The Impact of Mycorrhizal and Azospermum Inoculation, Along with Different Irrigation Levels, on Certain Physiological Characteristics of Strawberry Plants

Abstract

Abstract The aim of this study was to assess how inoculation with mycorrhizal fungi and Azospirillum bacteria affects physiological characteristics of strawberry plants under drought conditions and grown in mixed soil. Strawberry seedlings were planted individually in 5 kg pots filled with mixed soil, and urea fertilizer (20% K, 20% P, 20% N) was applied at planting. Irrigation was carried out after planting, based on predetermined treatments, replenishing water when pots lost 50% of their initial weight. The experiment, consisting of six replicates for each treatment, recorded the water added to calculate total water consumption. Results indicated: The interaction between mycorrhizae and Azospirillum showed positive outcomes, with chlorophyll content in leaves averaging 20.23 SPAD units in the treatment. This increase is attributed to Azospirillum’s role in nitrogen fixation, leading to enhanced nitrogen availability for plants. Chlorophyll percentage decreased as irrigation levels increased, ranging from 17.63 to 20 for 100% and 50% irrigation levels, respectively. Phosphorus absorption increased by 1.93% at the flowering stage (40 days) when inoculated with bacteria, but decreased by 2.68% at full maturity (80 days). Potassium absorption increased by 13.39% at the flowering stage and reached 6.20% at full maturity when inoculated with bacteria, likely due to the secretion of growth regulators like auxins and cytokinins. Significant differences were observed in the chemical content of strawberry leaves regarding abscisic acid (ABA), salicylic acid (SA), and proline. ABA concentration was highest (98.14 micrograms/ml) at the first irrigation level without mycorrhizae, while SA had the lowest concentration (13.10 micrograms/ml). At the first irrigation level with mycorrhizae, SA concentration was higher than ABA, reaching 57.04 micrograms/ml, while ABA concentration was 15.25 micrograms/ml.