Improving strawberry ‘Flamenco’ performance with nano-chitosan, PGPR and Trichoderma harzianum bio-capsules

A two-year study (2023-24 and 2024-25) assessed the effect of nano-chitosan, plant growth-promoting rhizobacteria (PGPR) and Trichoderma harzianum bio-capsule, individually and in combination on the growth, morphology and yield of strawberry (Fragaria × ananassa Duch.) cv. Flamenco in a subtropical environment. Among the treatments, T8 (nano-chitosan 100 ppm + Trichoderma harzianum (MTCC-5179) bio-capsule 200 ppm + PGPR Bio-capsule 200 ppm) was found to be significantly superior, achieving plant height (18.59 cm), leaves (20.68 plant-1), leaf area (87.74 cm²), runners (7.20 plant-1), crowns (2.78 plant-1), flowers (18.22 plant-1), fruit volume (19.16 cm³), diameter (43.81 mm), weight (18.55 g), length (56.95 mm), specific gravity (0.98 g cm-3), shelf-life (2.61 days) and yield (22.22 t ha-1) (p ≤ 0.05). The plants in this treatment exhibited a shorter time to bloom, with the first flowering observed on day 57.25 and fruit set (6.14 days after bloom) occurred soon after flowering. The PCA showed that the first principal component (PC1) explained 96.21 % of the variance integrating vegetative, reproductive and yield traits while the results of the Pearson correlation showed a strong positive association (r > 0.97) of the yield with morphological and fruit traits and a strong negative association (r < -0.96) with flowering delays. Concurrent application of nano-chitosan, PGPR and T. harzianum bio capsule has been established as an effective technology for strawberry vegetation, productivity, quality and postharvest performance under subtropical conditions.