A possibility of breeding of early soybean cultivars for low population densities

It is often considered that early soybean cultivars are characterized with limited branching and therefore require higher sowing rates (40 to 60 plants m-2). Development of cultivars adapted to lower population density (20 plants m-2) in 00 maturity group must result in greater yield stability, decrease dependence from uneven plant distribution and reduce seed expenses. Three-year germplasm study allowed identifying genotypes with yield tolerant to low population density. Main input to the adaptation to low population density is made by node number on main stem, branch number and pod quantity on lateral branches, and lateral racemes presence and expression. Multiple regression model of genotype ability to maintain yield in sparse crop on these parameters covered 47% of general variation.