Effects of nitrogen and potassium levels on growth and quality of pot-planted vicks cultivars (Plectranthus hadiensis var. tomentosu (Benth. ex E. Mey.) Codd) in Ho Chi Minh City

The study was conducted to determine the suitable dosages of nitrogen and potassium fertilizer for growth, quality and economic efficiency of Plectranthus hadiensis pot–planted. The experiment was carried out from April to June 2021 in the experiment field of faculty of Agronomy, Nong Lam University, Ho Chi Minh City. A two-factorial experiment was carried out in a completely randomized design (CRD) in three replications. The treatments consisted of 3 doses of nitrogen fertilizer (0.50; 1.00 (control) and 2.00 g N/pot) and 4 doses of potassium fertilizer (0.25; 0.50; 1.00 (control) and 2.00 g K2O/pot) in combinations. The results indicated that plants supplied with 0.50 g N/pot and 1.00 g K2O/pot gave the best results in terms of plant height (16.70 cm), stem diameter (5.45 mm), number of primary branches (10.09 branches/ plant), canopy diameter (20.37 cm), number of leaves (201.04 leaves/plant), leaf length and width (35.06 and 24.13 mm), duration on vase life (40.00 days), commercial pot ratio (94.67%). The revenue was 29,933 thousand VND per 1000 pots with the highest profit margin of 1.33 times at 60 days after planting.