Influence of cropping system on foot rot of winter wheat in France

Abstract

Wheat was assessed for foot rot and the responsible species ( Microdochium nivale, Fusarium spp.) identified at key stages on three different field trials: (a) the first comprised plots cultivated with cereals for a variable number of years after four years of non-cereals; (b) on the second, wheat was grown on compacted and uncompacted soil structure; (c) the third studied the effects of five wheat management techniques (sowing date and density, nitrogen fertilizer dose and form, removal/burial of cereal straw) on various sites. Microdochium nivale (which was predominant at early stages) and Fusarium spp. (which was predominant at later stages) were shown to behave very differently: the former was increased and the latter decreased where wheat was a previous crop, whereas foot rot as a whole was not affected by crop succession. Uncompacted vs compacted soil only increased foot rot at an early stage when M. nivale was predominant. Early sowing and high plant density (giving rise to low tillering) increased early foot rot and levels of M. nivale and decreased late foot rot and levels of Fusarium spp. A high vs low nitrogen rate and a low vs high ammonium content of the fertilizer increased foot rot; removal or burial of straw did not affect disease.