Effect of GA ₃ , Triacontanol, and Humic Acid on Overwintering, Growth, Yield, and Fruit Quality of ‘Kent’ Strawberry Under Cold-Temperate Climates

Abstract A two-year study was conducted to investigate the effects of gibberellic acid (GA 3 ), triacontanol (TRIA), and humic acid (HA) on the overwintering success, growth, yield, and fruit quality of ‘Kent’ strawberries grown in a temperate climates. In Canada, particularly in regions such as Manitoba, the strawberry growing season is constrained by a short frost-free period and harsh winter conditions, which significantly impact plant growth and yield. This study aimed to evaluate the effects of foliar-applied biostimulators on strawberry growth and productivity under these challenging climatic conditions. Results indicated that triacontanol at 100 ppm consistently yielded the highest total and marketable yields, increased leaf area and chlorophyll content, and improved wintering index. These findings suggest that triacontanol enhances stress tolerance, productivity, and fruit quality. Gibberellic acid also promoted berry size and improved firmness, although to a lesser extent than triacontanol. Humic acid provided moderate benefits for growth and yield improvement. This study offers valuable insights into the potential of biostimulators to enhance strawberry productivity and fruit quality in cold-temperate climates, supporting the optimization of agronomic practices.