Question 6: Sorghum IPM System for SCA Management G. David Buntin University of Georgia Sorghum – Sugarcane Aphid Research Exchange Meeting Dallas, TX January 3 – 4, 2017

Project 6: Sorghum IPM Systems for SCA Management Determine the effect of various IPM tactics in management systems on the populations and damage by sugarcane aphid in grain sorghum. Collaborator Name Affiliation Trial Location Plant Date Early Late David Buntin University of Georgia Griffin GA May 16, 2016 June 16, 2016 Ali Zarrabi, Tom Royer, Kris Giles Oklahoma State University Lane, OK May 5, 2016 June 20, 2016 Alana Jacobson Auburn University Shorter, AL June 10, 2016 June 30, 2016 M. O. Way Texas A&M University Beaumont, TX -- June 28, 2016

Introduction Planting date, early vs late Variety resistance/tolerance Insecticide seed treatment Poncho or Cruiser In-season foliar spray based on action threshold 1st: Sivanto prime @ 4 fl. oz./acre 2nd: Transform WG @ 1.5 oz/acre if needed

Materials & Methods Hybrid§ Poncho Seed Treatment Foliar spray regime GA OK TX AL 1 DKS 3888 (Sus) No √ 2 Yes -- 3 4 5 DKS 3707 (Res) 6 7 8 §In Alabama Pioneer 84P80 (Sus) and Pioneer 83P17 (Res); and Cruiser seed treatment Foliar Spray Regime: GA, OK, TX: AThreshold of 50 aphids per leaf; AL: AThreshold of 100 aphids per plant on 30% of plants; 2nd spray of Transform WG @ 1.0 fl. oz/A if needed. All trials sprayed for Fall Armyworms in whorl, Prevathon (GA, OK), Intrepid (AL)

Dates of first, peak and last SCA numbers in early and late plantings of sorghum in 4 state trials SUS = Susceptible, RES = Resistant, IST = Seed treatment Event-Treatment AL-Early AL-Late GA-Early GA-Late OK-Early OK-Late TX-Late 1st aphid 2 Aug§ 13 July 20 July 27 June 5 July 1 Aug Last date 30 Aug 25 Aug 24 Aug 31 Aug 16 Sep Peak SUS¶ 9 Aug 16 Aug 26 July 17 Aug 11 Aug Peak S-IST¶ Peak RES¶ 16-23 Aug 4 Aug -- Peak R-IST¶ Spray SUS 10 Aug 18 Aug 28 July 12 July 3 Aug. 12 Aug-14 Sep Spray S-IST None* 5 Aug 24 Aug-14 Sep Spray RES 12 Aug 19 July Spray R-IST *Aphids did not reach threshold level in this treatment and were not sprayed. §Dates approximate. ¶ Peak dates from No spray plots.

2016, Georgia SCA in early and late planting of susceptible (top) and resistant (bottom) sorghum with and without Poncho ST Resistance delayed Threshold, but not peak, by 1+ wk Susceptible (DKS 3888) Resistant (DKS 3707)

2016, Georgia, SCA on early and late planting of susceptible variety (DKS 3888) sorghum, no spray, with and without Poncho Insecticide Seed Treatment (Sdtrt) Seed treatment delayed Threshold by 1 week (TX, OK also) SCA peaked on sample date in both plantings. Insecticide seed treatment delayed SCA reaching threshold of 50 aphids per leaf by about 1 week in both planting.

Effect of SCA resistance, seed treatment and foliar spray on cumulative SCA aphid-days in early and late plantings in 3 state trials, 2016 Hybrid§ Seed Treat-ment Foliar Spray GA-Early GA-Late AL- Early AL- Late OK-Early OK- Late Susceptible No 4659a 4952a 25,422a 941c 6740a 7651a Yes 2847b 1428b -- 3346b 2023b 624c 939bc 9031b 887c 413c 259c 838c 405c 8378b 713c 167c 42c Resistant 1018c 292c 4411bc 2839c 660c 355c 456c 220c 4072bc 1091c 63c N/A 363c 145c 1766c 393c 14c Means in GA and OK within planting date followed by the same letter are not significantly different (LSD α=0.05). Means in AL followed by the same letter are not significantly different (LS means, α=0.05).

2016, Georgia, Effect of planting time, variety resistance, seed treatment and foliar spray for control of SCA on number of sorghum grain heads F = 0.72, P=0.6537ns F = 12.47, P <0.0001 Means within planting date followed by the same letter are not significantly different, LSD α=0.05

Effect of Poncho seed treatment on late-planted susceptible (DKS 3888) sorghum without foliar spray, 2016 Georgia Poncho Seed Treatment No Seed Treatment

Effect of Poncho seed treatment (right) on late-planted susceptible (DKS 3888) sorghum, No foliar spray, 2016 Texas

Effect of Poncho seed treatment (right) on late-planted Resistant (DKS 3707) sorghum, No foliar spray, 2016 Texas

2016,Texas, Effect of planting time, variety resistance, seed treatment and foliar spray for control of SCA on sorghum grain heads and yield Means within planting date followed by the same letter are not significantly different, LSD α=0.05 §Not included

2016, Georgia, Effect of planting time, variety resistance, seed treatment and foliar spray for control of SCA on sorghum grain yield F = 8.17, P <0.0001 F = 4.92, P <0.0020 Means within planting date followed by the same letter are not significantly different, LSD α=0.05

2016, Alabama, Effect of planting time, variety resistance, seed treatment and foliar spray for control of SCA on sorghum grain yield Not sprayed § § § F = 13.62; df=11, 33; P <0.0001 LS Means across both planting dates followed by the same letter are not significantly different, LSD α=0.05. §Not included

Sorghum IPM Systems for SCA Management in Oklahoma Grain Yield of Early and Late Plantings (Ali Zarrabi, Tom Royer, Kris Giles) Not sprayed Means with the same letter are not significantly different (LSD, α = 0.05). §Not included

Key Learnings SCA infestations about the same time regardless of planting date across the region. Planting date had variable effect later had lower yield potential. Later had more damage Variety tolerance/resistance delayed or prevent threshold infestations. Seed treatment effective in susceptible variety. Integration of variety tolerance / resistance, seed treatment and single foliar threshold spray effective in preventing damage.

Discussion