1. Oklahoma State University Sorghum Headworm Sequential Sampling System Tom A. Royer Department of Entomology & Plant Pathology

2. Oklahoma State University Development of Headworm Sampling System Data on Economic and Treatment thresholds collected from Texas, Oklahoma, and Kansas (Elliott et al. 2012) Objectives:  Create a simple, dynamic, economically accurate sampling strategy for sorghum headworms  Develop an educational tool with information on headworm identification, and other sorghum pests.  Develop a flexible system that could be expanded as additional information became available and/or interface with real-time platform (such as I-Wheat).

3. Oklahoma State University The Product A computer program located at http://entoplp.okstate.edu/shwweb/index.htm http://entoplp.okstate.edu/shwweb/index.htm It has several elements: 1. Information on sorghum headworm 2. A calculator for determining economic thresholds for headworm infestations 3. Sequential sampling forms 4. Sampling instructions 5. Information on other sorghum pests

4. Oklahoma State University It allows a producer to play the “what If” game with pesticide costs, market values What Does the Headworm Decision Support System Provide?

5. Oklahoma State University It has a full complement of treatment threshold forms that can be printed off to serve as a permanent record of the sampling results What Does the Headworm Decision Support System Provide?

6. Assumptions: The Scout Needs to: Estimate sorghum plant populations Estimate composition of headworm sizes (Large, Medium, Mixed)  Mostly large headworms > ½ inch cause significant damage  Mostly medium headworms ¼ to ½ inches will also cause damage (less so, due to field mortality)  Small headworms < ¼ inches are not counted because many will die Oklahoma State University

8. What You Need to Know Plant Density  Number of sorghum heads per acre  Number of sorghum heads per length of row spacing  Pounds of seed planted per acre (assume that a pound of seed per acre results in 35,000 heads per acre  None of the Above (assume that 1 inch of rainfall results in 1100 heads per acre. Inches of rainfall is determined by clicking your location on the map.  (3 or 4 won’t give you as accurate an estimate ) Oklahoma State University

9. What You Need to Know Value of crop ($ per hundredweight) Control Cost ($ per acre) Oklahoma State University

10. What You Need to Know Directions 1. Walk 15-20 feet into field 2. Grasp and bend head into bucket and shake vigorously 3. Walk 30 paces in row to next sample, repeat 2 4. Walk 30 paces to next sample, repeat 2 (STOP 1) 5. Count medium ( 1 / 4 – ½ inches) and large > ½ inches) caterpillars, and determine whether most are Medium, Large or a Mixture (ca. 50/50). Sampling Technique Oklahoma State University

11. What You Need to Know Directions 1. Sample 3 more heads, combine count from first three heads with new count, mark total in box (STOP 2). Determine if you need to treat, not treat, or sample 3 more heads. 2. If you need to sample 3 more heads, move over 25 rows, and sample 3 heads. 3. Repeat 1 (STOP 3). 4. Repeat 1, and move over 25 rows AFTER you sample 6 heads in each row. Sampling Form Oklahoma State University

12. What You Need to Know Directions 1. If you sample at 16 stops and still can’t make a decision, return in 3 days and resample the field. Sampling Form Oklahoma State University

13. Data on time to decision. 10 fields, 16 stops, no decision made: 10 fields, no treatment after 3 stops, 9 samples Average time per stop: Average time: 19 minutes 37 seconds Average time: 3 minutes 4 seconds 1 minute 12 seconds Oklahoma State University

14. Next?. Oklahoma State University An Application for Smart Phone use in field.

15. Oklahoma State University Thanks!