Studies on the Effect of Plant Growth Regulators on Growth, Flowering and Xanthophyll Content of African Marigold (Tagetes erecta L.)

Production of marigold can be improved to a large extent by the judicious cultural operations i.e. application of optimum fertilizer at required time, crop management practices and use of plant growth regulators. Hence, an experiment was carried out in the Research Farm of Adhiparasakthi Horticultural College, Kalavai, during 2018-19 to find out the effect of plant growth regulators (NAA, GA3) and growth retardants (Maleic hydrazide, Alar) on growth and yield of African marigold var. Pusa Narangi Gainda. The experiment was conducted in randomized block design with three replications. Biometric observations on plant height, number of branches, number of leaves, leaf area, days to first flowering, flower head diameter, single flower weight, number of flowers per plant, flower yield per plant and Xanthophyll content were recorded at 90 days after planting and statistically analyzed. Results of the experiment revealed that among the growth hormones tested, considering the flower yield per plant, the treatment with NAA @ 150 ppm recorded for the maximum number of flowers with increased flower weight resulted in maximizing the flower yield (447.2 g plant-1) with xanthophyll content (18.80 kg-1 of petal meal (g)).