Effect of maleic hydrazide and gibberellic acid on growth and yield of African marigold (Tagetes erecta l.) cv. Calcuttia Orange

A field experiment was carried out during the month of August – December 2020 at the Floriculture Development Center, Godawari, Lalitpur, Nepal. The experiment was conducted in randomized block design with seven treatments comprising of 3 levels each of maleic hydrazide (MH) (T2 : 200 ppm, T3: 300 ppm, T4 : 400 ppm) and gibberellic acid (GA3) (T5: 100 ppm, T6: 200 ppm, T7: 300 ppm) along with control (T1) replicated thrice with an objective to access the impact of MH and GA3 on production and productivity of African marigold (Tagetes erecta L.) cv. Calcuttia Orange. The foliar spray of the growth regulators was applied at 30 days after transplanting (DAT). The result revealed that vegetative growth viz. plant spread (2083 cm2), stem diameter (1.2 cm), number of primary (8.13) and secondary branches (28.27) was recorded significantly maximum with the treatment of MH at 400 ppm. The plant height (56.33 cm) was found to be maximum when treated with GA3 at 200 ppm whereas MH at 300 ppm resulted in highest number of leaves (139.26). First flowering (45 d), 50% flowering (50 d), full bloom (54 d), maximum flower weight (11.33 g) and maximum flower diameter (8.10 cm) were achieved with GA3 at 200 ppm. However, the maximum number of flowers (29) was obtained by the foliar spray of MH at 400 ppm. MH at 400 ppm resulted the maximum yield of the flowers (23.528 t ha−1) followed by GA3 at 200 ppm (23.079 t ha−1). The experiment concluded that MH at 400 ppm and GA3 at 200 ppm contributed to increased growth, flowering and yield of the crop.