Response of Some Vegetative Growth Characteristics and Mineral Content of Albion Strawberry Plants to Spraying with Amino Acids, Ascorbic, and Naphthalene Acetic Acid

Abstract

The experiment was carried out inside the plastic house at the Agricultural Research and Experiment Station of the College of Agriculture, University of Kirkuk, Iraq. During the 2025/2026 growing season with the aim of showing the extent of the response of the vegetative growth characteristics and mineral content of strawberry plants of the Albion cultivars to foliar spraying with three concentrations of each of the amino acids (0, 4 and 8) ml L-1 and ascorbic acid (0, 150 and 300) mg L-1 and naphthalene acetic acid (0, 40 and 80) mg L-1. The plants were planted on 1/11/2026 on raised beds and the mulching process was carried out for the planting soil with black polyethylene nylon, alternately with a distance of 25 cm between plants, and sprayed with three sprays during the growing season starting from 1/12 with a difference of 30 days between sprays. The experiment was carried out according to a completely randomized block design for factorial experiments with three replicates and with 6 plants per experimental unit. The results showed that spraying with a concentration of 8 ml L-1 of amino acids significantly increased leaf area, number of leaves, chlorophyll content, nitrogen percentage, and carbohydrate content in the leaves, reaching (56.24 cm2, 15.09 leaves plant-1, 22.78 mg g-1 fresh weight, 3.483%, and 18.75%) respectively. Spraying with a concentration of 300 mg L-1 of ascorbic acid significantly affected leaf area, number of leaves, and chlorophyll and carbohydrate content, which reached (55.10 cm2, 14.65 leaves plant-1, 22.18 mg g-1 fresh weight, 18.46%) respectively. However, spraying with the growth regulator naphthalene acetic acid at a concentration of 80 mg L-1 significantly affected the number of leaves and the percentage of nitrogen, potassium, and carbohydrates in the leaves, which amounted to (14.69 leaves plant-1, 3.409%, 3.025%, and 18.29%) respectively. The bilateral and tertiary interactions between the concentrations of the factors included in the study had a significant effect on improving most of the studied Characteristics.