Agronomic characteristics of early-maturing soybean and breeding implications for Belgium

Belgian agriculture could decrease its heavy dependency on imported protein crops by a local production of soybean. Unfortunately, soybean production is hampered by Belgium's short and cold growing season. We evaluated 409 varieties, breeding lines and genebank accessions planted at two planting dates in a row-plot experiment to explore the genotypes that are suitable for growing in Belgium. The current MG000 varieties may require additional crossings with very early-maturing genotypes to guarantee an optimal and safe harvest. Within such crossings, care must be taken to maintain the indeterminate or semi-determinate growth habit. Vegetative development was negatively correlated with flowering date and maturity date, but positively correlated with cold tolerance. Seed quality was mainly affected by mould infection (associated with strong lodging and late maturity) and mottling caused by soybean mosaic virus. Planting 3 weeks earlier resulted in 8 d earlier flowering and 7 d earlier maturing, without significant losses in seed yield per plant. The results of this row-plot experiment hold promise to select for genotypes adapted to the Belgian conditions.