|Chastagner, G - RESRCH & EXT CNT WASHINGT|
|Hummel, R - RESCH & EXT CNT WASHINGT|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2002
Publication Date: June 1, 2002
Citation: Copes, W.E., Chastagner, G.A., Hummel, R.L. 2002. Potential toxicity of chlorine and hydrogen dioxides on herbaceous and woody ornamental crops.Phytopathology. 92:S148. Technical Abstract: In a first step to developing spray strategies, chlorine dioxide (ClO(2)), at 0, 5, 50, 100, and 1,000 ppm, and hydrogen dioxide (H(2)O(2), Zerotol), at 0, 900, 2,700, 5,400, and 10,200 ppm, were sprayed 5 times at 3 day intervals on 8 bedding plant and 9 shrub species. Toxicity symptoms were rated using Horsfall-Barrett categories, with marketability being reduced if > 5 % surface area was affected. ClO(2) caused > 5 percent damage on no plants at 5, and 20 ppm; on poppy after 4 sprays at 50 ppm; on pansy after 3 sprays, on azalea, mountain laurel, and poppy after 4 sprays,and on a fern after 5 sprays at 100 ppm ClO(2); and on all plants, including coleus, evolvulus,galium, English ivy, juniper, lilac, rhododendron and St. Johns-wort at 1,000 ppm. H(2)O(2)caused > 5 percent damage on coleus after 4 sprays at 900 ppm, on rhododendron leaves and candytuft flowers after 5 sprays at 2,700 ppm; and on the same plants in fewer sprays at higher rates. Rates of ClO(2) and H(2)O(2) that should control pathogen propagules did not damage most plants tested.