Effects of plant spacing, fertilizer, modified urea material and irrigation regime on herbage, oil yield and oil quality of rosemary in semi-arid tropical conditions

Abstract

SummaryField experiments were conducted in an area experiencing a semi-arid tropical climate to study the influence of plant spacings (45 30 cm, 45 45 cm and 45 60 cm), fertilizer levels (0, 10 t vermicompost, 5 t vermicompost + 150 : 25 : 25 kg N, P, K ha–1) and 300 : 50 : 50 kg N, P, K ha–1, modified urea material (Prilled urea and 20% (DCD) coated urea) and three soil moisture regime (0.25, 0.50 and 0.75 IW : CPE ratios – IW is the depth of irrigation water and CPE was the cumulative pan evaporation) on herbage, oil yield, oil content and oil quality of rosemary. Results revealed that closer plant spacing of 45 30 cm, application of 300 : 50 : 50 kg N, P, K ha–1, DCD coated urea and irrigation at 0.50 IW : CPE ratio produced maximum herbage and oil yields of rosemary. Content and quality of oil were not influenced by plant spacing, fertilizer or irrigation regime.