Effect of vermicompost and manure on morphological traits, yield and essential oil content of basil (Ocimum basilicum L.)

Organic fertilizers are valuable sources for improving soil quality and increasing crop yield. In order to evaluate the effect of vermicompost and manure application on morphological traits, yield and essential oil of basil (Ocimum basilicum L.), a field experiment was conducted in a randomized complete block design with eight treatments and three replications in Urmia city in 2019. The experimental treatments included control (T1), vermicompost [5 tons (T2), 10 tons (T3), 15 tons (T4), 25 tons per hectare (T5)], cow manure [10 tons (T6), 15 tons (T7) and 20 tons per hectare (T8)]. According to the results of ANOVA, the effect of the treatments on all studied traits was significant (p≤0.01). Results showed that T5 treatment increased plant height, number of leaves per plant, biological yield, seed yield, essential oil content and essential oil yield in comparison with control 67.81, 60.91, 53.36, 42.86, 109 and 72.95%, respectively. The highest number of lateral branches per plant (15.61) belonged to the T8 treatment, which was not significantly different from the T5. The T4 treatment had the maximum (45.66) flower number per plant among the treatments and this treatment was not significantly different from the T5 treatment. Also, the highest 1000-grain weight (2.72 g) was obtained from T4 treatment, which was in a same statistical group with T5 and T8 treatments. Overall, the results indicated that the application of vermicompost and cow manure had a favorable effect on morphological traits, yield and essential oil content of basil.