Submitted to: Journal of Sugar Beet Research
Publication Type: Abstract Only
Publication Acceptance Date: March 2, 2011
Publication Date: June 1, 2011
Citation: Strausbaugh, C.A., Eujayl, I.A., Wenninger, E. 2011. Neonicotinoid Seed Treatments and Foliar Sprays on Sugarbeet for Control of Severe Curly Top. Journal of Sugar Beet Research. 48(1&2):103. Technical Abstract: Sugarbeet production in semiarid regions is hindered by yield loss caused with Beet severe curly top virus and other closely related species vectored by the beet leafhopper. In 2010, a study was established to investigate the level of control from seed treatments and supplemental foliar insecticide sprays under severe curly top pressure, since previous testing was only under low to moderate pressure in Idaho. Two cultivars and 7 treatments were arranged in a randomized complete block design with 8 replications in 4 row plots planted on 3 May. The treatments included a non-treated check, NipsIt (60 g ai clothianidin/100,000 seed) with and without an experimental fungicide, Cruiser Force (60 g ai thiamethoxam + 8 g ai tefluthrin/100,000 seed), and Poncho Beta (60 g ai clothianidin + 8 g ai beta-cyfluthrin/100,000 seed). Poncho Beta was also tested with Movento (spirotetramat; 5 fl oz/A) or Movento + Provado (imidacloprid; 3.8 fl oz/A), which were applied twice (7 days before and again 5 days after inoculation). The plots were inoculated with 6 viruliferous beet leafhoppers per plant on 23 Jun at the 8-leaf growth stage. Plants in the center 2 rows were rated for curly top in Jul, Aug, and Sept and harvested on 6 Oct. The treatments reduced (P < 0.0001) curly top ratings by 32 to 43% in Jul, 36 to 60% in Aug, and 37 to 55% in Sept compared to the non-treated check, regardless of cultivar. Treatments yielded 26 to 31 tons/A across the two cultivars, which was significantly greater (P < 0.0001) than the non-treated check (1 to 3 tons/A). Yield among treated plots was not different, except Poncho Beta was better than Cruiser Force with Beta 4430R. All the neonicotinoid seed treatments looked promising for control of severe curly top pressure on sugarbeet but the foliar sprays made no difference for curly top control.