Influence of different levels of fertilizers and plant growth regulators on growth and yield characters of African marigold (Tagetes erecta L.)

Abstract

A field experiment was conducted during 2019-20 to study the effect of different levels of fertilizers and plant growth regulators on growth and yield characters of African marigold cv. ‘Pusa Narangi Gainda’. Three levels of fertilizers (100% RDF, 80% RDF and 60% RDF) and five different concentrations of plant growth regulators (water spray, 25 ppm GA3, 50 ppm GA3, 1 ppm Triacontanol and 2 ppm Triacontanol) were tested individually and in combinations in a Randomized Block Design with factorial concept (FRBD) and replicated thrice. The results revealed that among different fertilizer levels 100% RDF (NPK 250:100:100 kg/ha) resulted in maximum plant height at 25, 50, 75 DAT and at last picking (35.43, 55.92, 69.82 and 77.24 cm, respectively), number of primary and secondary branches (14.06 and 21.30, respectively) as well as plant spread (42.81 cm). Along with these, the yield attributes such as number of flowers per plant (64.86), flower yield per plant (318.26 g), per plot (2.79 kg) and per hectare (114.76 q) were found maximum with the same treatment. Among plant growth regulators, two times application (30 and 60 DAT) of 50 ppm GA3 resulted in maximum plant height at 50, 75 DAT and at last picking (58.43, 71.24 and 79.96 cm, respectively), maximum number of primary and secondary branches (14.92 and 23.00, respectively) as well as plant spread (45.49 cm). The yield attributes viz., number of flowers per plant (67.62), flower yield per plant (314.90 g), per plot (2.78 kg) and per hectare (114.49 q) were recorded maximum in the same treatment. The interaction between 100% RDF and 50 ppm GA3 was found best as it resulted in maximum plant height at 75 days after transplanting (74.87 cm) and at last picking (84.93 cm) as well as maximum number of primary and secondary branches (17.36 and 26.16, respectively), number of flowers per plant (73.23), flower yield per plant (377.30 g), per plot (3.31 kg) and per hectare (136.35 q). Thus, it can be concluded from the findings that application of 100% RDF with two times foliar application (30 and 60 DAT) of 50 ppm GA3 can significantly improve the overall plant growth and flower yield of African marigold.