Three-Year Assessment of the Effects of Compost Tea on Yield and Qualitative Parameters of Gold Kiwifruit

Compost-derived products are increasingly used to enhance soil biological activity and plant performance in perennial fruit systems, but the effects of compost tea (CT) in kiwifruit orchards remain unexplored. This study assessed root-zone applications of aerated CT from 2023 to 2025 on the yield and fruit quality of gold kiwifruit in a commercial pergola-trained orchard. Two treatments were compared: weekly CT fertigation during summer and an untreated control (Ctrl). Yield, fruit number, mean fruit weight, and fruit quality—hue angle (H°), firmness, soluble solids content (SSC), and dry matter were evaluated annually. The CT application did not significantly affect total yield or fruit number over three seasons. However, it increased the mean fruit weight and shifted fruit distribution toward larger size classes. Fruit quality responses varied: CT-treated fruits initially showed lower firmness and SSC, but in the final year, firmness and SSC matched controls. Dry matter content was higher in CT fruits (18.87%) than in controls (16.71%). These results indicate that during the early to mid-bearing phase, CT promotes fruit growth toward larger sizes and enhances dry matter accumulation. Gradual benefits appeared after three annual applications, suggesting CT is a promising tool for medium- to long-term soil and rhizosphere management in kiwifruit.