Effect of different levels of nitrogen in combination with nano urea on growth, yield and quality of crossandra (Crossandra infundibuliformis L.) cv. Lakshmi

An investigation on the effect of different levels of nitrogen in combination with nano urea on growth, yield and quality of crossandra (Crossandra infundibuliformis L.) cv. Lakshmi was carried out in the Floriculture unit, Department of Horticulture, Faculty of Agriculture, Annamalai University, Chidambaram during the year 2022-2024. The experiment was laid out in Randomized Block Design with 14 treatments and 3 replications. Among the different treatments, the treatment T5 (100% PK + 75% N through urea + 0.4% Nano urea (3 sprays)) resulted in increased growth attributes such as plant height (85.21 cm), stem girth (7.95 cm), number of branches/plant (24.51), number of leaves/plant (99.29), leaf area (95.41 cm2) and chlorophyll content (0.840 mg/g). With regards to yield attributes, the treatment T8 (100% PK + 50% N through urea + 0.4% Nano urea (3 sprays)) showed early spike emergence (37.54 days), time taken for 1st flowering (44.83 days) with an increase in number of spikes/plant (36.27), spike length (14.21 cm) and number of flowers/spike (39.21). 100 flower weight (8.62 g), flower yield/plant (51.03 g), flower yield/plot (974.76 g/plot), estimated flower yield/ hectare (32.49 q/ha) and quality attributes like xanthophyll content (69.42 mg/g), carotenoid content (57.76 mg/g), shelf life of flowers (74.88 hours), longevity of flower in the plant (95.52 hours) and flowers with an excellent quality of visual scoring (9.16) were also observed the maximum in the treatment T8. The treatment control (T1) had the lowest value for all the growth, yield and quality attributes. Hence, it is concluded that the treatment T8 (100% PK + 50% N through urea + 0.4% Nano urea (3 sprays)) was found to be the best combination for improving the growth, yield and quality of crossandra cv. Lakshmi.