Genetic and environmental factors influencing bacterial stalk rot in corn: a comprehensive study of resistance, epidemiology, and weather interactions

Background Dickeya zeae , the cause of bacterial stalk rot (BSR) is one of the important diseases after downy mildew which is often found infecting corn in Indonesia and has the potential to reduce corn yields. The use of resistant corn cultivars is believed to be an effective measure in suppressing BSR disease progression. This study aims to evaluate the resistance level of hybrid corn genotypes and determine the role of phytopathogen-corn genotype-environment interplay in BSR disease progression. Methods Resistance evaluation of hybrid corn genotypes was conducted under field conditions using artificial inoculation. Inoculation was performed by injecting a D. zeae suspension (10 8 –10 10 cfu/mL) into the second internode from the base of the corn stalk. Observed variables included disease incidence and severity, disease progression models, infection rate, area under the disease progress curve (AUDPC), protection index, Pearson’s correlation, and path analysis. Results Three of the nineteen hybrid corn genotypes consistently reacted as resistant or moderately resistant to BSR disease, namely A.26 × 14.12.1, A.26 × Mal.03, and B × Sy-01, with disease incidence and severity at 70%. The disease progression models in A.26 × 14.12.1; A.26 × Mal.03; and B × Sy-01 followed the Gompertz, Monomolecular, and Logistic models, respectively. Pearson correlation and path analysis revealed an interaction between weather factors in influencing the BSR disease progression, both positively and negatively. Based on the two analyses, it was seen that weather factors play a major role in various pathogen growth and progression processes, especially in the generative phase. In-depth and systematic validation of hybrid corn genotypes in suppressing BSR disease through epidemiological, metabolomic, and metagenomic approaches was needed to comprehensively confirm its ability.