There are two lodging control agents (plant growth regulators) available for grass seed producers in Oregon. Palisade (trinexapac-ethyl) and Apogee (prohexadione-calcium) plant growth regulators (PGRs) are acylcyclohexanedione inhibitors of the 3-β hydroxylation of GA. The known effects of the acylcyclohexanedione PGRs currently in use on grass seed crops are as follows:
Three closely related species of Festuca exhibiting fine leaf texture are commercially important turfgrasses and are known collectively as the fine fescues. These species are Chewings fescue (CF)[F. rubra L. subsp. fallax (Thuill.) Nyman], strong creeping red fescue (strong CRF)(F. rubra L. subsp. rubra), and slender creeping red fescue (slender CRF)[F. rubra L. var. littoralis (Vasey)]. While fine fescue species are morphologically similar in many characteristics, strong CRF and slender CRF produce rhizomes, but CF does not.
The stubble and straw remaining in grass seed fields after harvesting seed is known as residue. Post-harvest residue burning has been justified on the basis of pest control and stimulation of seed yield. Public concern over air quality and the potential for adverse health impacts on the region’s residents has necessitated the identification of alternative residue management practices. Recent Oregon legislation (SB 528) has, in effect, ended the practice of field burning in the state for most species except for the fine fescues. A better understanding of species-specific responses to residue management in the fine fescues will permit producers to choose the appropriate alternative practices should further restrictions become law.
Smoke plume from open-field burning in Oregon’s Willamette Valley. (T.G. Chastain photo)
