Submitted to: Weed Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/7/2010
Publication Date: 2/16/2010
Citation: Anderson, R.L. 2010. Impact of Preceding Crop and Cultural Practices on Rye Growth in Winter Wheat. Weed Technology. 23:564-568. Interpretive Summary: A population-based approach to weed management has been developed that reduces the need for herbicides or tillage in crop production. One key to this approach is reducing seed production of weeds that escape control tactics and establish in the crop. This study showed that the preceding crop can influence how competitive winter wheat is with wild rye, a common weed in this crop. Rye seed production varied four-fold among preceding crops; oat/pea was the most favorable for winter wheat whereas soybean and spring wheat were less favorable. We also observed that tolerance to rye interference was improved by oat/pea. Yield loss due to a uniform infestation of rye was three-fold higher following soybean or spring wheat than oat/pea. Producers can affect weed management by their choice of crop sequencing.
Technical Abstract: Improving crop vigor can suppress growth of weeds present in the crop. This study examined the impact of preceding crop and cultural practices on rye growth in winter wheat. Preceding crops were soybean, spring wheat, and an oat/dry pea mixture. Two cultural treatments in winter wheat were also compared, referred to as conventional and competitive canopies. The competitive canopy differed from the conventional in that the seeding rate was 67% higher and starter fertilizer was banded with the seed. The study was conducted at Brookings, SD. Rye seed and biomass production differed fourfold among treatments, with winter wheat following oat/pea being most suppressive of rye growth. Rye produced 63 seeds/plant in winter wheat with a competitive canopy that followed oat/pea, contrasting with 273 seeds/plant in conventional winter wheat following spring wheat. Yield loss in winter wheat due to rye interference increased with rye biomass, but winter wheat was more tolerant of rye interference following oat/pea compared with the other preceding crops. Regression analysis indicated that winter wheat yield loss at the same rye biomass was threefold higher following spring wheat or soybean compared with oat/pea as a preceding crop. Winter wheat competitiveness and tolerance to rye can be improved by increasing the seeding rate, using a starter fertilizer, and growing winter wheat after an oat/pea mixture.