Abstract
Variation in crop-weed interference relationships has been shown for a number of crop-weed mixtures and may have an important influence on weed management decision-making. Field experiments were conducted at seven locations over 2 yr to evaluate variation in common lambsquarters interference in field corn and whether a single set of model parameters could be used to estimate corn grain yield loss throughout the northcentral United States. Two coefficients (I and A) of a rectangular hyperbola were estimated for each data set using nonlinear regression analysis. The I coefficient represents corn yield loss as weed density approaches zero, and A represents maximum percent yield loss. Estimates of both coefficients varied between years at Wisconsin, and I varied between years at Michigan. When locations with similar sample variances were combined, estimates of both I and A varied. Common lambsquarters interference caused the greatest corn yield reduction in Michigan (100%) and had the least effect in Minnesota, Nebraska, and Indiana (0% yield loss). Variation in I and A parameters resulted in variation in estimates of a single-year economic threshold (0.32 to 4.17 plants m-1 of row). Results of this study fail to support the use of a common yield loss-weed density function for all locations.
Original language | English (US) |
---|---|
Pages (from-to) | 1034-1038 |
Number of pages | 5 |
Journal | Weed Science |
Volume | 52 |
Issue number | 6 |
DOIs | |
State | Published - 2004 |
Keywords
- Bioeconomic model
- Common lambsquarters
- Corn
- Interference
- Yield loss