Crop management practices in the control of peanut diseases caused by soilborne fungi

The implementation of management practices that increase the natural populations of potential biocontrol agents may be a useful strategy in the control of diseases caused by soilborne fungi in peanut. The effects of rotation crops (maize, soybean, and peanut) and tillage systems (no tillage, reduced, and conventional tillage) on potential biocontrol agents and on the incidence of soilborne diseases were evaluated in two long-term field experiments at two sites located in the north and south regions of the peanut production area in Argentina. Native populations of actinomycetes, Trichoderma spp., and Gliocladium spp. were quantified from soil samples; the incidence of diseases caused by soilborne fungi was determined at peanut harvest. When maize was the preceding crop and crops were under conservation tillage, populations of biocontrol agents were higher in both trials. However, the relationship between cultural management and the incidence of root rot (strains of Fusarium solani) varied between the two field experiments, rot being lower when maize was the previous crop and peanut was under no tillage, and higher under the same management conditions at the other location. The quantification of native potential biocontrol agents (PBA) could be employed as a tool to determine the appropriate management strategies to be implemented for a sustainable control of peanut soilborne diseases. (C) 2007 Elsevier Ltd. All rights reserved.