Pest management needs assessment for Oklahoma grain sorghum producers

              Division of Agricultural Sciences and Natural Resources • Oklahoma State University
EPP-7082
Oklahoma Cooperative Extension Fact Sheets
are also available on our website at:
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Oklahoma Cooperative Extension Service
Tanya C. Franke
Research Associate
Kathleen D. Kelsey, Ph.D.
Professor
Tom A. Royer, Ph.D.
Professor & IPM Coordinator
Acknowledgement
Funding for this guide was made available by the Oklahoma State University IPM Program.
Grain sorghum represents a significant row crop for Okla­homa growers. Grain sorghum (milo) is grown predominantly in north-central Oklahoma and the Oklahoma Panhandle. Acreage devoted to sorghum production has slightly declined during the past 10 years, averaging 462,000 acres planted from 1996 through 2000 to 354,000 acres planted from 2001 through 2005. Yields have remained steady averaging 46.8 bushels per acre from 1996 through 2005 (NASS, 2006). In 2006, producers harvested 270,000 acres of grain sorghum (NASS, 2008), which produced an average yield of 34 bushels per acre. The top five counties for grain sorghum production included Texas, Cimarron, Garfield, Alfalfa, and Kay (NASS 2008).
A self-administered mailed survey (Dillman, 2007) was developed by T. Franke and K. Kelsey in consultation with OCES faculty who had expertise in entomology, plant pathol­ogy, and plant and soil sciences. The objective of this survey was to identify pest management needs of Oklahoma grain sorghum producers to guide Oklahoma State University’s research and Extension programs in addressing their most critical needs. The survey asked Oklahoma grain sorghum producers to provide information about their production man­agement practices in regard to soil fertility, insects, and weeds. The population for the study consisted of 850 Oklahoma grain sorghum producers in 2006 and the sample consisted of a randomly stratified sample (n = 265). Eighty-nine (89) of the 265 surveys were returned (34 percent response rate). The 89 respondents planted 29,432 acres of grain sorghum in 2006 (average of 330 acres per producer), representing about 11 percent of the total grain sorghum grown. It should be noted that 2006 was a severe drought year, following several drought years, which may have affected the responses to the survey.
Findings
The issues identified by respondents that were of greatest concern with growing grain sorghum are listed in Table 1.
Pest Management Needs Assessment for Oklahoma Grain Sorghum Producers
Table 1. Top concerns with grain sorghum production identified by Oklahoma survey-respondents.*
High Moderate Low No
Issue Concern Concern Concern Concern
Weeds 65.6% 27.8% 5.6% 1.1%
Soil fertility 54.3% 40.2% 4.3% 1.1%
Harvest 49.4% 34.5% 12.6% 3.4%
Insects 38.5% 36.3% 24.2% 1.1%
Diseases 31.8% 31.8% 34.1% 2.3%
Bird damage 28.2% 34.1% 22.4% 15.3%
*Other concerns noted by producers (1 each) included: feed, yield (marked high concern), dry weather, discrimination vs. corn on feed value - discount price, and hog damage (marked low concern).
Weeds
Respondents (65.6 percent) identified weeds as the top issue with growing grain sorghum. They listed pigweed (f = 54) as the most frequent weed problem, followed by field bindweed (f = 34) as their top two weed problems (Table 2). Table 3 notes the herbicides used by respondents to treat weed problems in grain sorghum during 2006.
Table 2. Weeds encountered in grain sorghum by Okla­homa survey respondents.
Weeds Frequency (f)
Pigweeds 54
Field bindweed 34
Large crabgrass 28
Johnsongrass 28
Field sandbur 23
Common cocklebur 17
Barnyardgrass 13
Yellow foxtail 5
Shattercane 3
Musk-Canadian Thistle, Clammy
groundcherry, Walls Panicum,
Green Foxtail,
Panicum spp.,
Marestail,
Purslane,
Other 1 each