Effect of Different Levels of Pruning and Nitrogen Fertilizer on the Quality and Quantity of the Volatile Oil of Rosmarinus officinalis L.

Abstract

The experiment was performed in a greenhouse belonging to the Department of Horticulture and Landscaping gardening, College of Agriculture, Tikrit University from November 2021 - May 2022. The experiment included two factors: the level of pruning (without pruning, moderate pruning, and severe pruning); the addition of nitrogen fertilizer at two levels (73.4 and 146.7 g N.L-1 in the form of urea (46% N) according to the randomized complete block design (RCBD). The results showed that the nitrogen fertilization treatment (F2) significantly excelled in the quantity of oil (2.505 g. 50 g plant-1) and the specific weight of the oil (0.907 g.ml-1) and an increase in the active substances (Cinol, Limonene, and α-Pinene), which amounted to (32.701, 4.476, and 8.407 mg. g plant-1).