Breeding of Nonflowering Orchardgrass, Dactylis glomerata L.1

Abstract

Among nearly 4,000 spaced plants in a breeding nursery of orchardgrass, Dactylis glomerata, 9 remained nonflowering near University Park, Pa., during the growing seasons of 1959, 1960, and 1961. Experiments with floral inductive treatments of 8, 10, 13, and 16 weeks of short days at 10 C or below subdivided selected clones from this nursery into three groups. Three 4‐clone synthetics with different cold inductive floral requirements were formulated. First‐generation (Syn 1) seed produced in 1963 at Prosser, Wash., of Syn A, Syn B, and Syn C, averaged, respectively, 50 g, 21 g, and 32 g per clone. The Syn 1 generation was compared with ‘Pennlate’ in solid‐seeded field plots for production of panicles and forage in the Northeast. In June 1965 Pennlate, Syn A, Syn B, and Syn C produced, respectively, 12.6, 13.1, 4.1, and 1.7 panicles per square foot in Pennsylvania and 37.2, 4.3, 1.8, and 0.6 in Vermont These data indicated a genetic basis for the nonflowering characteristic.