Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2009
Publication Date: 1/4/2010
Citation: Casler, M.D., Johnson, R.C., Barker, R.E., Jenderek, M.M., Papadopolous, Y.A., Cherney, J.H. 2010. Feasibility of Seed Production from Non-flowering Orchardgrass. Crop Science. 50:35-42.
Interpretive Summary: Development of new varieties of non-flowering orchardgrass would greatly simplify management of orchardgrass in pastures because flowers and stems are a nuisance to grazing livestock. However, commercialization of this concept will require that non-flowering plants be able to produce somewhere in the world. We discovered plants that are capable of flowering and seed production at locations with very mild winters. These plants did not flower over a two-year period in a cold-winter climate, demonstrating the feasibility of this concept. These results have huge potential to improve the management flexibility for producers using rotational grazing systems.
Technical Abstract: Non-flowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems. Our objective was to quantify seed production on non-flowering orchardgrass clones selected in cold-winter climates, but grown for seed in mild-winter climates. We evaluated 98 orchardgrass clones for seed production traits at four locations: Pullman and Central Ferry, WA; Corvallis, OR; and Parlier, CA. Most plants (~92%) flowered at the three northern locations, but only 38% flowered at Parlier, which may have a winter that is insufficiently cold for adequate floral induction and vernalization. Among non-flowering plants that flowered at the three northern locations, number of panicles and plant seed yield were reduced by 64% relative to that of two check cultivars. Mean panicle number was lowest (11%) for plants selected at Ithaca, NY, the selection location with the warmest winter conditions, and highest (37%) for plants selected at Charlottetown, PEI, the selection location with the coldest winter conditions. These results confirm our expectations that the most desirable plants (non-flowering under cold winters and normal flowering under mild winters) should arise from selection under more severe winter conditions. Intensive selection identified five clones with high and stable seed production at all three northern locations, averaging only 12% fewer panicles, but 54% higher panicle seed yield and 24% higher plant seed yield compared to check cultivars. These results provide proof-of-concept that some orchardgrass plants are capable of dual phenotypic expression, flowering in mild-winter climates or expressing the non-flowering trait in cold-winter climates.