Agronomic Comparison of Dwarf and Conventional Height Oat Genotypes1

Abstract

Development of dwarf stature cultivars has contributed to higher grain yields in wheat (Triticum aestivum L.) and rice (Oryza sativa L.). Although dwarf stature oat (Arena sativa L.) germplasm is available, most oat breeders have not used it in the past because straw yield has traditionally been considered an important agronomic trait. Comparisons of the agronomic performance of dwarf and conventional height genotypes are needed in order to better define the potential value of incorporating dwarf stature into future oat cultivars. From 1982 to 1984 at St. Paul, MN, four experimental dwarf oat genotypes (MN 795929, MN 805928, MN 81160 and MN 82214) were compared with four conventional height genotypes (‘Moore’, ‘Goodland’, ‘Ogle’, and MN 80116) for grain and straw yields, as well as other agronomic characteristics. Plant populations for these studies ranged from 210 to 480 plants m−2. The 1984 experiment was conducted under especially high nitrogen fertilization. There were no differences in grain yield between the dwarfs and conventional height genotypes in 1982 and 1983. The highest yielding dwarf genotype in 1984 produced significantly less grain than the best conventional cultivar. Overall, straw yields of the dwarfs ranged from 73 to 125% of the conventional height lines. However, the highest grain yielding dwarfs in each year had straw yields only about 80 to 90% as high as the highest grain yielding conventional cuitivars. These proportional straw yield differences existed whether the crop was harvested at ground level or at a 15 cm stubble height. Harvest indexes for the highest yielding dwarfs were similar to the conventional height genotypes, even though the dwarfs were about 30% shorter in stature. Panicles of the dwarfs characteristically exserted only partially from the flag leaf sheaths, although this characteristic is being corrected through additional breeding. Such future dwarf lines should be well adapted to intensive management conditions because of their resistance to lodging and may ultimately provide higher grain productivities than can be achieved with conventional height cultivars.