Less Height, Lower Yield

Growing winter wheat for both grain and straw production is common on poultry farms in the U.S. mid-Atlantic region, where grain is used for feed and straw for animal bedding. Grain yield can be improved by spraying plants with a regulator that halts vertical growth and makes them less prone to falling over, a phenomenon farmers call “lodging” that can greatly reduce grain yields.

However, the effect of growth regulators on straw yield and quality was unknown, so a team of researchers in the college, led by Daniela Carrijo, assistant professor and extension specialist in grain crop production, studied the effect of a growth regulator in combination with nitrogen fertilizer applied at different rates.

Over two years, the researchers tested nine combinations of three nitrogen fertilizer amounts and three trinexapac-ethyl growth-regulator treatments. They found that trinexapac-ethyl reduced plant height but did not increase stem thickness, leading to slightly lower straw yield.

Their results indicated that trinexapac-ethyl did not alter straw quality or absorbency, leaving unchanged the amount of water the straw could hold—meaning it could still be used for animal bedding.

The researchers published their findings in Crop, Forage & Turfgrass Management.

—Jeff Mulhollem