Author
Johnson, Richard | |
JOHNSTON, W - WASHINGTON STATE UNIV | |
BERTOLI, F - MONSANTO COMPANY | |
GOLOB, C - WASHINGTON STATE UNIV |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/6/2009 Publication Date: 1/1/2011 Citation: Johnson, R.C., Johnston, W.J., Bertoli, F.L., Golob, C. 2011. Seed yield, Development, and Variation in Diverse Poa Pratensis Accessions. Crop Science. 50:337-344. Interpretive Summary: Kentucky bluegrass (Poa pratensis L.) seed production for the U.S is primarily located in the inland Pacific Northwest including the states of Washington, Oregon, and Idaho. Kentucky bluegrass usually exhibits a sharp reduction in seed production the next year unless crop residue is removed after harvest. The most effective procedure for residue removal has been open field burning, but burning Kentucky bluegrass fields has become highly regulated and litigious. Previous work showed some accessions have little or no yield reduction with mechanical residue removal compared with the controversial practice of open field burning. Using 10 of these accessions, our objectives were to 1) relate yield and yield components in spaced plants to yield in solid seeded plots from previous research, 2) link plant production to growth and development factors and, 3) determine variation for seed production factors among accessions. This work showed that when yield per plant was estimated on a plant area basis it correlated with yield in solid seeded plots. It was also found that a longer plant development between heading and anthesis promoted yield and seeds per panicle. This findings could result in more efficient selection of spaced plants to promote yield under field conditions. Variation appeared sufficient for selection for yield and yield components in spaced plants for potential improvement of seed production for no-burn management systems. Technical Abstract: Post harvest residue removal is critical for continued high seed production of Kentucky bluegrass (Poa pratensis L.). Previous work showed some accessions have little or no yield reduction with mechanical residue removal compared with the controversial practice of open field burning. Using 10 of these accessions, our objectives were to 1) relate yield and yield components in spaced plants to yield in solid seeded plots from previous research, 2) link plant production to growth and development factors and, 3) determine variation for seed production factors among accessions. Yield, yield components, and developmental factors measured on spaced plants in 2002 and 2003 showed strong accession differences. Yields in solid seed plots from 1998 and 1999 data were consistently correlated yield area-1 of spaced plants (r=0.75, P<0.05, 2002, and r=0.90, , P<0.01, 2003). Turf quality was negatively correlated with yield area-1 in 2002 and 2003, but correlations of yield components with turf quality were not consistent between years. Days between heading and anthesis was the development factor most consistently correlated with yield area-1 (r=0.81, P<0.01, 2002 and (r=0.85, P<0.01, 2003). Variation among yield and yield components was significant among accessions in both 2002 and 2003. The results show that yield area-1 in spaced plants may be useful predictor of yield in solid seed plants and the importance of a long heading to anthesis period to promote seeds panicle-1. Variation appeared sufficient for selection for yield and yield components in spaced plants for potential improvement of seed production for no-burn management systems. |