Distribution of Airborne Fungal Propagule Concentrations in an Irrigated Cropland Zone

摘要

The composition of fungal propagules (spores, sporangia and hyphae) in the atmosphere was studied in a zone of irrigated cropland in the lower floodplains (Vegas Bajas) of the River Guadiana (Badajoz, SW Spain). The air was sampled once or twice per week from May to August in 1998 and 1999, using portable Burkard volumetric traps at ground level, in 10 farms producing tomato, beet, plum, pear, nectarine and/or rice. The mean total concentrations were between 3460 and 76 955 propagules/mpd. The genus Cladosporium was the most abundant, amounting to 75.3% of the propagule total. Other frequent types, in approximate order of their abundance, were Alternaria, Stemphylium, smooth Ustilago, hyphae, Oidium, basidiospores, Aspergillus, Torula, uredospores, Epicoccum and rough Ustilago. There were differences between farms which were explicable on the basis of the different crops and local conditions. For example, there seemed to be more airborne propagules where rice or beet was grown. The conditions neighbouring some farms, such as proximity to the river, also had a major effect on the temporal variation of the concentrations.