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United States Department of Agriculture

Agricultural Research Service

Research Project: Integrated Crop, Soil, and Water Management Systems for Sustainable Production of Sugarcane for Bioenergy Feedstock

Location: Sugarcane Research Unit

Title: Economics of supplemental weed control applications on spring-transplanted onions

Authors
item Taylor, Merritt -
item Webber, Charles
item Shrefler, James -

Submitted to: National Allium Research Conference
Publication Type: Proceedings
Publication Acceptance Date: January 23, 2013
Publication Date: July 11, 2013
Citation: Taylor, M.J., Webber III, C.L., Shrefler, J.W. 2013. Economics of supplemental weed control applications on spring-transplanted onions. 2012 National Allium Research Conference Proceedings, December 11-13, 2012, Las Cruces, New Mexico. p. 49-61.

Interpretive Summary: Field research was conducted in southeast Oklahoma to compare synthetic and organic herbicides for weed control in onions (Allium cepa L.). There were 21 treatments [12 synthetic herbicide treatments, 5 corn gluten meal (CGM) applications, a full-season weed-free (hand-weeded) treatment, a full-season weedy-check, a partial-season weed-free (weed-free for the first half of the growing season by hand weeding, then the weeds were allowed to grow), and a weedy-check without onions]. Data collected included weed control percentages, injury ratings, and yield by bulb size. The synthetic herbicides and CGM provided crop safety, and to some extent early weed control. However, reductions in crop yields and marketable bulb sizes as a result of weed competition demonstrated the need to include supplemental weed control with post-emergence herbicides or other weed control methods. An economic analysis was conducted to determine the impact of weed control methods on the net return to the producer. Within all 21 treatments, 10 treatments provided a positive net return. Of this group, only one of the weed-free treatments did not demonstrate a positive net return, although all treatments had considerable hand-weeding expenditures. This highlights the economic importance of weed pressures on onion yields, sizes and profitability. Eleven of the treatments had a negative net return. All of the CGM treatments had negative net returns due to the excessive cost of the CGM. Assuming that an acceptable return on the investment costs and risk factors of production is at the 15% level, data developed indicated that a complete or at least high level of weed control is justified for the farmer to have a high yielding harvest with large bulb sizes. The budget indicated that weed control expenditures which included both chemical control and hand weeding only comprised five percent of the total cost of production. If a field is expected to produce a high-yielding crop and the farmer observes an increase in weed pressure at an early stage of production, then the farmer should feel confident that the return on the expenditure for complete weed control above the planned expenditure can be justified with up to $3,898 increased cost per hectare.

Technical Abstract: Field research conducted to determine the relative benefits among alternative herbicides for weed control in onions (Allium cepa L.) measured weed control efficacy, impact of herbicides on crop injury, and the resulting weed competition on crop yields and marketable bulb size. Weed competition produced disproportionate reductions in total onion yields and size of marketable bulbs. There were 21 treatments [12 synthetic herbicide treatments, 5 corn gluten meal (CGM) applications, a full-season weed-free (hand-weeded) treatment, a full-season weedy-check, a partial-season weed-free (weed-free for the first half of the growing season by hand weeding, then the weeds were allowed to grow), and a weedy-check without onions]. The synthetic herbicides and CGM provided crop safety, and to some extent early weed control. However, reductions in crop yields and marketable bulb sizes as a result of weed competition demonstrated the need to include supplemental weed control with post-emergence herbicides or other weed control methods. Within all 21 treatments, 10 treatments provided a positive net return. Of this group, only one of the weed-free treatments did not demonstrate a positive net return, although all treatments had considerable hand-weeding expenditures. This highlights the economic importance of weed pressures on onion yields, sizes and profitability. Eleven of the treatments had a negative net return. All of the CGM treatments had negative net returns due to the excessive cost of the CGM. Assuming that an acceptable return on the investment costs and risk factors of production is at the 15% level, data developed indicated that a complete or at least high level of weed control is justified for the farmer to have a high yielding harvest with large bulb sizes. The budget indicated that weed control expenditures which included both chemical control and hand weeding only comprised five percent of the total cost of production. If a field is expected to produce a high-yielding crop and the farmer observes an increase in weed pressure at an early stage of production, then the farmer should feel confident that the return on the expenditure for complete weed control above the planned expenditure can be justified with up to $3,898 increased cost per hectare.

Last Modified: 11/26/2014
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