Effect of different levels of pruning and nitrogen fertilizer on vegetative traits and chemical content 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 for the period 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), with three replicates and three plants for each experimental unit. The results showed that the treatment of severe pruning (H2) and moderate pruning (H1) were significantly superior in the trait of the branches number (26.65 and 24.61 plants.branches-1), respectively. The treatment without pruning (H0)) was significantly superior in the leaves content of chlorophyll of (0.36 mg.g-1). The nitrogen fertilization treatment of the first concentration (F1) had a significant effect on the trait of plant height, which amounted to 37.28 cm. As for the nitrogen fertilization treatment of the second concentration (F2), it was significantly superior in the percentage of nitrogen 1.31%, phosphorous 0.24%, and potassium 1.43%. As for the interaction, the treatment (S1H0) was significantly superior in the leaves content of chlorophyll, and the treatments (H0F1) and (H0F2) also gave a significant superiority in the leaves content of chlorophyll. The interference treatment (H2F2) also led to a significant superiority in the leaves content of phosphorous. As for potassium