Plant Pathology (2018) 67, 1296-1306

J.J. Dempsey, I. Wilson, P.T.N. Spencer-Phillips and D. Arnold (2018)
Suppression of the in vitro growth and development of Microdochium nivale by phosphite
Plant Pathology 67 (6), 1296-1306
Abstract: The ascomycete fungus Microdochium nivale is a major pathogen of many species of the gramineae. Control measures rely heavily on chemical fungicides, making alternative means of disease reduction desirable. Phosphite (PO₃^3-), has proven efficacy in reducing susceptibility of different species of gramineae to oomycetes, and has adverse effects on the in vitro growth of numerous other pathogens. The effect of phosphorous acid (H₃PO₃), phosphoric acid (H₃PO₄), dihydrogen potassium phosphite (KH₂PO₃), dihydrogen potassium phosphate (KH₂PO₄) and potassium hydroxide (KOH) on the in vitro mycelial growth and development of M. nivale was determined. Radial growth on amended potato dextrose agar (PDA) was used to calculate mean daily growth and percentage inhibition. PO₃^3- had a significant inhibitory effect on mycelial growth, with EC₅₀ values ranging between 35.9 and 40.99 μg mL^-1, whilst PO₄^3- and KOH had no significant inhibitory effect. Microscopic examination of mycelia showed morphological deformities in hyphae growing on PO₃^3- amended PDA, whilst hyphal growth was normal on PO₄^3- and KOH amended PDA. Conidial germination of M. nivale was significantly reduced following immersion in solutions of 50, 100 and 250 μg mL^-1 of PO₃^3-, while PO₄^3- and KOH at the same concentrations induced no inhibitory affect. These results show that PO₃^3- is a significant inhibitor of the growth of M. nivale and may have the potential to be used as a chemical control agent in the field.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Link to article at publishers website
Database assignments for author(s): Peter T.N. Spencer-Phillips

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Microdochium nivale