with significant variation ranging total soluble solids from 4.77° Brix to 3.34° Brix, pH of fruit juice from 4.33 to 3.96, thickness of outer wall of pericarp from 4.95 mm to 1.74 mm, and number of locules from 5.91 to 2.05. Genotypes Bari-5 (40.53 mt/ha), Bari-4 (39.83 mt/ha), CLN 1621 L (31.33 mt/ha) and Lapsigede (29.84 mt/ha) were found significantly high yielder revealing their high fruit set ability during hot summer condition of Chitwan. These genotypes also possess good fruit quality characters acceptable for curry relishing and processing. Genotypes with medium yield, namely CLN 2026 D (23.47 mt/ha) and CLN 2026 C (22.42 mt/ha) were found suitable for all types of consumption purposes, especially more suitable for fresh table purpose. Hence, these six genotypes should be further tested for two more seasons, and if proved good can be recommended for cultivation by farmers in Chitwan and Chitwan like conditions.