Airborne fungi cause more crop diseases and damage to major crops – such as rice, potato, tomato and ginger – than bacteria and viruses, says a study by Indian Institute of Technology Madras researchers1.
Rising temperatures, they add, might increase the prevalence of fungal diseases, which are likely to extend to the Himalayan regions and the Western Ghats, where rare and important medicinal plants grow.
Microorganisms, spread as suspended particles in the air, are called bioaerosols. Airborne crop pathogens such as bacteria and viruses have been widely studied. The roles of fungi in crop diseases, however, remain largely unexplored.
To find out, the scientists, led by Sachin S. Gunthe, gathered data from media reports, official reports, online summaries, and local observers between 1998 and 2018. This led to the generation of a dataset of more than 4,000 records of fungi-related crop diseases in India.
They found that 69 disease-causing fungal attacks negatively affected 39 different crops over the past 20 years. During this period, the fungal species Puccinia striiformis affected wheat crop on 12 occasions. This is in addition to the impact of other disease-causing fungal species to wheat. Nine different fungal species, including Pyricularia oryzae , were found to affect rice crops.
The fungal species Phytophthora infestans destroyed crops such as potato, tomato and ginger at 14 locations across India.
The fungal disease prevalence has been linked to the mixing of surface air with upper-boundary layer air, increasing the fungi-containing bioaerosol concentration. The bioaerosol concentration peaks in January, but starts decreasing from February.
1. Yadav, S. et al. Bioaerosol impact on crop health over India due to emerging fungal diseases (EFDs): an important missing link. Environ. Sci. Pollut. Res. (2020) doi:10.1007/s11356-020-08059-x