Why are there no widely successful microbial bioherbicides for weed management in crops?

Abstract

Microbial biopesticides to control plant pathogens and insects in crops have had significant success. However, there have been relatively few successes for microbial bioherbicides in crops, despite considerable numbers of publications and commercial product introductions in this area. Marketed microbial bioherbicide products for use in agriculture have been largely unsuccessful. This article covers the potential advantages of successful microbial bioherbicides, as well as the biological and technical issues that have limited their success. Technologies to overcome the problems that have limited the success of these products are discussed. The many advantages of using killed microbial products (e.g. cell‐free filtrates) over living microbial products as bioherbicides are detailed. A commercialized mycoherbicide that has been selected for in the laboratory for control of the parasitic weed Striga hermonthica is being used with some success in Africa, indicating that non‐transgenic modification of the genetics of bioherbicide microbes for improved efficacy is acceptable to some regulatory authorities. Genetic modifications to improve efficacy and host range, as well as improved application technology to greatly reduce the amount of product needed are two technologies that are likely to expand the use of microbial bioherbicides in the future. © 2023 Society of Chemical Industry.

Transcriptome Analyses in Adult Olive Trees Indicate Acetaldehyde Release and Cyanide-Mediated Respiration Traits as Critical for Tolerance against Xylella fastidiosa and Suggest AOX Gene Family as Marker for Multiple-Resilience

“…Furthermore, microbiomes in general were suggested to contribute to metabolic stress relieve by buffering high amounts of carbon skeletons through carbon-consuming proliferation or secondary metabolism [ 40 ]. This view is not in contrast to the fact that increasingly isolated single components of microbiome structures can be successfully used to strengthen (or weaken, when applied as herbicides [ 71 , 72 , 73 , 74 ] plant fitness under various environmental conditions. Consequently, we hypothesized that transcript levels indicating higher carbon-consuming activities for the harbored fungal and/or bacterial communities as a whole, could mark the tolerant cultivar under Xf -infection.…”

The future of microbial bioherbicides

“…Sixteen of the articles in this issue are from conference participants. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Four related articles from non-participants are also included. [18][19][20][21] The article by Duke gives the rationale for the meeting, discussing the many microbial bioherbicides that have failed and detailing the technical and economic reasons for lack of success.…”

“…[18][19][20][21] The article by Duke gives the rationale for the meeting, discussing the many microbial bioherbicides that have failed and detailing the technical and economic reasons for lack of success. 2 He makes a case of the use of killed microbial preparations for weed control, as such products avoid many of the efficacy and safety issues of live organisms. Marrone provides an update on the status of the bioherbicide market and prospects for new bioherbicides.…”

“…The meeting was organized into twenty‐two 50‐min presentations with ample time for discussion. Sixteen of the articles in this issue are from conference participants 2–17 . Four related articles from non‐participants are also included 18–21 .…”

“…Four related articles from non‐participants are also included 18–21 . The article by Duke gives the rationale for the meeting, discussing the many microbial bioherbicides that have failed and detailing the technical and economic reasons for lack of success 2 . He makes a case of the use of killed microbial preparations for weed control, as such products avoid many of the efficacy and safety issues of live organisms.…”