Evaluation of the combination of propamocarb hydrochloride and fluopicolide for management of black shank on tobacco

Phytophthora nicotianae, the causal agent of black shank, is responsible for huge yield losses and quality reduction in global tobacco production. Effective use of fungicides continues to be the major component in developing integrated disease management (IDM) programme. Infinito is an oomycete-specific fungicide that developed by Bayer CropScience, with a novel mode of action (active substances: propamocarb hydrochloride and fluopicolide). So far, limited information is available regarding the black shank control efficacy of Infinito in laboratory, greenhouse and field trials. Experiments were performed and our results showed that propamocarb hydrochloride, fluopicolide and their combination inhibited mycelial growth of P. nicotianae with EC50 values of 3.30, 0.20 and 0.06 mg L−1, respectively. In the greenhouse, Infinito reduced the disease incidence from 86.7% to 21.0% compared with untreated group. Besides the excellent ability to control black shank, Infinito also had a stimulating effect on tobacco seedlings growth. Similar results of field trials revealed that Infinito could not only reduce tobacco black shank incidence but also increase tobacco height, leaf area and yield. Consequently, the results indicate that Infinito is a new suitable fungicide for controlling tobacco black shank, offering a promising component in developing integrated programs for effective management of the disease.