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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #312672
Title: Meta-analysis of crop and weed growth responses to arbuscular-mycorrhizal fungi

Author
item LI, MENG - University Of Illinois
item JORDAN, NICHOLAS - University Of Minnesota
item KOIDE, ROGERT - Brigham Young University
item YANNARELL, ANTHONY - University Of Illinois
item Davis, Adam

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2016
Publication Date: 12/1/2016
Citation: Li, M., Jordan, N.R., Koide, R.T., Yannarell, A.C., Davis, A.S. 2016. Meta-analysis of crop and weed growth responses to arbuscular-mycorrhizal fungi. Weed Science. 64:642-652.

Interpretive Summary: Demand for non-chemical weed control tactics to support integrated weed management systems is growing, due to herbicide resistant weeds in conventional production systems and persistent weed problems in organic systems. Conservation biocontrol of weeds by managing soil microbial communities could potentially be very cost-effective, but requires more research to become useful. Arbuscular mycorrhizal fungi (AMF) have long been regarded as beneficial soil microorganisms, but have been reported to have detrimental effects on several non-mycorrhizal agricultural weed species. If AMF have negative effects on weeds but neutral or positive effects on crops under certain cropping system conditions, they could offer conservation biocontrol benefits against weeds. To quantify the effects of AMF infection on crops and agricultural weeds, we conducted a meta-analysis. Crops showed a significantly higher growth response to AMF than agricultural weeds. This contrasting effect of AMF on crops and weeds was more pronounced when phosphorus fertilizer was added, compared to those studies in which it was absent. Both C3 and C4 crops showed more positive responses than C3and C4 agricultural weeds. In addition, crops responded more positively than agricultural weeds when infected by mixed AMF communities, compared to single AMF species. Our results support previous claims that AMF may be managed to provide conservation biocontrol of agricultural weeds.

Technical Abstract: Arbuscular mycorrhizal fungi (AMF) have long been regarded as beneficial soil microorganisms, but have been reported to have detrimental effects on several non-mycorrhizal agricultural weed species. If AMF have negative effects on weeds but neutral or positive effects on crops under certain cropping system conditions, they could offer conservation biocontrol benefits against weeds. To quantify the effects of AMF infection on crops and agricultural weeds, we conducted a meta-analysis. Across all studies, the mean mycorrhizal growth response of plants increased by 30% when infected by AMF. Crops showed a significantly higher mean mycorrhizal growth response than agricultural weeds. This contrasting effect of AMF on crops and weeds was more pronounced when phosphorus fertilizer was added, compared to those studies in which it was absent. Both C3 and C4 crops showed more positive responses than C3and C4 agricultural weeds. In addition, crops responded more positively than agricultural weeds when infected by mixed AMF communities, compared to single AMF species. Our results of increased mycorrhizal growth of crops, in comparison to weeds, support previous claims that AMF may be managed to provide conservation biocontrol of agricultural weeds.