Field experiments with eleven spring wheat varieties released between 1971 and 1993 were carried out to assess genetic gain in yield potential and related variables (biomass, harvest index, kernels/spike, kernel weight and test weight). The genotypes tested were developed in the Quilamapu Wheat Breeding Program. Mexifén was the first enhanced variety of this group, and was used as the standard variety. The experiments were carried out at the Instituto de Investigaciones Agropecuarias, Chillán, Chile, from the season 1995 to 1998. Two similar experiments were carried out each year, with and without foliar fungus disease control to evaluate genetic gains and foliar diseases damage respectively. The overall average yields of all varieties tested, during 1995-1998, with and without fungicides were 9.02 t ha-1 and 7.50 t ha-1 respectively. Significative genetic gains in grain yield and related variables were not detected, with the exception of kernel weight, which presented an average genetic gains of 22.1 mg grain-1 year-1. It was concluded that the wheat varieties distributed between 1971 and 1993 did not show genetic gains in grain yield, and that the principal reason for the change of varieties was the genetic resistance to foliar diseases. |
ChileanJAR
