Effect of Carbon Dioxide on Multiplication of Fusarium in Soil

Abstract

NUMEROUS studies have been made on the effects of carbon dioxide on fungal growth in pure culture, and on substrates other than soil. Since soil is the natural habitat of many fungi, and frequently has carbon dioxide-levels exceeding that present in normal air, it is important that effects of carbon dioxide-enriched air on fungal behaviour in soil be investigated. With the exception of work by Lundegårdh¹ using sterile soil and Fusarium species, there is little information available on the effects of carbon dioxide on fungal behaviour in soil. Recently, techniques have been developed² for studying Fusarium multiplication in natural soil, as indicated by sporulation and increase in number of colonies on soil dilution plates. It was found that carbon dioxide at levels of 2–25 per cent in air for 16–42 hr. frequently stimulated multiplication of Fusarium oxysporum f. cubense ³. Studies were initiated with other Fusarium species and with carbon-14 dioxide to determine the action of carbon dioxide in stimulating Fusarium multiplication. The soil-plate technique² was used for studying the effect of carbon dioxide tension on Fusarium population as determined by soil dilution plating.