ARUSHA, TANZANIA -- Africa needs more research to address the information gaps on the impact of climate change on diseases, infections and epidemics caused by plant viruses, according to a study.
Researchers at the University of Western Australia conducted a review of existing literature, and found that the research gaps include a lack of climate change-scenario modelling for diseases caused by plant viruses, and little information on the effects of drought, flooding and heat waves on plant virus diseases.
'Only two [journal articles] out of 30 general reviews focused on viruses, with [research on] many aspects of viral pathosystems ― combination of host and the virus ― omitted,' said Roger Jones, one of the authors of the study and a plant pathologist at the University of Western Australia.
Jones, who was speaking at the 12th International Plant Virus Epidemiology Symposium (28 January–1 February) in Arusha, Tanzania, said that researchers should carry out more research to ascertain how climate change is contributing to plant diseases.
The review also shows that warmer temperatures reduce the effectiveness of control measures.
Increased temperatures enhance virus multiplication and evolution of virulent strains, increases the efficiency of vector transmission, and also reduces the ability to predict plant disease epidemics.
For instance, predicting the best time to target diseases-transmitting insects though pesticide spraying becomes more difficult.
But the review also found that hot, dry seasons decrease epidemics of aphid-borne viruses.
Joseph Ndunguru, the director of Mikocheni Agricultural Research Institute in Dar Es Salaam, Tanzania, agrees with calls for more research on the issue.
He says climate change has already led to an increase in numbers of plant disease-causing whiteflies (Bemisia tabaci) in East Africa, which results in crop losses estimated to be in the range of hundreds of millions of dollars.
'Whiteflies populations were [previously] very low, but the population has exploded suddenly due to climate change,' Ndunguru tells SciDev.Net.