Effect of environmental factors on pathogenic Fusarium in crops

Abstract

Fusarium pathogens from cultivated plants, including Fusarium oxysporum f. sp. elaeidis, agent of Fusarium wilt of oil palm, are species of phytopathogenic fungi found both in cultivated soils in temperate and tropical regions. They attack crops and cause significant economic damage. This review summarizes studies conducted on the effects of environmental factors on the development and infectious potential of these pathogenic Fusarium. Climate variables such as precipitation, soil and air humidity, sunlight and temperature are all factors that impact the development of Fusarium. The salinity of the air and soil acts directly or indirectly on their biology and life cycle. In high rate concentration, sodium chloride stimulates some Fusarium species whereas it causes a strong reduction in the density of other species. In addition, the chemical composition, microbial community and soil pH also modulate their development. Finally, mineral elements such as iron, manganese, zinc, calcium, potassium, sodium, and magnesium can induce resistance mechanisms in plants in response to attacks caused by Fusarium. This review shows that climatic factors act on the development of Fusarium. However, it should be noted that the effects of climatic factors may or may not be beneficial regarding the species. The same is true for pH, microbial communities, mineral elements and salts, mainly NaCl contained in soils, whose effects differ from one species to another. These results cannot therefore be extrapolated to Fusarium oxysporum f. sp. elaeidis-oil palm. Therefore, the collection of data that may allow the identification of the different factors acting on Fusarium oxysporum f. sp. elaeidis becomes relevant. Moreover, this knowledge would help to optimize screening tests for the selection of tolerant material and would allow better integrated management of fusariosis in plantations.