Submitted to: Forage Focus
Publication Type: Popular Publication
Publication Acceptance Date: March 11, 2014
Publication Date: May 15, 2014
Citation: Grabber, J.H. 2014. Research seeks to improve the establishment and subsequent yield of alfalfa interseeded into silage corn. Forage Focus. pp. 6-7. Technical Abstract: This popular press article briefly describes the potential benefits of using prohexadione-calcium for enhancing the establishment of alfalfa interseeded into silage corn. Prohexadione sprayed in June with drop nozzles at 10 to 14 oz ai/A typically reduced alfalfa top growth by about 20% in July and doubled or tripled alfalfa seedling stand density by mid-October, compared to non-treated controls. First-year yields of alfalfa that were established the previous year by interseeding were two-fold greater than alfalfa conventionally spring-seeded after corn. Prior year prohexadione applications increased first-year alfalfa yields by about 12% and fall stand densities by 37 to 130%, compared to untreated interseeded controls. Alfalfa interseeding reduced silage corn yields by about 7%, and prohexadione application had no effect on corn yields. Thus, prohexadione application primarily improved stand density of interseeded alfalfa, and this should markedly improve the success rate of alfalfa establishment in corn and ensure high yields of alfalfa across several cropping seasons. Additional studies with prohexadione and other plant growth regulators are needed to find ways of lessening yield reductions in corn and to develop workable production systems for farms. Because alfalfa is often grown in rotation with corn, a workable interseeding production system could potentially be adopted on a substantial scale in the Midwest and other regions of the USA.