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Book of Abstracts First Legume Society Conference 2013: A Legume Odyssey Novi Sad, Serbia, 9-11 May 2013
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Yield stability in varietal mixtures of faba bean, Vicia faba
Georg Carlsson 1 , Erik Steen Jensen 1 , Nawa Raj Dhamala 1 , Kerstin Huss-Danell 2 , Mårten Hetta 2 ,
Ann-Charlotte Wallenhammar 3
1 Swedish University of Agricultural Sciences, Dep. Biosystems and Technology, Alnarp, Sweden
2 Swedish University of Agricultural Sciences, Dep. Agricultural Research for Northern Sweden, Umeå, Sweden
3 Rural Economy and Agricultural Society, Örebro, Sweden
Spatial and temporal variation in growth and N 2 fixation poses problems for the sustainability of
legume cropping systems. In varietal mixtures, complementary tolerance to biotic and/or abiotic
stress may lead to higher yield stability, while heterogeneity in chemical composition may be a
potential disadvantage for the quality of harvested products. To investigate the potential benefits
of legume varietal mixtures, three varieties of faba bean, Vicia faba, were cultivated in field as
single varieties and in two- and three-varietal mixtures. The field experiments were replicated at
three locations during two years. Harvest of whole-crop forage was performed in parts of the
experimental plots at pod-fill, and grain harvest was performed at full maturity. Samples from
both harvest occasions were used for analyses of product quality and N 2 fixation. Occurrence of
the fungal pathogen Botrytis fabae, causing chocolate spot disease, was estimated by repeated visual
grading in the field plots and complemented by DNA-based quantification of B. fabae infections
in sampled leaves. Several of the varietal mixtures had as high grain yields as the highest-yielding
single varieties, and spatial variations in yield were often lower in varietal mixtures. One of the
highest-yielding single varieties also showed high occurrence of chocolate spot disease.
Combining this apparently disease-sensitive variety with other varieties reduced the disease
occurrence without compromising the high yield level. This holistic study highlights the benefits
that cropping systems diversification can provide as a strategy to prevent disease outbreaks and
improve yield stability in legumes.
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