Curly Top Management. Carl Strausbaugh USDA-ARS NWISRL Kimberly, ID

Curly Top Management Carl Strausbaugh USDA-ARS NWISRL Kimberly, ID

Curly Top Symptoms

Severe Curly Top Symptoms

Vascular Discoloration Can Occur When Disease is Moderate to Severe Discolored Healthy

Beet Leafhopper - Vector

Beet Leafhopper Life Cycle Egg stage lasts 5.5 days at 100 F and 43.8 days at 60 F Nymphal stage 13 days at 95 F and 75.4 days at 65 F Development ceases below 55 F Brood development ranges between 1 and 2 months Likely to survive our most severe winters Ken Gray PNWPest.org Bennett, 1971

Beet Leafhopper Life Cycle Overwinters as adult female (carries virus) desert areas on mustard species Eggs laid in host leaves and stems 3 broods per year 1st brood in desert prior to spring migration Initial migration May 12 to June 5, avg. peak June 25 in southcentral Idaho 2nd and 3rd broods on sugar beet or other hosts Blickenstaff and Traveller, 1979

Acquisition of Beet curly top virus by the Beet Leafhopper Feeding time 1 min 2 min 5 min 30 min 1 hr 5 hr % of leafhoppers acquiring virus 1.4-3.3 6.7 26.5 28 44 76 Bennett & Wallace, 1938

Inoculation of Beet curly top virus by the Beet Leafhopper at 100 F Feeding time 1 min 2 min 3 min 10 min 20 min 30 min Plants infected (%) 1 7 22 34 52 68 Bennett & Wallace, 1938

Curly Top Nursery July 29, 2013

Correlation Between Disease Ratings for Curly Top Nursery and Nampa Commercials 2004 Nampa disease rating r 2 = 0.91 P < 0.0001 6 5.5 5 4.5 4 3.5 3 2.5 2 2.5 3 3.5 4 4.5 5 5.5 6 Nursery disease rating

Root Yield versus Disease Rating Nampa Commercials 2004 110 r 2 = 0.47 P < 0.0001 Root yield (t/ha) 100 90 80 2.5 3 3.5 4 4.5 5 5.5 6 Curly top rating

Idaho Curly Top Strain Survey 140 Total Severe Worland Cal/Logan Number of samples 120 100 80 60 40 20 0 2006 2007 2012 2013 2014

Curly Top at Nampa in 2005 Monohikari Untrt Check Poncho Beta

Poncho = 30.5 T/A Conv. = 21.5 T/A 9 T/A Advantage About 15 T/A Advantage in heavy CT portion of field Marvin Bay, Eaton, CO 2006

Seed/Foliar For Treatment Trial Non- treated check

2011 Curly Top Seed/Foliar Trt For B-45 on Sept 19 9 8 7 6 5 4 3 2 1 0 a bc bc Curly top rating 1 2 3 4 5 6 b Treatments c c Untreated check Scorpion Poncho Beta Poncho Beta + M & P NipsIt INSIDE Cruiser Force P > F <0.0001

2011 Curly Top Seed/Foliar Trt For Yield for B-45 Yield (t/a) 35 30 25 20 15 10 c ab ab b ab a 5 0 1 2 3 4 5 6 Treatments P > F <0.0001

16 Treatments on B-42 Untreated check Poncho, Poncho Beta, and Poncho Votivo Foliar products: Scorpion, Sivanto, Lorsban, Cyazypyr, Asana, and Mustang with and without Poncho Beta Hoppers 58-59 dap, foliars 6-7 days before hoppers and 6-8 days after

None Poncho Poncho Beta Poncho Votivo Scorpion PB + Scorpion Sivanto PB + Sivanto Lorsban PB + Lorsban Cyazypyr PB + Cyazypyr Asana PB + Asana Mustang PB + Mustang Curly top rating 7 6 5 4 3 2 1 0 Curly Top Rating For Sept 2013 * * * * * * * * * * * * P > F <0.0001; * = better than check PB = Poncho Beta

Curly Top Seed/Foliar Trts Sept 11, 2013 Mustang Poncho Beta Sivanto No seed trt

None Poncho Poncho Beta Poncho Votivo Scorpion PB + Scorpion Sivanto PB + Sivanto Lorsban PB + Lorsban Cyazypyr PB + Cyazypyr Asana PB + Asana Mustang PB + Mustang 60 50 40 30 20 10 0 Root Yield For 23 Sept 2013 a-d cd b-d fg ef b-d b-d a-c ab a de a-d de g g g P > F <0.0001 LSD = 4.01 PB = Poncho Beta Root yield (t/a)

None Poncho Poncho Beta Poncho Votivo Scorpion PB + Scorpion Sivanto PB + Sivanto Lorsban PB + Lorsban Cyazypyr PB + Cyazypyr Asana PB + Asana Mustang PB + Mustang 14000 12000 10000 8000 6000 4000 2000 0 Recoverable Sucrose For (lb/a) 9/23/13 * * * * * * * * * P > F <0.0001; * = not different PB = Poncho Beta

Conclusions Neonic seedtrts - early season curly top and pest control Curly top control for at least first 59 days Resistant cultivar seed and/or foliar trt help Pyrethroid foliar with last glyphosate application looks promising Resistance management

Research Goals Study 1 - Length of efficacy for neonic seed trts and pyrethroid sprays Study 1 - Will an out of area cultivar with little to no CT resistance stand up to late season pressure

Experimental Design 4 trts = untrt check, Poncho beta, Asana, and Poncho beta + Asana Series of 4 expts Out of Area Cultivar Expt 1 = CT 8 wk after planting (ap) &1 wk after foliar (af) Expt 2 = CT 9 wk ap & 2 wk af Expt 3 = CT 10 wk ap & 3 wk af Expt 4 = CT 11 wk ap & 4 wk af

Curly Top Rating Aug 2014 Curly top rating (0-9) Check Poncho Asana Poncho + Asana 7 6 5 4 3 2 1 0 a a b a b c b c b bc c c a b b b Wk 8 Wk 9 Wk 10 Wk 11 <0.0001 <0.0001 0.0002 0.0005

Curly Top Rating Sept 2014 Curly top rating (0-9) Check Poncho Asana Poncho + Asana 8 7 6 5 4 3 2 1 0 a a a b ab b bc b c c bc c Wk 8 Wk 9 Wk 10 Wk 11 <0.0001 <0.0001 0.0077 0.0678

Seed/Foliar Treatment Trial For Wk8 in Sept 2014 Poncho Beta + Asana Non- treated check

Root Yield (t/a) Root yield (t/a) 45 40 35 30 25 20 15 10 Check Poncho Asana Poncho + Asana 5 0 c ab b a d b c a b b Wk 8 Wk 9 Wk 10 Wk 11 <0.0001 <0.0001 <0.0001 0.0317 c a b a a ab

Estimated Recoverable Sucrose ERS (lb/a) 12000 10000 8000 6000 4000 2000 Check Poncho Asana Poncho + Asana a ab a b a b b b c c d c 0 Wk 8 Wk 9 Wk 10 Wk 11 <0.0001 <0.0001 <0.0001 0.0814

Conclusions Trend for less disease and more yield in checks over time Untrt check ranked as the worst trt regardless of week If CT is present even 77 days after planting, host resistance is important

Conclusions Seed trt had significant influence thru 70 days after planting Pyrethroids had a significant affect for 3 weeks based on yield variables The Poncho + Asana trt ranked the best during the first three weeks for all variables

Sucrose Reduction (%) in Storage For with Curly Top at Kimberly - Feb 25.0 20.0 15.0 10.0 5.0 Control Poncho Beta Control Poncho Beta 0.0 P > F < 0.05 2005 2006

Leafminer Damage on Sugarbeet For

Leafminer in 2010 on For B-45 on June 22 Infested plants (%) 80 60 40 20 0 a None b b b b b b Poncho Poncho M Poncho MP NipsIT NipsIT AV Cruiser P > F <0.0001

For Black Bean Aphid on Sugarbeet

For Black Bean Aphid Damage on Sugarbeet

Black Bean Aphid (% of plants with colonies) 20 15 Control Cruiser Tef Poncho Beta a a 10 5 0 Kim 21 Aug 2006 Declo 21 Aug 2008 P > F < 0.0001 b b b b (Planted Jun 12) (Planted Apr 16)

For Root Aphid on Sugarbeet

Root Aphid (% of plants with colonies on main root) 25 20 15 10 5 0 Control Cruiser Tef Poncho Beta a a No Data b b c Kim 4 Sep 2007 Declo 9 Sep 2008 P > F < 0.02

Seed Trts Poncho, Cruiser, NipsIt Will stand up to severe CT, but only a supplement to resistance CT = 17-20% yield inc. (6-7 tons/a) No CT = 5% yield inc. (2 tons/a) Early season control for leafminer and aphids; helps with rasping/chewing pests Resistance management Roots store better