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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #186796
Title: NICKEL SUPPRESSES DAYLILY RUST, PUCCINIA HEMEROCALLIDIS ON SUSCEPTIBLE DAYLILIES, HEMEROCALLIS SPP. IN GREENHOUSE AND FIELD TRIALS

Author
item Reilly, Charles
item CRAWFORD, MARK - NIPAN, LLC, VALDOSTA, GA
item BUCK, J - UGA, GRIFFIN

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/2005
Publication Date: 6/15/2005
Citation: Reilly, C.C., Crawford, M., Buck, J.W. 2005. Nickel suppresses daylily rust, puccinia hemerocallidis on susceptible daylilies, hemerocallis spp. in greenhouse and field trials [abstract]. Phytopathology. 95(588).

Interpretive Summary: The recent discovery at the ARS Byron laboratory that nickel (Ni) salts reverse mouse ear disorder of pecan and river birch stimulated interest in its effect on disease suppression. Reports indicated that pathogens of several plant species, especially the rust fungi, were sensitive to Ni salts. Daylily rust, introduced into the U.S. in 2000 and spread widely from infected nursery stock, was selected as a model system to determine the role of Ni in disease suppression. Potted plants were sprayed with Ni at 50, 100, 200 or 400 ppm until runoff, then after 10 days, inoculated with the rust fungus. Ni reduced pustule formation by 90% at 200 ppm. Spores, applied to potato dextrose agar supplemented with Ni rates used to treat the daylily plants germinated normally. Germination was reduced slightly only at 400 ppm and phytotoxicity of plants was evident. In a second study, daylilies in outdoor beds were naturally infected with rust and treated with a commercial Ni nutrient supplement at 250 and 500 ppm or propiconazole. Plants were sprayed 3 times at 10 - 14 day intervals. After 30 days, untreated plants had rust pustules scattered throughout the canopy averaging 15% infection on new foliage while new foliage of plants treated with Ni or propiconazole where nearly free of rust pustules. Phytotoxicity was not observed in any of the treatments.

Technical Abstract: The recent discovery at the ARS Byron laboratory that nickel (Ni) salts reverse mouse ear disorder of pecan and river birch stimulated interest in its effect on disease suppression. Reports indicated that pathogens of several plant species, especially the rust fungi, were sensitive to Ni salts. Daylily rust, introduced into the U.S. in 2000 and spread widely from infected nursery stock, was selected as a model system to determine the role of Ni in disease suppression. Potted plants were sprayed with Ni at 50, 100, 200 or 400 ppm until runoff, then after 10 days, inoculated with the rust fungus. Ni reduced pustule formation by 90% at 200 ppm. Spores, applied to potato dextrose agar supplemented with Ni rates used to treat the daylily plants germinated normally. Germination was reduced slightly only at 400 ppm and phytotoxicity of plants was evident. In a second study, daylilies in outdoor beds were naturally infected with rust and treated with a commercial Ni nutrient supplement at 250 and 500 ppm or propiconazole. Plants were sprayed 3 times at 10 - 14 day intervals. After 30 days, untreated plants had rust pustules scattered throughout the canopy averaging 15% infection on new foliage while new foliage of plants treated with Ni or propiconazole where nearly free of rust pustules. Phytotoxicity was not observed in any of the treatments.