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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #321110
Title: Seed treatment with ethanol extract of Serratia marcescens is compatible with Trichoderma isolates for control of damping-off of cucumber caused by Pythium ultimum

Author
item Roberts, Daniel
item Lakshman, Dilip
item McKenna, Laurie
item Emche, Sarah
item Maul, Jude
item Bauchan, Gary

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2015
Publication Date: 3/1/2016
Citation: Roberts, D.P., Lakshman, D.K., Mckenna, L.F., Emche, S.E., Maul, J.E., Bauchan, G.R. 2016. Seed treatment with ethanol extract of Serratia marcescens is compatible with Trichoderma isolates for control of damping-off of cucumber caused by Pythium ultimum. Plant Disease. 100:1278-1287.

Interpretive Summary: Soilborne plant pathogens cause diseases that result in major economic losses to farmers in the United States. Biological control measures for these diseases need to be developed for conventional crop production systems due to environmental problems associated with existing chemical controls. We tested ethanol extracts of Serratia marcescens N4-5, when applied as a cucumber seed treatment, for control of damping-off of cucumber caused by Pythium ultimum in two soils. Plant stand associated with this treatment was similar to that of seeds treated with the chemical pesticide Thiram in a sandy loam soil but not in a loam soil. Ethanol extracts of N4-5 were compatible with two biological control fungi, not impacting colonization of cucumber by these fungi. Control of damping-off of cucumber was never diminished when these ethanol extracts were applied in combination with the biological control fungi and disease control was improved in certain instances with these combinations in the loam soil. Data presented here indicate that ethanol extracts of N4-5 are compatible with certain beneficial fungi suggesting that these extracts can be used as components of integrated disease control strategies featuring biological control fungi. This information will be useful to scientists devising strategies for control of soilborne plant pathogens.

Technical Abstract: Environmentally friendly control measures for soil-borne plant pathogens are needed that are effective in different soils when applied alone or as components of an integrated disease control strategy. Ethanol extracts of Serratia marcescens N4-5 when applied as a cucumber seed treatment effectively suppressed damping-off caused by Pythium ultimum in potting mix and in a sandy loam soil. Plant stand associated with this treatment was similar to that of seeds treated with the chemical pesticide Thiram in the sandy loam soil. These ethanol extracts did not consistently provide significant disease control in a loam soil. Ethanol extracts of N4-5 were compatible with two Trichoderma isolates, not impacting in vitro or in situ colonization of cucumber by these biological control fungi. ontrol of damping-off of cucumber was never diminished when these ethanol extracts were applied as a seed treatment in combination with in-furrow application of the Trichoderma isolates and disease control was improved in certain instances with these combinations in the loam soil.Data presented here indicate that ethanol extracts of N4-5 are compatible with certain beneficial fungi suggesting that these extracts can be used as components of integrated disease control strategies featuring biological control fungi.