Response of Teff, Barnyardgrass, and Broadleaf Weeds to Postemergence Herbicides

Abstract

Teff is a warm-season C4 annual grass crop grown for forage and food grain that has recently increased in production in parts of the United States. Hay from teff is well suited for livestock, especially horses. The objective of this study was to evaluate teff and weed response to selected herbicides in field studies conducted at the Malheur Experiment Station, Ontario, OR in 2009 and 2010. Herbicides were applied POST when teff was at the four-leaf stage. Broadleaf weed control at 21 d after treatment was greater than 91% across herbicide treatments. Only the premix of 2.5 g ai ha−1florasulam + 99 g ae ha−1fluroxypyr + 15 g ai ha−1pyroxsulam provided acceptable control of barnyardgrass. Due primarily to barnyardgrass competition, teff treated with a premix of 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam produced 7,200 kg ha−1of teff hay compared with 4,800 kg ha−1of teff hay for 2,4-D and dicamba and 4,200 kg ha−1teff hay when no herbicides were used. Teff grain production was greater with 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam compared with any of the other treatments. The use of a premix of florasulam + fluroxypyr + pyroxsulam would improve broadleaf and grass weed control in ‘Tiffany' and ‘Dessie' teff varieties, improve hay and grain yield, and reduce production costs.