An Economic Analysis of Control of the Western Corn Rootworm Variant across Indiana

A variant of the western corn rootworm (CRW) has adapted to the widely used cultural practice of crop rotation. This study analyzed the economic value of control options controlling the western CRW variant across Indiana. The options analyzed are soil insecticides, seed-applied insecticides, the recently commercialized genetically modified corn to resist CRW (CRW corn), or not controlling the western CRW variant. The results suggest that the economic value of CRW corn may exceed that of the alternative options for corn producers with high western CRW variant pressure, irrespective of producers' risk aversion levels and have the highest economic value for risk-averse producers in the moderate western CRW variant pressure region of Indiana.Crop Production/Industries,

Mean squared displacement and sinuosity of three-dimensional random search movements

Correlated random walks (CRW) have been used for a long time as a null model for animal's random search movement in two dimensions (2D). An increasing number of studies focus on animals' movement in three dimensions (3D), but the key properties of CRW, such as the way the mean squared displacement is related to the path length, are well known only in 1D and 2D. In this paper I derive such properties for 3D CRW, in a consistent way with the expression of these properties in 2D. This should allow 3D CRW to act as a null model when analyzing actual 3D movements similarly to what is done in 2DComment: 7 pages for main text, 2 pages for appendix, 1 figur

Estimating the Benefits of Bt Corn and Cost of Insect Resistance Management Ex Ante

This paper estimates farmer benefits for corn rootworm (CRW) active Bt corn and costs of complying with Environmental Protection Agency insect resistance management requirements. The estimates are obtained from farmer survey data that were collected in Minnesota in 2002, just prior to the commercial releases of CRW Bt corn. Benefit estimates range from $14 to$33.4 million, while compliance cost estimated range from $3.5 to$8.7 million depending on whether or not CRW Bt corn also controlled the European corn borer and whether of not it was approved for sale in major export markets.Bt corn, compliance costs, corn rootworm, insect resistance management, willingness to pay, Crop Production/Industries,

Influence of Date of Planting on Corn Hybrids with/without Bt Corn Rootworm Protection

Genetically-modified hybrids with corn rootworm (CRW) protection have been commercially available for six years. Hybrids with the Bt CRW traits are more expensive and initially were available in limited supply. Corn rootworm feeding pressure typically decreases on late planted/replanted corn. Producers were asking if the additional seed costs were justified and, if they could only get a limited supply of the Bt CRW hybrids, when should they be planted for maximum response. Marlin Rice, ISU Extension entomologist, conducted an initial 3-year study (2003–2005) in Central Iowa. The objective of this demonstration was to compare the corn root feeding damage, yield, and economic response of a Bt CRW hybrid with its non-Bt CRW isoline at three planting dates in a continuous corn rotation in Northern Iowa

Brief Announcement: Node Sampling Using Centrifugal Random Walks.

We propose distributed algorithms for sampling networks based on a new class of random walks that we call Centrifugal Random Walks (CRW). A CRW is a random walk that starts at a source and always moves away from it. We propose CRW algorithms for connected networks with arbitrary probability distributions, and for grids and networks with regular concentric connectivity with distance based distributions. All CRW sampling algorithms select a node with the exact probability distribution, do not need warm-up, and end in a number of hops bounded by the network diameter

FACTORS AFFECTING THE LIKELIHOOD OF CORN ROOTWORM BT SEED ADOPTION

The likelihood of adopting corn rootworm (CRW) Bt seed technology was analyzed using an ordered logit model. Data used to estimate the model came from USDAs 2001 Agricultural Resource Management Survey. Statistically significant variables include operator age, farm type, farm size, rootworm loss and current treatment for rootworm, off farm labor, and Bt technology for corn borer. The likelihood of adoption was not related to crop rotation, tillage system, new variant CRW region, or education.Crop Production/Industries,