Impacts of climate change on the widespread and epidemics of some tomato diseases during the last decade in Egypt

Abstract

This study explores some of the impacts that climate change, with warmer and more variable weather, may have on tomato diseases in Egypt. Its aim is to elucidate how warmer temperatures and an increase in extreme weather events may affect the incidence of some tomato fungal diseases in recent years. Recent climate trends, such as increased nighttime and winter temperatures, may be contributing to the greater prevalence of tomato diseases. The ranges of several important tomato disease in Egypt; including tomato late blight (the most destructive tomato disease causing fruit yield losses) have expanded since the early 1990s, possibly in response, in part, to climate trends. Wet vegetation promotes the germination of spores and the proliferation of fungi. Based on analysis of plant/disease/climate relations, an epidemic of late blight onset on tomatoes that is 1-2 weeks earlier means 2-3 additional sprays to achieve sufficient control of late blight. Accordingly, 1-3 more sprays will be applied at the incoming decades of the 2025-2100. The combination of long-term change (warmer average temperatures) and greater extremes suggest that climate change could have positive impacts on main tomato diseases in Egypt. There is a need for a better impact assessment of climate change on plant pests and diseases. In the Fourth Assessment Report of the IPCC4 these risks are insufficiently addressed.