Recent developments in managing tuber blight of potato (Solanum tuberosum) caused by Phytophthora infestans

Abstract

Tuber blight, caused by Phytophthora infestans, occurs wherever potato (Solanum tuberosum) is cultivated and accounts for significant losses under field and storage conditions. After decades of research in late blight, there has been substantial progress, but numerous challenges remain for the management of tuber blight. The tuber blight disease components comprising of infection pathways, tuber resistance, cultivar interactions, pathogen transmission, and survival on tubers are highlighted in this article. New fungicide chemistries, novel approaches, and cultural measures are presented along with the implications of pathogen diversity, cultivar differences, and edaphic factors on tuber blight incidence and control. With the application of molecular genetic tools in potato breeding to identify novel sources of resistance, effective control of the disease using host resistance is more likely. However, there are key elements of tuber infection and management that still need to be addressed. The quantitative relationships of inoculum load to tuber blight incidence and P. infestans interactions with edaphic factors are undetermined. Forecasting or development of predictive models for tuber blight incidence under field and storage environments will greatly improve disease management. Furthermore, quantification and characterization of the interactions between P. infestans and other storage pathogens (bacteria and fungi) or soil microbes, and the evaluation of biocontrol agents or alternative approaches for control of tuber blight may lead to effective management of this disease.