Stability of corn (Zea mays)-velvetleaf (Abutilon theophrasti) interference relationships
1996
Lindquist, J.L. | Mortensen, D.A. | Clay, S.A. | Schmenk, R. | Kells, J.J. | Howatt, K. | Westra, P.
The crop-weed interference relationship is a critical component of bioeconomic weed management models. Multi-year field experiments were conducted at five locations to determine the stability of corn-velvetleaf interference relationships across years and location. Two coefficients (I and A) of a hyperbolic equation were estimated for each data set using nonlinear regression procedures. The I and A coefficients represent percent corn yield loss as velvetleaf density approaches zero, and maximum percent corn yield loss, respectively. The coefficient I was stable across years at two locations, but varied across years at one location. The coefficient A did not vary across years within locations. Both coefficients, however, varied among locations. Results do not support the use of common coefficient estimates for all locations within a region.
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