INTRODUCTION Tomato (Lycopersicon esculentum Mill.), under the family Solanaceae is one of the important, popular and nutritious vegetable crop grown in Bangladesh during rabi season (Mondal et al., 2011). It is cultivated in almost all home gardens and also in the field due to its adaptability to wide range of soil and climate (Ahmed, 1976; Chopra et al., 2017). It ranks next to potato and sweet potato in the world vegetable production and tops the list of canned vegetable (Choudhury, 1979). Tomato is highly nutritious as it contains 94.1% water, 23 calories energy, 1.90 g pro- tein, 1 g calcium, 7 mg magnesium, 1000 IU vitamin A, 31 mg vitamin C, 0.09 mg thiamin, 0.03 mg riboflavin, 0.8 mg niacin per 100 g edible portion (Rashid, 1983) in comparison to its requirement (Aditya et al., 1999; Chopra et al., 2017). The low yield of tomato in Bangladesh, however, is not an indication of low yielding ability of this crop, but of the fact that low yielding variety, poor crop management practices and lack of improved technologies. Tomato is cultivated generally in winter season. There is considerable interest in extending the cultivation of tomato over a longer period. In the dry season with high temperature, flower abortion occurs and fruits drop frequently, which causes very poor yield of tomato (Nahir and Ullah, 2012; Chopra et al., 2017). Howev- er, high temperature before and after the short winter season inhibits the flower and fruit development, use of plant growth regulators, viz. gibberellin and auxin has been reported to be very effective to overcome the problems of flower and fruit development in tomato (Adlakha and Velma, 1965; Groot et al., 1987). GA 3 , particularly, is known to pro- mote fruit development in pollinated ovaries that undergoes dormancy due to high temperature (Johnson and Liver- man, 1957 ). Fruit set in tomato can be increased by applying plant growth regulators to compensate the defi- ciency of natural growth substances required for its develop- ment (Singh and Choudhury, 1966). Therefore, it was ORIGINAL RESEARCH ARTICLE Interaction effect of seedling age and different doses of GA 3 on growth and yield of tomato (Lycopersicon esculentum Mill.) Rumpa Sarker 1* , Sasthi Pada Ray 2 , Juthika Paul 3 , Awfiqua Nusrat 4 and Sharmila Rani Mallick 5 1 Scientific Officer, Spices Research Sub-Centre, Bangladesh Agricultural Research Institute ,Faridpur -7800, BANGLADESH 2 Assistant Director, Bureau of Manpower, Employment and Training, Manikgonj -1800, BANGLADESH 3 Agricultural Extension Officer, Department of Agriculture Extension, Dhaka-1207, BANGLADESH 4 Lecturer, Agricultural College, Gazipur-1701, BANGLADESH 5 Scientific Officer, Regional Pulse Research Station, Bangladesh Agricultural Research Institute Madaripur-7900, BANGLADESH * Corresponding author’s E-mail: rumpakbds@gmail.com Archives of Agriculture and Environmental Science 2(4): 301-304 (2017) https://doi.org/10.26832/24566632.2017.020409 This content is available online at AESA Archives of Agriculture and Environmental Science Journal homepage: www.aesacademy.org e-ISSN: 2456-6632 ARTICLE HISTORY Received: 08 October 2017 Revised received: 07 November 2017 Accepted: 14 November 2017 Keywords GA 3 Growth and yield Interaction effect Seeding age Tomato ABSTRACT An experiment was conducted in the Horticultural Farm of Sher -e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka-1207 during the period from October 2010 to March 2011 to find out the effect of GA 3 and seedling age on the growth and yield of tomato. The experiment was laid out in randomized complete block design ( RCBD) with three replications. The experiment consisted of four concentration of GA 3 such as control G 0 = no GA 3 , G 1 = 75 ppm GA 3 , G 2 = 100 ppm GA 3 and G 3 =125 ppm GA 3 ; three different seedling ages such as S 1 = 20 days, S 2 = 25 days and S 3 = 30 days old seedling. All parameter varied significantly at different concentration of GA 3 in different DAT. The combined effect of G 3 S 3 (125 ppm GA 3 with 30 days old seedling) gave the maximum yield (90.28 t ha -1 ), on the other hand combined effect of G 0 S 1 (no GA 3 with 20 days old seedling) gave the minimum yield (59.83t ha -1 ). The maximum yield (2.79 kg) plant -1 was recorded from treatment combination of G 3 S 3 and the minimum yield (1.20 kg) was recorded from treatment combination G 0 S 1 . The maximum yield (32.47 kg) plot -1 was recorded from treatment combination G 3 S 3 and the minimum yield (21.52 kg) plot -1 was recorded from treatment combination G 0 S 1 . The maximum yield (90.28 t ha -1 ) was recorded from treatment combination of G 3 S 3 and the minimum yield (59.83 t ha -1 ) was recorded from treatment combination of G 0 S 1 . Therefore, 125 ppm GA 3 with 30 days old seedling was found suitable combination for tomato production. ©2017 Agriculture and Environmental Science Academy Citation of this article: Sarker, R., Ray, S.P., Paul, J., Nusrat, A. and Mallick, S.R. (2017). Interaction effect of seedling age and different doses of GA 3 on growth and yield of tomato (Lycopersicon esculentum Mill.). Archives of Agriculture and Environmental Science, 2(4): 301 -304, DOI: 10.26832/24566632.2017.020409