Nghiên cứu ảnh hưởng của khoảng cách trồng và liều lượng đạm đến năng suất, chất lượng dược liệu cỏ nhọ nồi (Eclipta prostrata L.)

Abstract

The study aimed to determine the appropriate planting density and nitrogen fertilizer application rate for Eclipta prostrata to achieve high yield and medicinal quality. The experiment consisted of 9 treatments with 3 replications, arranged in a split - plot design. The main plots were planting distances: K1: broadcasting at 10 cm spacing, K2: planting at 10 × 10 cm spacing, and K3: planting at 10 × 15 cm spacing. The subplots were nitrogen fertilizer levels: P1: 80 kg N/ha, P2: 100 kg N/ha, and P3: 120 kg N/ha. The results showed that denser planting tended to increase plant height  with the maximum height (66.55 cm) obtained from broadcasting at 10 cm spacing. At a spacing of 10 × 15 cm, stem diameter (4.52 mm) and the number of primary branches (13.26 branches) were the highest. Similarly, with the highest nitrogen application rate of 120 kg N/ha, plant height (62.13 cm), stem diameter (4.03 mm), and number of primary branches (12.91 branches) reached the maximum values. The highest actual yield (3.80 tons/ha) was obtained in the treatment with broadcasting and 120 kg N/ha application. The wedelolactone content was the highest in application rate of 100 kg N/ha (0,21%).