Influence of crop rotation and tillage on incidence of brown root rot of peanut caused by Fusarium solani in Argentina

Brown root rot caused by Fusarium solani is one of the most important diseases of peanut in Argentina. The influence of crop rotation and tillage practices on diseases caused by Fusarium spp. has been widely reported ill other crops. A field experiment was conducted from the 2001-2002 to the 2005-2006 agricultural year to determine whether crop rotation and tillage had any influence oil the incidence of brown root rot. Crop rotation included corn (Zea mays), peanut (Arachis hypogaea), and soybean (Glycine max). Corn and soybean were always seeded in a no-till system, whereas peanut was grown under four different tillage systems (disk harrow, chisel plow, no-till, and paratill subsoiler). Soil mechanical impedance (MPa), disease incidence, and yield were measured in peanut Plots under each tillage system. Use of a paratill subsoiler before seeding peanut ill the no-till system generally reduced the subsurface layer of compacted soil, which provided a favourable environment for root growth and, consequently, reduced disease incidence. Furthermore, reduction of root rot incidence was greater ill a 2-year rotation, including corn-soybean or soybean-corn prior to peanut, than in a 1-year rotation. Incidence of brown root rot with different tillage systems 2 weeks before harvest showed a strong inverse linear relationship with pod yield. The use of a paratill subsoiler before seeding peanut in a no-till system could be a Suitable strategy to improve peanut root growth and reduce disease incidence, which provides a promising alternative in the control of root rot in the Southern production region of Argentina.