Tolerance of Spring Triticale (× Triticosecale Wittmack) to Four Wheat Herbicides

Abstract

Triticale is a low input crop, produced in North America primarily for silage for animal feed. Currently, seed growers have few herbicide options for producing certified seed. There is anecdotal evidence that triticale tolerates many of the same herbicides as wheat. In 2004 and 2005, the tolerance of three spring triticale varieties (AC Alta, AC Ultima, and Pronghorn) was tested with four herbicides registered for wheat: florasulam + MCPA ester, clodinafop-propargyl, thifensulfuron-methyl/tribenuron-methyl, and sulfosulfuron-methyl + 2,4-D ester. Herbicides were applied at the label rate (1×) for wheat and twice (2×) that rate. Crop injury, plant height, biomass, and seed yields were quantified. Neither florasulam + MCPA ester, clodinafop-propargyl, nor thifensulfuron-methyl/tribenuron-methyl at 1× or 2× use rates significantly injured triticale. Sulfosulfuron-methyl + 2,4-D ester reduced triticale height at the 1× and 2× rates, as well as reduced biomass and yield at the 2× rate. Florasulam + MCPA ester, clodinafop-propargyl, and thifensulfuron-methyl/tribenuron-methyl do not cause significant crop injury and can be used for weed control in spring triticale, but sulfosulfuron-methyl + 2,4-D ester is not recommended for use in triticale.