Evaluation of tillage and cover cropping systems on the overwintering of angular leaf spot, yield, and quality in dark tobacco

Angular leaf spot (ALS; Pseudomonas syringae pv. tabaci ) has become an increasingly important disease in dark tobacco [ Nicotiana tabacum L.] production since 2015. Current recommendations for controlling ALS include selecting dark tobacco varieties with low ALS susceptibility and using agricultural streptomycin. In the last decade, resistance to streptomycin has been documented, leaving tobacco producers with chemical options that offer limited efficacy. The objectives of this project were to evaluate the impact of tillage and cover crop types on ALS occurrence, tobacco yield, and leaf quality. Field plots were arranged in a split‐block design with four replications. Tillage type (conventional and no‐tillage) was applied to the main plot, and cover crop treatment (hairy vetch, crimson clover, cereal rye, and fallow) was applied to the subplots. Field inoculations of ALS were applied to separate dark tobacco trials in 2022–2023 and 2023–2024. Inoculated tobacco was terminated and left in the experimental area to serve as ALS inoculum for the subsequent tobacco crop the following year. Tobacco yield was reduced under no‐tillage production in both study years, but cover crop selection did not affect it. Disease progression was not statistically influenced by tillage or cover crop type during the second year of the first trial in 2023. However, conventional tillage reduced disease progression compared with no‐tillage in the second year of the second trial in 2024. Cover crop selection did not influence disease progression in this study. Additional research evaluating other control methods, particularly strip‐tillage and varietal resistance, should be conducted.