MORPHO-PHYSIOLOGY AND YIELD OF TOMATO (Solanum lycopersicum L.) VARIETIES AFFECTED BY DIFFERENT LEVELS OF LIGHT INTENSITY

Abstract

Light stress is a limiting factor for crop production, especially in agroforestry system.

A pot experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka- 1207, during the months of October 2019 to mid-April 2020 in a completely randomized design (CRD) to determine the effect of low light on morpho-physiology and yield of tomato. Three tomato varieties viz. BARI Tomato-2, BARI Tomato-15, BARI Tomato-16 were exposed to four light intensities including 100% (S 0 , control), 75% (S 1 ) , 50%

(S 2 ) , and 25% (S 3 ) to evaluate their performances. Light stress (mainly S 2 and S 3 ) substantially hampered the plant growth, development as well as yield. Low light stress primarily reduced the photosynthetic performance of plants which contributes in reduction of plant height, number of primary branches, and leaves of all tomato plants. Moreover, low light intensity negatively affected the fresh and dry weight of tomato. It also decreased the number of fruits, fruit length, fruit diameter, and individual fruit weight in all varieties. As a result, plant wise tomato production was hampered seriously with low yield. In comparison with control, S 1 condition decreased tomato yield per plant by 22.5, 16.9 and 15.3% in BARI Tomato-2, BARI Tomato-15 and BARI Tomato-16, respectively. Under S 2

condition, tomato yield per plant decreased by 38.7, 37.4, and 32.7% in BARI Tomato-2, BARI Tomato-15 and BARI Tomato-16, respectively, in contrast to control. Lastly, S 3 condition decreased tomato yield per plant by 73.1, 67.0 and 62.1% in BARI Tomato-2, BARI Tomato-15, and BARI Tomato-16, respectively, compared with control. From this result, it was clear that BARI Tomato-16 was more tolerant to low light stress than BARI Tomato-2 and BARI Tomato-15.