WEED CONTROL DECISION RULES UNDER UNCERTAINTY

A model of weed control, which took into account the stochastic nature of crop price, yield, and weed density, was developed to assist farmers in determining weed densities that justify herbicide application and the optimal rate of application. In an application of cocklebur control in soybeans, it was found that the value of following the "if-then-else" treatment strategy versus a fixed application rate regardless of weed density was approximately $25 per acre at low weed numbers. Profits of the marginal treatment strategy are higher than the "if-then-else" strategy, but may not be sufficient to cover the additional informational costs. Under both strategies, the total amount of herbicide applied decreases with increases in uncertainty under the assumption of risk neutrality. The result is due to the convex relationship between weed density and yield loss. Under the assumption of maximizing expected utility, there are instances in which herbicide use increases with risk aversion as per conventional wisdom.

[1]  Roy J. Smith,et al.  Weed Thresholds in Southern U.S. Rice, Oryza sativa , 1988, Weed Technology.

[2]  Gershon Feder.  Pesticides, Information, and Pest Management under Uncertainty , 1979 .

[3]  David J. Pannell,et al.  An economic response model of herbicide application for weed control. , 1990 .

[4]  A. Hallam.  The competitive firm's response to risk , 1987 .

[5]  Pest Information Markets and Integrated Pest Management , 1981, Journal of Agricultural and Applied Economics.

[6]  W. Deen,et al.  Evaluation of Alternative Decision Rules for Postemergent Herbicide Treatments in Soybean , 1992 .

[7]  Kent D. Olson,et al.  A Farmer's Choice of Weed Control Method and the Impacts of Policy and Risk , 1992 .

[8]  C. J. Doyle,et al.  A model of the economics of controlling Alopecurus myosuroides Huds. in winter wheat , 1986 .

[9]  U. Regev,et al.  Optimal Agricultural Pest Management with Increasing Pest Resistance , 1974 .

[10]  R. Raskin,et al.  INTERPRETATIONS AND TRANSFORMATIONS OF SCALE FOR THE PRATT-ARROW ABSOLUTE RISK AVERSION COEFFICIENT: IMPLICATIONS FOR GENERALIZED STOCHASTIC DOMINANCE: REPLY , 1986 .

[11]  G. A. Norton,et al.  Analysis of decision making in crop protection , 1976 .

[12]  Roger D. Cousens,et al.  An empirical model relating crop yield to weed and crop density and a statistical comparison with other models , 1985, The Journal of Agricultural Science.

[13]  Darwin C. Hall,et al.  APPLICATION OF THE ECONOMIC THRESHOLD FOR INTERSEASONAL PEST CONTROL , 1985 .

[14]  Roger D. Cousens,et al.  The effect of weed distribution on predictions of yield loss. , 1990 .

[15]  J. Miranowski.  Estimating the Relationship between Pest Management and Energy Prices, and the Implications for Environmental Damage , 1980 .

[16]  Roger D. Cousens,et al.  The use of Biologically Realistic Equations to Describe the Effects of Weed Density and Relative Time of Emergence on Crop Yield , 1987, Weed Science.

[17]  INFORMATION VALUE IN WEED MANAGEMENT , 1990 .

[18]  Richard H. Day,et al.  Probability Distributions of Field Crop Yields , 1965 .

[19]  M. Marra,et al.  A COMPUTABLE ECONOMIC THRESHOLD MODEL FOR WEEDS IN FIELD CROPS WITH MULTIPLE PESTS, QUALITY EFFECTS, AND AN UNCERTAIN SPRAYING PERIOD LENGTH , 1989 .

[20]  W. Musser,et al.  OPTIMAL AGRICULTURAL PEST MANAGEMENT WITH MULTIPLE SPECIES , 1985 .

[21]  L. Moffitt,et al.  Economic Thresholds Under Uncertainty with Application to Corn Nematode Management , 1984, Journal of Agricultural and Applied Economics.

[22]  L. Moffitt.  Incorporating Environmental Considerations in Pest Control Advice for , 1988 .

[23]  Risk Efficient Action Thresholds for Nematode Management , 1988 .

[24]  C. Tisdell,et al.  Economic thresholds and response to uncertainty in weed control , 1987 .

[25]  R. Blackshaw.  Resolving economic decisions for the simultaneous control of two pests, diseases or weeds , 1986 .