SOME PROPERTIES OF THE YIELD PREDICTORS OF COMPOSITE VARIETIES

Abstract

When the objective of developing composite varieties is to obtain a high yielding cultivar, yield prediction becomes important. This has been made with the formula VC = C-(C-V)/n in which VC is the average yield of the composite variety; V is the average yield of the n parental components and C is the average yield of their crosses. Another formula uses S1 (the average yield of the selfed progenies from the parental varieties) instead of V. The properties of these estimators, however, are still unknown. In this study an strategy to determine the yield that should be expected from a composite variety was designed and, with this as a reference, it was found that C-[(C-S1)/n] is an unbiased estimator of the yield of a composite variety whose variance is the same as the one from C-[(C-V)/n]. Two additional formulae are discussed.