Effects of plant growth regulators on morphophysiology and yield of tomato

Abstract

Tomato (Solanum lycopersicum L.) is a major vegetable crop of Bangladesh and globally valued for its nutritional and economic importance. However, its yield potential is often limited by sub-optimal growth and physiological performance. Plant growth regulators (PGRs) such as gibberellic acid (GA₃), salicylic acid (SA), and methyl jasmonate (MeJA) play vital roles in regulating plant morphophysiology, flowering, fruit development, and yield. A field experiment was conducted during 2022–2023 at the research farm of Sher-e-Bangla Agricultural University, Dhaka, to investigate the effects of GA₃, SA, and MeJA, either alone or in combination, on tomato growth and yield. The experiment was laid out in a randomized complete block design with seven treatments and four replications. Results revealed that 20 ppm GA₃ significantly increased plant height (82.64 cm), whereas GA₃ combined with MeJA(20 ppm GA3 + 10 ppm MeJA) improved leaf number (54.59 leaves plant -1), SPAD value (54.09), flower clusters plant -1 (10.78), fruit diameter (16.03 cm), single fruit weight (52.87 g), number of fruits plant-1 (37.41), fruit weight plant-1 (kg) (2.91 kg), fruit weight plot-1 (17.77 kg) and the highest fruit yield ha-1 (70.86 t) while GA₃ combined with SA, MeJA combined SA or control produced the lowest yield (58.95 t ha⁻¹). These findings suggest that the combined application of GA₃ and MeJA is more effective than individual application or control, and may be recommended as a promising strategy to enhance tomato productivity under the edaphic and agro-climatic conditions of Bangladesh at Sher-e-Bangla Agricultural University (SAU). Res. Agric. Livest. Fish. 13(2): 275-284