Effect of nitrogen doses on growth and yield of marigold (Tagetes erecta L.) in subtropical climate of Nepal

Abstract

Marigold (Tagetes erecta L.) is a potential commercial flower with an increas- ing demand in Nepal every year. A field experiment was carried out to study the effect of different doses of nitrogen on growth and flower yield of marigold under container gardening at Bharatpur-11, Bhojad, Chitwan, Nepal during autumn 2018. Five treatments including different doses of nitrogen, i.e. (T₁-Control (0:90:75) kg NPK ha⁻¹; T₂-(45:90:75) kg NPK ha⁻¹; T₃-(90:90:75) kg NPK ha⁻¹; T₄-(135:90:75) kg NPK ha⁻¹; and T₅-(180:90:75) kg NPK ha⁻¹) were evaluated in Randomized Block Design with four repli- cations. Results showed that plant height, plant spread, and number of branches were statistically significant. Marigold plant applied with 180 kg ha⁻¹ nitrogen gave the maximum height (49.47 cm), spread (36.40 cm), and number of branches (24.75 plant⁻¹) in 45 DAT (days after transplanting) while the control plot showed the least. Similarly, nitrogen @ 180 kg ha⁻¹ was found to be effective for early flowering initiation (32.50 DAT) and days (41.25 DAT) compared to control (39 and 48.75 DAT, respectively) and also resulted in maximum number of flower (34.73 plant⁻¹), flower diameter (7.03 cm) and yield (22.29 t ha⁻¹) compared to other treatments. Thus, the overall results suggest that the application of 180 kg N ha⁻¹ in marigold produced the highest flower production.