Articles
Advances in powdery mildew and rust control for ornamental perennial crops
Article number
1435_34
Pages
257 – 264
Language
English
Abstract
Ornamental perennial crops are threatened by obligate fungal pathogens that cause unsightly disease and impact plant vigor.
The powdery mildew fungus (Golovinomyces (Syn. Erysiphe) cichoracearum DC.; Podosphaera sp.; Oidium sp.) forms a hyphal network across the leaves, flowers, and stems resulting in white, talcum-like colonies.
As the disease progresses, lower leaves drop, and the plant ceases to produce flowers, becoming unmarketable.
Powdery mildew is a common and destructive foliar disease of gerbera daisy (Gerbera jamesonii), dahlia (Dahlia hortensis), aster (Aster sp.), and phlox (Phlox paniculata). The rust pathogen, Puccinia malvacearum, infects hollyhock (Alcea rosea) and mallow (Malva sylvestris) causing light yellow-orange spots on the leaves which then progress to brown pustules; severe disease causes leaf death.
This study investigated plant protection products for their ability to limit these diseases under greenhouse or growth chamber conditions.
Floral crops known to be susceptible to powdery mildew or rust were inoculated by exposing them to naturally infected plants of the same type.
Plants were incubated under high relative humidity conditions.
Prior to inoculation, plant protection products were applied as a foliar spray using a hand-pump compressed-air sprayer and reapplied at specific intervals.
Assessment included the number of powdery mildew colonies or rust pustules and/or a disease severity rating.
Data were analyzed using SAS PROC GLM and statistical differences were compared using the FisherRSQUOs Protected Least Significant Differences or Student-Newman-Keuls test (P=0.05). Experimental trial results indicate that the following plant protection products effectively limited powdery mildew compared to the control: azoxystrobin + benzovindiflupyr, metconazole, myclobutanil, boscalid, trifloxystrobin, pyraclostrobin + boscalid, triflumizole, fludioxonil + cyprodinil, and azoxystrobin.
Effective products for rust protection included pyraclostrobin + boscalid, triticonazole + pyraclostrobin, mefentrifluconazole, and myclobutanil.
Successful management of powdery mildew and rust in ornamental perennial crops requires integration of this latest research with sanitation and environmental control strategies.
The powdery mildew fungus (Golovinomyces (Syn. Erysiphe) cichoracearum DC.; Podosphaera sp.; Oidium sp.) forms a hyphal network across the leaves, flowers, and stems resulting in white, talcum-like colonies.
As the disease progresses, lower leaves drop, and the plant ceases to produce flowers, becoming unmarketable.
Powdery mildew is a common and destructive foliar disease of gerbera daisy (Gerbera jamesonii), dahlia (Dahlia hortensis), aster (Aster sp.), and phlox (Phlox paniculata). The rust pathogen, Puccinia malvacearum, infects hollyhock (Alcea rosea) and mallow (Malva sylvestris) causing light yellow-orange spots on the leaves which then progress to brown pustules; severe disease causes leaf death.
This study investigated plant protection products for their ability to limit these diseases under greenhouse or growth chamber conditions.
Floral crops known to be susceptible to powdery mildew or rust were inoculated by exposing them to naturally infected plants of the same type.
Plants were incubated under high relative humidity conditions.
Prior to inoculation, plant protection products were applied as a foliar spray using a hand-pump compressed-air sprayer and reapplied at specific intervals.
Assessment included the number of powdery mildew colonies or rust pustules and/or a disease severity rating.
Data were analyzed using SAS PROC GLM and statistical differences were compared using the FisherRSQUOs Protected Least Significant Differences or Student-Newman-Keuls test (P=0.05). Experimental trial results indicate that the following plant protection products effectively limited powdery mildew compared to the control: azoxystrobin + benzovindiflupyr, metconazole, myclobutanil, boscalid, trifloxystrobin, pyraclostrobin + boscalid, triflumizole, fludioxonil + cyprodinil, and azoxystrobin.
Effective products for rust protection included pyraclostrobin + boscalid, triticonazole + pyraclostrobin, mefentrifluconazole, and myclobutanil.
Successful management of powdery mildew and rust in ornamental perennial crops requires integration of this latest research with sanitation and environmental control strategies.
Authors
M.K. Hausbeck, E.S. Tippett, C.M. Medina-Mora, C.L. Engfehr, B.R. Harlan
Keywords
herbaceous, fungicide, disease
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