Efficacy of slow‐release and nano‐formulated antifungals against
Colletotrichum
spp.
: a multilevel meta‐analysis under contro
Junlong Feng, Hongyu Chen, Dong Zhao, Yang Zhang, Chenxun Gao, Shuqun Deng, Jiali Ning, Hui Han, Yan Han, Shuo Shen, Wei Li Abstract
BACKGROUND
Anthracnose, caused by Colletotrichum spp . , is a major constraint on crop production, and slow‐release and nano‐formulated fungicides are widely promoted as a way to improve control. How large and consistent this improvement is remains unclear, and previous syntheses treated multiple effect sizes per study as independent. We quantified the efficacy of slow‐release and nano‐formulated antifungals against Colletotrichum spp . in controlled experiments.
RESULTS
Thirty‐three studies contributed 266 effect sizes. In the primary subset (inhibition rate or control efficacy; 133 effect sizes, 18 studies), formulated products outperformed non‐encapsulated comparators, with a pooled natural logarithm of the response ratio (lnRR) of 0.42 (95% confidence interval (CI) 0.22–0.63), a ratio of means of 1.52. Heterogeneity was high ( I 2 = 93.9%), with 24% of total variance between studies and 70% among effect sizes within studies. The estimate was unchanged under cluster‐robust variance estimation, one effect size per study (0.38, 0.22–0.53), aggregation to study × concentration (0.38, 0.26–0.50) and exclusion of the largest study (0.39, 0.19–0.59). Carrier type, active‐ingredient class and experimental tier did not explain efficacy (Wald P = 0.088, 0.245 and 0.400) and jointly accounted for 13.9% of heterogeneity. Only one field trial was available, and prediction intervals included zero.
CONCLUSION
Nano‐enabled and slow‐release formulations improve antifungal efficacy against Colletotrichum under controlled conditions, but the effect is heterogeneous and essentially untested in the field. Standardized field trials and consistent reporting of formulation parameters are needed before efficacy claims can be extended to production. © 2026 Society of Chemical Industry.