Effects of Pinching, Foliar Spraying with Benzyladenine and NPK on Selected Vegetative Growth Characteristics and the Chemical Composition of Myrtus communis L. Leaves

• Mohammed Ali Musa Al-Qaisi1*, Mateen Yilmaz Izaldin Al-Bayati1

  Author

The experiment was conducted from 5 May 2025 to 30 Jun 2026 at the Nursery of the Department of Horticulture and Landscape Design, College of Agriculture, Kirkuk University, Iraq. The experiment was designed as a factorial experiment in Randomized Complete Block Design (RCBD) with three replications. The treatments were two pinching levels (non-pinched and pinched), three BA levels (0, 75, and 150 mg L⁻¹), and three NPK fertilizer levels (0, 5, and 10 g L⁻¹). At the end of the experimental period, growth and chemical parameters, including lateral branch diameter, number of lateral branches, total chlorophyll content, and leaf N percentage, were measured. The results showed that all factors significantly affected the traits studied. Vegetative growth was usually better for the pinched plants than for the non-pinched plants. Similarly, branch diameter, number of branches, chlorophyll content, and leaf N concentration were significantly increased with increasing BA concentration and NPK fertilizer level. All evaluated characteristics were highest when the combined effect of pinching, 150 mg L⁻¹ BA, and 10 g L⁻¹ NPK was used, suggesting a synergistic effect among the treatments. The reasons for these improvements included increased lateral bud development, increased cell division, improved photosynthetic efficiency, and nutrient uptake and utilization. The study shows that pinching combined with foliar application of 150 mg L⁻¹ benzyladenine and 10 g L⁻¹ NPK is an effective horticultural technique for enhancing vegetative growth and the nutritional quality of the leaves of Myrtus communis L. and is highly recommended for commercial nursery production and landscaping.

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