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The Concept and Application of Early Economic Period Threshold: The Case of DCPA in Onions (Allium Cepa)

Published online by Cambridge University Press:  12 June 2017

Claudio M. Dunan
Affiliation:
Dep. of Plant Pathol. and Weed Sci., Colorado State Univ., Fort Collins, CO 80523
Philip Westra
Affiliation:
Dep. of Plant Pathol. and Weed Sci, Colorado State Univ., Fort Collins, CO 80523
Edward E. Schweizer
Affiliation:
Agric. Res. Serv., U.S. Dep Agric., Colorado State Univ., Fort Collins, CO 80523
Donald W. Lybecker
Affiliation:
Dep Agric. and Res. Econ., Colorado State Univ., Fort Collins, CO 80523
Frank D. Moore III
Affiliation:
Dep. of Hortic., Colorado State Univ., Fort Collins, CO 80523

Abstract

The question of when to control weeds traditionally has been approached with the calculation of critical periods (CP) based on crop yields. The concept of economic critical period (ECP) and early (EEPT) and late (LEFT) economic period thresholds are presented as a comprehensive approach to answer the same question based on economic losses and costs of control. ECP is defined as the period when the benefit of controlling weeds is greater than its cost. EEPT and LEFT are the limits of the ECP and can be used to determine when first and last weed control measures should be performed. Calculation of EEPT accounts for the economic losses due to weed competition that occur between planting and postemergence weed control. In this way it is possible to better evaluate the economic feasibility of using preplant or preemergence control tactics. The EEPT for DCPA application is analyzed in the context of onion production in Colorado. The EEPT for DCPA application was calculated from an empirical regression model that assessed the impact of weed load and time of weed removal on onion yields. The EEPT was affected by control efficacy, weed-free yield, DCPA cost, and onion price. DCPA application was economically advisable in only one of 20 fields analyzed because of the tow DCPA efficacy (60%).

Type
Weed Management
Copyright
Copyright © 1995 by the Weed Science Society of America 

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References

LITERATURE CITED

1. Colorado Agricultural Statistics 1990. Colorado Agric. Statistics Serv., Lakewood, CO. p. 113.Google Scholar
2. Cousens, R. 1988. Misinterpretations of results in weed research through inappropriate use of statistics. Weed Res. 28:281289.Google Scholar
3. Cousens, R. 1991. Aspects of the design and interpretation of competition (interference) experiments. Weed Technol. 5:664673.Google Scholar
4. Dawson, J. H. 1986. The concept of period thresholds. Proc. Eur. Weed Res. Soc. Symp., Economic Weed Control. p. 327331.Google Scholar
5. Dunan, C. D. and Westra, P. 1991. Effects of weed competition on onion growth, yield, and quality. Proc. West. Soc. Weed Sci. 44:83.Google Scholar
6. Hall, M. R., Swanton, C. J., and Anderson, G. W. 1992. The critical period of weed control in grain corn (Zea mays). Weed Sci. 40:441447.CrossRefGoogle Scholar
7. Lybecker, D. L., Schweizer, E. E., and Westra, P. 1991. Computer-aided decisions for weed management in corn. West. J. Agr. Econ. 16:456.Google Scholar
8. Nieto, J. H., Brando, M. A., and Gonzales, J. T. 1968. Critical periods of the crop growth cycle for competition from weeds. Pest. Artic. News Summ. 14:159.Google Scholar
9. Roberts, H. A. and Ricketts, M. 1979. Quantitative relationships between the weed flora after cultivation and the seed population in the soil. Weed Res. 19:269275.Google Scholar
10. Zannin, Sattin M. G., and Berti, A. 1992. Case history for weed competition/population ecology: velvetleaf (Abutilon theoprasti) in corn (Zea mays). Weed Technol. 6:213219.Google Scholar
11. Westra, P. and Beck, K.G. 1992. Herbicide evaluations in Colorado. Pages 153154.Google Scholar
12. Zimdahl, R. L. 1988. The concept and application of the critical weed-free period. Pages 145155 in Altieri, M. A. and Liebman, M., eds. Weed Management in Agroecosystems: Ecological approaches, CRC Press, Boca Raton, FL.Google Scholar