Fluctuation of ambient day‐night temperature influences morphological traits, floral characters, fruit yield and quality of summer tomato genotypes grown in hydroponics

ABSTRACT Tomato plants have, within certain limits, the ability to integrate temperature. In Bangladesh, tomatoes are typically cultivated during the winter season because the temperature during this period is optimal for their growth. But, there are some heat‐tolerant varieties, which can grow in summer. This study aimed to assess the effect of ambient day and night temperature fluctuation on floral characters, fruit yield and quality of different hybrid summer tomatoes. Three planting times were evaluated by exposing plants at flowering stage to average day/night temperatures of 28.1 ± 0.4/24.3 ± 0.3°C in March (early summer), 32.4 ± 0.2/28.5 ± 0.3°C in July (mid‐summer), and 30.1 ± 0.3/26.5 ± 0.2°C in October (late summer). Four tomato varieties— Beautiful , BARI Summer Tomato‐8, Rain Seed , and Lalbahadur —were tested. Results showed higher numbers of clusters, flower buds, flowers, and fruits in early and late summer plantings. Fruit yield, total soluble solids, bioactive compound content, and antioxidant capacity were also superior in these periods. BARI Summer Tomato‐8 and Lalbahadur achieved the highest yields (1,191 g/plant and 1,226 g/plant, respectively), significantly outperforming Beautiful (457 g/plant) and Rain Seed (710 g/plant). Quality traits followed a similar trend. Thus, BARI Summer Tomato‐8 and Lalbahadur are recommended for early and late summer cultivation to achieve higher yield and quality.