Relationship between cropping frequency, root rot and yield of silage maize on sandy soils.

Abstract

In field trials at Wageningen in 1979-86, forage maize cv. Dorina was given 100 t cattle slurry/ha and grown in a long (sugarbeet/1 or 2 years barley/potato/maize) or short (potato/maize) rotation, or continuously cropped. Nematicides were applied to each crop in all rotations. The effects of soil treatment with pencycuron, benomyl, metalaxyl or gamma -irradiation were studied in 1986 in pot experiments using soil from the field trial plots for each cropping sequence. Roots were given a healthiness ranking in each year. Yields were 10-20% lower with continuous cropping and a prolonged short rotation. Neither annual applications of slurry nor nematicides reduced the adverse effects of continuous cropping. Continuous cropping stimulated root rot. There was a close negative relation between cropping frequency, incidence of root rot and maize yield. Root rot seemed to be caused mainly by Pythium spp., and seemed to occur more seriously in years when the first half of the growing season was wetter than normal. (Abstract retrieved from CAB Abstracts by CABI’s permission)