Selection for Early Flowering in Corn¹

Abstract

Three late, serai‐exotic corn ( Zea mays L.) synthetics were selected (5% level) for early silking by sib‐mating over a six‐generation period; then the seven cycles (including original forms) were compared in performance trials at three plant densities over 2 years. Virtually every ' trait measured changed significantly due to selection only for early flowering. Effect per cycle averaged: 1.00 q/ha yield increase; 1.2 points of percent H 2 O decrease; 2.8% stalk breakage increase; 7.2‐cm plant height decrease; 5.2‐cm ear height decrease; 1.8 days less to flower; and 0.3 days less silk delay. The decrease in silk delay suggests that the method may be useful in selecting materials for adaptation to high plant densities. We observed a maturity‐influenced cycle‐by‐year interaction for yield where early flowering cycles had a distinct advantage in a cool, short season.