Climate change and plant pathogens


Climate change and plant pathogens

Plant pathology, or phytopathology, is the branch of botany that studies the diseases caused to plants by harmful organisms and the alterations of plants due to pollutants and physiopathologies caused by climatic or meteorological, pedological or nutritional factors.

The adversities responsible for plant diseases belong to different categories, being able to be from non-optimal natural factors or from biotic factors. Plant pathologies can be prevented or limited in their harmful effects, with agronomic interventions and defense against the cold which support mechanical, physical, biological and chemical control systems; the mechanical systems consist in the removal of the parts of the plant affected by the disease, in the direct elimination of the pests with various expedients and in the energetic brushing of the surfaces affected by superficial attacks by insects or cryptogams.

The physical systems include the use of fire to destroy pruning residues contaminated by harmful organisms, heat to disinfest seeds and bulbs and the use of colored adhesive traps, which exploit the attraction exerted on insects by certain colours; biological systems consist in using against harmful organisms other living organisms which are their natural enemies.

Chemical interventions, on the other hand, consist in administering appropriate pesticides, depending on the pathogen to be combated and on technical-economic choices. We will have fungicides, insecticides for fighting insects, acaricides against mites, nematicides against nematodes, molluscicides against molluscs, herbicides for parasitic or weed plants, rodenticides for rodents.

Integrated pest management consists of combining all available means of pest control for the protection of plants against harmful organisms. The Climate change and plant pathogens study, published in the Current opinion in microbiology, said: "Global food security is threatened by climate change, both directly through responses of crop physiology and productivity, and indirectly through responses of plant-associated microbiota, including plant pathogens.

While the interactions between host plants, pathogens and environmental drivers can be complex, recent research is beginning to indicate certain overall patterns in how plant diseases will affect crop production in future.

Here, we review the results of three methodological approaches: large-scale observational studies, process-based disease models and experimental comparisons of pathosystems under current and future conditions.We find that observational studies have tended to identify temperatures rising as the primary driver of disease impact.

Process-based models suggest that rising temperatures will lead to latitudinal shifts in disease pressure, but drying conditions could mitigate disease risk.Experimental studies suggest that rising atmospheric CO2 will exacerbate disease impacts. Plant diseases may therefore counteract any crop yield increases due to climate change."