Seedbed Residue and Seed Size Relationships in Winter Barley
1995
Chastain, Thomas G. | Ward, Kathy J. | Wysocki, Donald J.
Understanding how winter barley (Hordeum vulgare L.) seeds and seedling plants interact with crop residue in the seedbed is essential for development of planting recommendations for dryland conservation tillage systems. Field trials were conducted in 1990–1991 (Trial 1) and 1991–1992 (Trial 2) near Pendleton, OR, to determine the effects of seedbed crop residue, seed size, and cultivar on emergence, growth, and yield of winter barley. Seedbed residue cover (32–45%) did not affect seedling emergence rate in Trial 1. Seed-soil contact was apparently reduced in high-residue seedbeds, but emergence was reduced only when seed-zone water content was <120 g kg⁻¹ in Trial 2. More water was present in the seedbed at the time of seeding in Trial 1 than in Trial 2. Low-residue seedbeds were drier than moderate- or high-residue seedbeds at the time of seeding in both trials. Final stand density and subsequent plant growth were not influenced by seedbed residue (up to 49% residue) in either trial. Spike production was reduced by high residue and test weight was reduced by moderate and high residue in Trial 1. Grain yield and plumpness were lowest when barley was sown in low residue in Trial 2. Seedlings produced from large seeds emerged more rapidly and produced higher density stands than small seeds in Trial 1 but not Trial 2. Plants grown from large seed were somewhat larger in spring, but seed size had no other effect on growth or yield. Grain plumpness was greater in plants grown from large seed in Trial 1 but not Trial 2. No differences in stand establishment were detected among the cultivars tested. Higher seedbed residues should not be viewed as detrimental to achieving good winter barley performance in conservation tillage systems. Contribution of the Oregon Agric. Exp. Stn., Corvallis. Technical Paper no. 10453.
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