Subscribe Now Subscribe Today
Fulltext PDF
Research Article
Microbial Herbicides for Weed Management: Prospects, Progress and Constraints

M. Chutia , J.J. Mahanta , N. Bhattacharyya , M. Bhuyan , P. Boruah and T.C. Sarma

Application of microbial herbicides for the management of agricultural weeds is an eco-friendly approach. A worldwide programme has been growing up to control the invasive weed species for the better crop production and stable ecosystem. Classical bio-control approach is not at all successful over the bio-herbicide approach. Although, a number of microbial herbicide has been developed to till date, only a few of them are available in commercial forms due to several constraints in the formulation, application and commercialization. Biocontrol agents probably fail to be marketed internationally as these are living organisms and are fearful to introduce them from foreign countries. Screening and genetic modification of potent microbial species are highly encouraged for a better commercial mycoherbicide development.

Related Articles in ASCI
Similar Articles in this Journal
Search in Google Scholar
View Citation
Report Citation

  How to cite this article:

M. Chutia , J.J. Mahanta , N. Bhattacharyya , M. Bhuyan , P. Boruah and T.C. Sarma , 2007. Microbial Herbicides for Weed Management: Prospects, Progress and Constraints . Plant Pathology Journal, 6: 210-218.

DOI: 10.3923/ppj.2007.210.218



Weeds cause serious ecological problems and are capable of altering the process of ecosystem, displacing the native flora and fauna. They may also support populations of non-native animals and microbes and hybridize with native species subsequently altering gene pools (Randall, 1996; Mahanta et al., 2007). Out of about 30,000 species widely distributed weeds, 1800 species cause yield loss by about 9.7% of total crop production every year in the world (Li et al., 2003). Weed can reduce crop yield by as much as 12%, which results to $32 billions in losses (Anonymous, 1998) as a whole. In 1980s, growers spent over $3 billions annually for chemical weed control, $2.6 billions for cultural, ecological and biological control method (Ross and Lembi, 1983). Non native weeds species are spreading and invading in United State wild life habitat at the rate of 7 lakhs ha/year (Babbitt, 1998), whereas 1 lakh ha/year in Europe, changing the basic structure of wetlands (Thompson et al., 1987). Weeds also serve as reservoir for plant pathogens that may cause significant economic loss in crop production. Besides these, weeds also cause environmental impact associated with its management such as non-target injury of living beings, contamination of ground and surface water etc. (Turnera et al., 2007). In this context, biological weed management practice seems to be a selective process against targeted weeds without damaging non-target living beings and environment.

Biological control is the deliberated use of living organism to control a pathogen or weed (Tamuli and Boruah, 2000; Hallett, 2005; Chutia et al., 2006). During last two decades biological weed control has received considerable attention. These has been results of the intensive use of chemical herbicides coming under scrutiny due to an increasing number of resistant or tolerant weeds (Heap, 1996), effect of non-target organisms, contamination of soil, ground water and food etc. Biological weed control practices have been developed for the sustainable use of biodiversity for economic benefit towards mankind. Insects have been used successfully in bio-control of weeds for many years (Wilson, 1964; Wasphera, 1982). The idea of using plant pathogens for management of weeds was reported before the turn of the century, but it is only in the last three decades that has received increasing interest (Charudattan, 1991; Watson, 1991; TeBeest, 1996).

Inoculative biological control and bioherbicide approach are the two steps in the microbial management of invasive weeds that have been applied successfully (Boyetchko and Rosskopf, 2006). Classical or inoculative biological control is the introduction of exotic organisms as a pathogen to the targeted weed species whereas, in bioherbicide approach microorganisms are multiplied artificially and applied to weeds in a manner similar to chemical herbicides (Mortensen, 1998).

Table 1: Classical approach of biological weed control practice under major projects


The bio-control approach using a pathogen imported from a foreign location to control a native or neutralized weed with minimal technological manipulations has been termed as classical or inoculative biological method. The overall success of classical biological control projects using imported pathogens has been estimated about 57% (Yandoc et al., 2006b) whereas, 30-35% in insect based weed bio-control projects. These success rates are calculated from the number of projects for which success can be verified from published accounts or reliable anecdotes compared to the number of known projects (Charudattan, 2005; Yandoc et al., 2006a).

A careful evaluation of efficacy and safety must precede a pathogens introduction, therefore valid protocols based on conceptual frameworks as well as empirical examples exist for selection of safe and effective agents (Watson and Wymore, 1990; Bickie and Morrison, 1993; Berner and Bruckart, 2005; Turnera et al., 2007). Precise identification of the race genotypes of the pathogens and confirmation of their virulence towards the target genotypes is important because the host pathogens specificity can be governed by single gene differences or by a small number of genes, particularly at the sub specific level (Yandoc et al., 2006a).

Classical bio-control of weeds began in 1960s on Rumex sp. in United States (Inman, 1971) and Rubus sp. in Chile (Oehrens, 1977). Since then lots of work has been done successfully (Table 1) in this programme (Bruckart and Hasan, 1991; Watson, 1991; Barton, 2005; Charudattan, 2005). Among the most successful is the control of Acacia salgina, Chondrilla juncea, Ageratina riparia, Carduus thoermeri, Cryptostegia grandiflora, Baccharis halimifolia, Mimisa pigra etc. by the different plant pathogen (Cullen, 1985; Trujillo et al., 1988; Baudoin et al., 1993; Bruckart et al., 1996; Luster et al., 1999; Morris et al., 1999). Uromycladium tepperianum was introduced as rust fungus for Acacia saligna, an invasive weed that threatens the Cap Fynbos Floristic Region of South Africa. This pathogen significantly decreased the tree density by 90-95%. The bio-control project to control C. juncea (rust skeleton) by Puccinia condrillina has been estimated to yield a cost of benefit ratio 1:100 to 1:200 (Cullen, 1985). Another successful weed bio-control programme has been achieved by the use of foliar smut fungus Cercosporella sp. in Hawaiian forest from Jamaica to control Ageratina riparia (Trujillo et al., 1988). It was estimated that more than 50,000 ha of pastureland have been rehabilitated to their full potential due to the application of this pathogens. No evidence of host resistance or the presence of mutant stains of the pathogens has been encountered (Trujillo, 1985, 2005). Puccinia jaceae var solstitialis is the recent introduction to the United States from Bulgaria and Turkey and the host range tests on these pathogens were extensive (Bruckart, 2006). A major project has been undertaken for biological management of Mimosa invisa, a non-native invasive species that threaten to the Kajiranga National Park in India. Several other projects have also been undertaken worldwide for the management of invasive species using microbes, insects, phytoextracts etc.


Microbial preparation of herbicide is defined as bioherbicides that can control the weed (Li et al., 2003). In this approach, indigenous plant pathogens isolated from weeds are cultured to produce the large numbers of infective propagules which are applied at a rate that will cause high levels of infection leading to suppression of the target weed. It is estimated that there are over 200 plant pathogens that have or are under evaluation for their potential as bio-herbicides; these include fungi and bacteria that cause foliar disease, soil born fungal and bacterial pathogens and deleterious rhizobacteria (DRB) (Rosskopf et al., 1999; Charudattan, 2001; Boyetchko et al., 2002). Sauerborn et al. (2007) described the virulence of parasitic weeds, their occurrence and parasitic life-style which make them suitable targets for biocontrol using the bioherbicidal approach-multiplication and periodic release of indigenous microbial agents for sustained control of the target species. A list of registered and commercially produced mycoherbicides are shown in Table 2. These plant pathogens based herbicide are generally evaluated for their virulence, performances under field condition, host range specificity etc.

Table 2: Status of microbial commercial bio-herbicide since 1964

Out of these hundreds of bio-herbicides a few of them are commercially available. Stumpout (Cylindrobasidium leave), EcoclearTM (Chondrostereum purpureum) and MycoTechTM paste are three commercially available bio herbicide (Barton, 2005). Smolder, a bio herbicide from Alterneria destruens has been registered recently and company planning to do more field trials and then market it in 2007. The others are unavailable due to the lack of continued commercial backing, high cost of mass production, introduction of newer herbicidal chemistries, resistant biotype (e.g., Dr. BioSedge) or limited markets. One herbicide agent, Collectrotrichum gloeosporioades f. sp. Aeschynomene has been reregistered (previously Collego) as of March 2006 under the commercial name LockDown for use in the rice in Arkansas, Lousianna and Mississippi (Yandoc et al., 2006b). All these herbicide have potential weed control capacity up to 100% in field condition though its efficacy regulated by inoculum’s concentration, formulation, spray parameters, target weed plant age, non-target plant species, micro and macro organisms in the phyllosphere or rhizosphere and pesticides applied in the area.

Many species of weeds were reported to acquire resistance against commercially available chemical herbicides. There are about 307 herbicide resistant weeds biotype worldwide, 113 of these biotypes occurs in the United States alone (Heap, 2006). Today it is possible to improve efficacy of plant pathogens by recombinant DNA technology. Charudattan and Dinoor (2000) has modified the host range to improve virulence of Xanthomonas campestries pv. Campestries (host Poa annua) by using gene encoding bialaphos production to control weed as some biotypes have developed resistance to a number of herbicide families. Loretta et al. (2006) described that 7 species of Amaranthus had become resistance to a number of herbicidal families. But the combined application of Phomopsis amaranthicola and Microsphaeropsis amaranthi as a mixture had significantly decreased the weed species in the field (100% mortality).


The formulation of bioherbicide is the blending of the active ingredient, the biological propagules with a carrier or solvent and often other adjuvant to produce a form which can be effectively delivered to the target weed (Boyette et al., 1991; Rhodes, 1993). Most of the formulations of the biological control agents are largely based upon techniques developed for formulation of agrochemical (Cook et al., 2005) involving the use of organic solvents, surfactants and drying methods, which can be detrimental to biological propagules (Connick et al., 1991).

Table 3: Formulating substrates /medium of potent bioherbicides

Majority of bioherbicide formulations are concentrated of maintaining agent viability in storage and reducing dew period requirements (Green et al., 1998). Liquid and solid formulations of bioherbicides are the two different approaches for infection in above and below ground parts of the weed species.

Liquid formulation: Liquid formulation includes aqueous, oil or polymer based products, oil suspension emulsion, inverted emulsion etc. tend to be used as post emergence sprays to incite leaf and stem diseases on the weed host (Boyette et al., 1991; Womack et al., 1996). Water is the simplest bio-herbicide delivery system contains the propagules of the agent formulated as spray able suspension in water (Connick et al., 1990). Application of adjuvant for bioherbicide formulation assists or modifies the action of a principal active ingredient (Foy, 1989). This encompasses a wide range of compounds (Table 3). A variety of microorganism produces some potent surfactants and can be used as bio surfactant in herbicide formulation (Laycok et al., 1991). Application of adjuvants in the formulation of herbicide sometimes cause up to 100% mortality of target weed within 48 hours (Winder and Watson, 1994). Yang and Jong (1995) prepared an inverted emulsion formulation of Myrothecium verrucaria by mixing and aqueous spore suspension with oil phase (1:1 v/v), where only oil emulsion carrier killed the 7 weed plants species. Auld (1993) developed an oil suspension emulsion formulation for control of Xanthium spinosum. Spores of Colletotrichum orbicularae were mixed with Kaolin (aluminium silicate powder) and dried. Dried powder (200 mg) was mixed with 20 mL of vegetable oils, 2 mL of an emulsifier and the water added to a volume of 200 mL. This formulation was tested in the field by Klein et al. (1995) and got up to 99% mortality in the first year. Two bioherbicides Collego and BioMal were commercially available as a wetable powder (Boyette et al., 1996). This formulation involves the drying of spores harvested from liquid fermentation, together with a carrier such as Kaolin which can be stored before suspension in water (Norman and Trujillo, 1995; Klein and Auld, 1996).

Solid formulation: Fungal pathogen infect weeds at or below the soil are best studied to solid of granular formulations (Connick, 1988; Boyette et al., 1991) which may consist of grains, peat, charcoal, clay, vermiculite, alginate, bagasse, mineral soil or filter mud as carrier (Green et al., 1998). These formulations of bio herbicides are better suited to pre emergence applications, attacking weed seedlings as they emerge from the soil (Connick, 1988). Since granular formulations contain dried propagules they may have a longer shelf life than liquid based formulations and is very important for a commercial bioherbicide (Auld, 1992).

During the last two decades, increasing interest has been observed on the synthetic beads of various materials for immobilization of herbicides, microorganism, cells and enzymes, antibodies, animal embryos and artificial seeds (Kierstan and Bucket, 1977; Barrett, 1978; Connick, 1982; Banerjee et al., 1984; Bashan, 1986; Cosby and Dukelow, 1990; Ling-Fong et al., 1993; Kremer et al., 2006). Biodegradable slow release beads comprised of sodium alginate and skim milk were developed as carriers for the bacterial inoculation of plants (Bashan, 1986). Walker (1981) developed a granular formulation of Alterneria macrospora for control of Anoda cristata. Mycellium of the pathogen was grown in liquid formulation, mixed with the horticultural vermiculite, exposed to diurnal light for 24 h to allow sporulation and air dried for 24-48 h. Field application of the granular inoculums incited almost 100% infection of A. cristata giving 75-95% control.


In spite of considerable research in bioherbicides, there are only two commercially available products in North America in 1996 (Mortensen, 1998) due to the constraints in bioherbicide development. Host variability and host range is the main biological constraints of bioherbicide development (Gabriel, 1991).

Table 4: Methods, advantage and constraints of controlling parasitic weeds (Sauerborn et al., 2007)

Sub-optimal temperature, moisture and compatibility with other pesticides are probably the most important environmental constraints for the efficacy of foliar bioherbicide (TeBeest, 1991; Kelly et al., 2006) in the field application. Formulation of a bioherbicide agent is one of the most challenging technological constrains to the development of reliable and efficacious product (Mortensen, 1998), as mass production of viable, infective and genetically stable propaguales of plant pathogens is a major requirement (Boyette et al., 1996). Sauerborn et al. (2007) described the major advantages and constraints of the parasitic agricultural weeds (Table 4). Due to these constraints several efficient bioherbicide agents have not been developed for commercial use by industries because of their low market potential and high cost of production (Charudattan, 1991; Templeton, 1992; Heap et al., 1993; Mortensen, 1996; Ghosheh, 2005).


With the development of sustainable agriculture and consciousness of human environmental protection government and enterprises will pay more attention to the study of exploitation of microbial pesticides because of their potential benefit for the environment (Li et al., 2003; Yandoc et al., 2004; Boyetchco and Rosskof, 2006). More than 27 exotic plant pathogens have been investigated for classical biocontrol of weeds and 67 weeds have been targeted using at least 107 fungal taxa as bioherbicide agents and 18 weed species have been targeted using deleterious rhizobacteria (Mortensen, 1998). From these literatures it can assume to be good potential of microbial weed control in future as the use of microbial herbicide will increase tremendously by 20% every year (Li et al., 2003, Turnera et al., 2007). It is necessary to overcome the constrains in this approach. New pesticide based on biosynthesis and molecular modification by gene technology would be the integrative steps for the exploitation of potential microbial herbicides.

Myrotheceium verrucaria was first evaluated for sickletod (Walker and Tilley, 1997) and kudzu control (Boyette et al., 2002) since, it has been evaluated for multiple targeted weeds. Multiple-Pathogen Strategy is a novel approach to increase the level of control of the targeted weed (Charudattan, 2001). Anderson and Hallett (2004) observed that culture filtrate from M. verrucaria had broad-spectrum activities across many plant families. Hallett (2005) points out that there are opportunities for the development of bioherbicides for some specialized niches, such as parasitic, urban and allergenic weed. Development of broad-spectrum bioherbicide not only for a particular species but also for a weed community of specific agricultural field or crop is highly demandable (Mahanta et al., 2007). Although most biological control agents are too host specific to individually address mixed weed population in agronomic field crops, they can be targeted to manage those weeds that have the maximum impact on crop yield in high valued crops where control options are limited.

Hoagland (1996) presented several approaches for improving biocontrol efficacy by disrupting the target weeds defense mechanism, including the use of herbicide or other compounds that affect key enzymes, blocking the synthesis of secondary plant metabolites or breaking down physical berries (Hodgson et al., 1988; Gressel et al., 2002; Peng and Byer, 2005; Hirase et al., 2006). Tiourebev et al. (2000) have attempted a novel approach to enhancing virulence of weed biological control agent by selecting for strains that capable of excreting high levels of amino acids that can suppress the growth and development of plants causing leaf distortion, loss of apical dominant and stunted growth. Development of multi-combination formulation and commercially available products of bioherbicide would be the potential approach for the successful weed management in future.

Anderson, K.I. and S.G. Hallett, 2004. Herbicidal spectrum and activity of Myrothecium verrucaria. Weed Sci., 52: 623-627.
CrossRef  |  Direct Link  |  

Anonymous, 1998. Statistical Abstract of the United States 1996. 200th Edn., US Bureau of Census, US Government Printing Office, Washington, DC.

Auld, B.A., 1992. Development and commercialization of biocontrol agents. Proceedings of the 1st International Weed Congress, February 17-21, 1992, AgMedia, Malbourne, Australia, pp: 269-272.

Auld, B.A., 1993. Vegetable oil suspension emulsion reduces dew dependence of a mycoherbicide. Crop Prot., 12: 477-479.

Babbitt, B., 1998. Statement by the secretary of interior on invasive alien species. Proceeding of the Nat. Weed Symp., BLM Weed Page. April 8-10, 1998.

Banerjee, M., A. Chakrabarthy and K. Majumder, 1984. Chrematistic of the yeast beta galactocidase immobilized in calcium alginates gels. Applied Microbiol. Biotecnol., 20: 271-274.

Barrett, P.R.F., 1978. Some studies of the use of alginates for the placement and controlled release of diquat on submerged aquatic plants. Pest. Sci., 9: 425-433.

Barton, J., 2005. Bioherbicides: All in a Days for a Superhero. Online. In: Whats New in Biological Control of Weeds? Manaaki Whenua Landcare Research, New Zealand Ltd., New Zealand, pp: 4-6.

Bashan, Y., 1986. Alginate beads as synthetic inoculants carriers for slow release of bacteria that affect plant growth. Applied Environ. Microbiol., 51: 1089-1098.

Baudoin, A.B.A.M., R.G. Abad, L.T. Kok and W.L. Bruckart, 1993. Field evaluation of Puccinia carduorum for biological control of musk thistle. Biol. Control, 3: 53-60.
Direct Link  |  

Berner, D.K. and W.L. Bruckart, 2005. A decision tree for evaluation of exotic plant pathogens for classical biological control of introduced invasive weeds. Biol. Control, 34: 222-232.

Bickie, H.J. and I.N. Morrison, 1993. Effect of ethalfluralin and other herbicides on trifluralin-resistant green foxtail (Setaria viridis). Weed Technol., 7: 6-14.

Boyetchko, S. and E.N. Rosskopf, 2006. Strategies for Developing Bioherbicides for Sustainable Weed Management. In: Handbook for Sustainable Weed Management, Singh, H.P., D.R. Batish and R.K. Kohli (Eds.), Haworth Press, Inc., New York, USA., pp: 393-420.

Boyetchko, S.M., E.N. Rosskopf, A.J. Caesar and R. Charudattan, 2002. Biological Weed Control with Pathogens: Search for Candidates to Applications. In: Applied Mycology and Biotechnology, Khachatourians, G.G. and D.K. Arora (Eds.), Elsevier Science, The Netherlands, pp: 239-274.

Boyette, C.D., G.E. Templeton and L.R. Oliver, 1984. Taxas gourd (Curcurbita texana) control with Fusarium solani f. sp. curcurbitae. Weed Sci., 32: 649-655.

Boyette, C.D., H.L. Walker and H.K. Abbas, 2002. Biological control of kudzu (Pueraria lobata) with an isolate of Myrothecium verrucaria. Biocontrol Sci. Technol., 12: 75-82.
Direct Link  |  

Boyette, C.D., P.C. Jr. Quimby, W.J. Jr. Connick, D.J. Daigle and F.E. Fulgham, 1991. Progress in the Production, Formulation and Application of Mycoherbicides. In: Microbial Crntrol of Weeds, TeBeest, D.O. (Ed.). Chapman Hall, New York, USA., pp: 209-222.

Boyette, C.D., P.C. Quimby Jr., A.J. Caesar, J.L. Birdsall and W.J. Connick Jr. et al., 1996. Adjuvants, formulations and spraying systems for improvement of mycoherbicides. Weed Technol., 10: 637-644.
Direct Link  |  

Bruckart, W.L. and S. Hasan, 1991. Options with Plant Pathogens Intended for Classical Control of Range and Pasture Weeds. In: Microbial Control of Weeds, TeBeest, D.O. (Ed.), Chapman and Hall, New York, USA., pp: 69-79.

Bruckart, W.L., 2006. Supplemental risk analysis of Puccinia jaceae var. solstitialis for biological control of yellow starthistle. Biol. Control, 37: 359-366.

Bruckart, W.L., D.J. Politis, G. Defago, S.S. Rosenthal and D.M. Supkoff, 1996. Susceptibility of Carduus, Cirsium and Cynara species artificially inoculated with Puccinia carduorum from musk thistle. Biol. Control, 6: 215-221.
CrossRef  |  Direct Link  |  

Charudattan, R. and A. Dinoor, 2000. Biological control of weeds using plant pathogens: Accomplishment and limitations. Crop Prot., 19: 691-695.

Charudattan, R., 1991. The Mycoherbicide Approach with Plant Pathogens. In: Chapman and Hall. Microbial Control of Weeds, TeBeest, D.O. (Ed.). University of Chicago Press, New York, ISBN: 0-412-01861-6, pp: 24-57.

Charudattan, R., 2001. Biological control of weeds by means of plant pathogens: Significance for integrated weed management in modern agro ecology. BioControl, 46: 229-260.

Charudattan, R., 2005. Ecological, practical and political inputs into selection of weed targets: What makes a good biological control target?. Biol. Control, 35: 183-196.

Chutia, M., J.J. Mahanta, R. Saikia, A.K.S. Boruah and T.C. Sarma, 2006. Effect of leaf blight disease on yield of oil and its constituents of Java Citronella and in vitro contro of the pathogen using essential oils. World J. Agric. Sci., 2: 319-321.

Connick, J.W.J., J.A. Lewis and P.C. Quimby Jr., 1990. Formulation of Biocontrol Agents for Use in Plant Pathology. In: New Directions in Biological Control: Alternatives for Suppressing Agricultural Pests and Diseases, Baker, R.R., P.E. Dunn and A.R. Liss (Eds.). Academic Press Inc., New York, pp: 345-372.

Connick, W.J. Jr., 1982. Controlled release of the herbicide 2,4-D and Dichlobenil from alginate gels. J. Applied Polymer. Sci., 27: 3341-3348.

Connick, W.J. Jr., 1988. Formulation of Living Biological Control Agents with Alginate. In: Pesticide Formulations, Innovation and Development, Cross, B. and H.B. Scher (Eds.). American Chemical Society, Washington DC., pp: 241-250.

Connick, W.J. Jr., C.D. Boyette and J.R. McAlpine, 1991. Formulations of mycoherbicides using a pesta like process. Biol. Control, 1: 281-287.

Cook, J., R. Charudattan, E.N. Rosskopf, T. Zimmerman, G. MacDonald and W. Stall, 2005. Integrated control of dodder (Cuscuta pentagona) using glyphosate, ammonium sulfate and the biological control agent Alternaria destruens. Proceedings of the Caribbean Food Crops Society Meeting, June 1, 2005, Caribbean Food Crops Society, pp: 6-8.

Cosby, N.C. and W.R. Dukelow, 1990. Microencaptulation of single, multiple and zone pellucida-free mouse preimplantation embryos in sodium alginate and their development in vitro. J. Report. Fretil., 90: 19-24.

Cullen, J.M., 1985. Bringing the cost benefit analysis of biological control of Chondrilla juncea up to date. Proceedings of the 6th International Symposium on Biological Control of Weeds, Vancouver, Canada, August 19-25, 1994, Agriculture Canada, Ottawa, pp: 145-152.

Egley, G.H. and C.D. Boyette, 1995. Water corn oil emulsion enhances conidia germination and mycoherbicidal activity of Colletotrichum truncatum. Weed Sci., 43: 312-317.
Direct Link  |  

Foy, C.L., 1989. Adjuvants: Terminology, Classification and Mode of Action. In: Adjuvants and Agrochemicals, Chow, P.N.P., C.A. Grant, A.M. Hinshalwood and E. Simundsson (Eds.), CRC Press, Boca Raton, FL., pp: 1-15.

Gabriel, D.W., 1991. Parasitism, Host Species Specificity and Gene Specific Host Cell Death. In: Microbial Control of Weed, TeBeest, D.O. (Ed.), Chapman Hall, New York, pp: 115-131.

Ghosheh, H.Z., 2005. Constraints in implementing biological weed control: A review. Weed Biol. Manage., 5: 83-92.

Green, S., S.M. Steward-Wade, G.J. Boland, M.P. Teshler and S.H. Liu, 1998. Formulation of Microorganisms for Biological Control of Weeds. In: Plant-Microbe Interactions and Biological Control, Boland, G.J. and L.D. Kuykendall (Eds.), Marcel Dekker, Inc., New York, pp: 249-281.

Gressel, J., D. Michaeli, V. Kampel, Z. Amsellem and A. Warshawsky, 2002. Ultralow calcium requirements of fungi facilitate use of calcium regulating agents to suppress host calcium-dependent defenses, synergizing infection by a mycoherbicide. J. Agric. Food Chem., 50: 6353-6360.

Hallett, S.G., 2005. Where are the bioherbicides?. Weed Sci., 53: 404-415.
CrossRef  |  Direct Link  |  

Hasan, S., 1972. Specificity and host specialization of Puccinia chondrillina. Ann. Applied Biol., 72: 257-263.

Hasan, S., 1988. Biocontrol of Weeds with Microbes, Biocontrol of Plant Diseases. CRC Press, Boca Raton, FL., pp: 129-151.

Heap, I.M., 1996. International survey of herbicide resistant weeds. Weed Sci. Soc., Am. Abstracts, 8: 9-9.

Heap, I.M., 2006. International survey of herbicide-resistant weeds. Weed Science Society of America and the Herbicide Action Committee.

Heap, I.M., B.G. Murray, H.A. Loeppky and I.N. Morrison, 1993. Resistance to aryloxypropionate and cyclohexanedione herbicides in wild oat (Avean fauta). Weed Sci., 41: 232-238.

Hirase, K., M. Nishida and T. Shinmi, 2006. Effect of δ-aminolevulinic acid on the herbicidal efficacy of foliar-applied MTB-951, a mycoherbicide to control Echinochloa crus-galli L. Weed Biol. Man., 6: 44-49.
CrossRef  |  Direct Link  |  

Hoagland, R.E., 1996. Chemical interactions with bioherbicides to improve efficacy. Weed Technol., 10: 651-674.

Hodgson, R.H., L.A. Wymore, A. Watson, R.H. Snyder and A. Collette, 1988. Efficacy of Colletotrichum coccodes and thidiazuron for velvetleaf (Abutilon theophrasti) control in soybean (Glycine max). Weed Technol., 2: 473-480.

Inman, R.E., 1971. A preliminary evaluation of Rumex rust as a biological control agent for curly dock. Phytopathology, 61: 102-107.

Kelly, N.B., P. Gary, M.W. Thomas and C.C. Brian, 2006. Spray retention and its effect on weed control by mycoherbicides. Biol. Control, 37: 307-313.

Kierstan, M. and C. Bucket, 1977. The immobilization of microbial cells, sub cellular organelles and enzymes in calcium alginate gels. Biotechnol. Bioeng., 19: 387-397.
Direct Link  |  

Klein, T.A. and B.A. Auld, 1996. Wounding can improve efficacy of Colletotrichum obiculare as a mycoherbicide for Bathurst burr. Aust. J. Exp. Agric., 36: 185-187.

Klein, T.A., B.A. Auld and W. Fang, 1995. Evaluation of oil suspension emulsions of Colletotrichum obiculare as a mycoherbicides for field trials. Crop Prot., 14: 193-196.

Kremer, R.J., A.J. Caesar and T. Souissi, 2006. Soilborne microorganisms of Euphorbia are potential biological control agents of the invasive weed leafy spurge. Applied Soil Ecol., 32: 27-37.
Direct Link  |  

Laycok, M.V., P.D. Hildebrand, P. Thibault, J.A. Walter and J.L.C. Wright, 1991. Viscosn, a potent peptidolipid biosurfactant and phytopathogenic mediator produced by a pectolytic strain of Pesudomonas flourescens. J. Agric. Food. Chem., 39: 483-489.

Li, Yongquan, Z. Sun, X. Zhuang, L. Xu, S. Chen and M. Li, 2003. Research progress on microbial herbicides. Crop Prot., 22: 247-252.
CrossRef  |  Direct Link  |  

Ling-Fong, T., K. Leng-Khim, L. Chiang-Shiong and E. Khor, 1993. Alginate chitosan coacervation in production of artificial seeds. Biotechnol. Bioeng., 42: 449-452.

Loretta, O.R., M. Martin and I.I. Williams, 2006. Conidial germination and germ tube elongation of Phomopsis amaranthicola and Microsphaeropsis amaranthi on leaf surfaces of seven Amaranthus species: Implications for biological control. Biol. Control, 38: 356-362.
Direct Link  |  

Luster, D.G., Y.T. Berthier, W.L. Bruckart and M.A. Hack, 1999. Post-release spread of musk thistle rust monitored from virginia to California using dna sequence information. Proceedings of the 10th International Symposium on Biological Control of Weeds, July 4-14, 1999, Montana State Univ., Bozeman, pp: 75-.

Mahanta, J.J., M. Chutia and T.C. Sarma, 2007. Study on weed flora and their influence on patchouli (Pogostemon cablin benth.) oil and patchoulol. J. Plant Sci., 2: 96-101.
CrossRef  |  Direct Link  |  

Morris, M.J., 1996. Impact of a gall forming rust fungus Uromycladium tepperianum on populations of an invasive tree, Acacia saligna in South Africa. Proceedings of the 9th International Symposium on Biological Control Weeds, Stellenbosch, South Africa, January 19-26, 1996, University of Capetown, SA., pp: 509-.

Morris, M.J., A.R. Wood and A. den Breeyen, 1999. Plant Pathogens and Biological Control of Weeds in South Africa: A Review of Projects and Progress During the Last Decade. In: African Entomology Memoir No. 1, Olckers, T. and M.P. Hill (Eds.) Entomological Society of South Africa, Hatfield, pp: 125-128.

Mortensen, K., 1996. Constraints and development and commercialization of a plant pathogen Colletrotrichum gloeosporioides f. sp. malvae for biological weed control. Proceedings of the 2nd International Weed Control Congress, Copenhagen, Denmark, June 25-28, 1996, Flakkebjerg, Denmark, pp: 1297-1300.

Mortensen, K., 1998. Biological Control of Weeds Using Microorganisms. In: Plant-Microbe Interactions and Biological Control, Boland, G.J. and L.D. Kuykendall (Eds.), Marcel Dekker, Inc., New York, pp: 223-248.

Norman, D.J. and B. Trujillo, 1995. Development of Colletotrichum gloeosporioides f. sp. clidemiae and Septori passiflorae into two mycoherbicides with extended viability. Plant Dis., 79: 1029-1032.

Oehrens, E., 1977. Biological control of blackberry through the introduction of the rust, Phragmidium violaceum, in Chile. FAO Plant Protect. Bull., 25: 26-28.

Peng, G. and K.N. Byer, 2005. Interactions of Pyricularia setariae with herbicides for control of green foxtail (Setaria viridis). Weed Technol., 19: 589-598.
CrossRef  |  Direct Link  |  

Politis, D.J., A.K. Watson and W.L. Bruckart, 1984. Susceptibility of Musk thistle and related composites to Puccinia carduorum. Phytopathology, 74: 687-691.

Prasad, V., 1994. Influence of several pesticides and adjuvants on Chondrostereum purpureum. A bioherbicide agent for control of forest weeds. Weed Technol., 8: 445-449.
Direct Link  |  

Randall, J.M., 1996. Weed control for the preservation of biological diversity. Weed Technol., 10: 370-383.

Rhodes, D.J., 1993. Formulation of Biological Control Agents. In: Exploitation of Microorganisms, Jones, D.G. (Ed.). Chapman and Hall, London, pp: 411-439.

Ross, M. and C. Lembi, 1983. Applied Weed Science. Burgess Publishing Company, Minneapolis, MN.

Rosskopf, E.N., R. Charudattan and J.B. Kadir, 1999. Use of Plant Pathogens in Weed Control. In: Handbook of Biological Control, Bellows, T.S. and T.W. Fisher, (Eds.), Academic Press, San Diego, CA., pp: 891-918.

Sauerborn, J., D. Muller-Stover and J. Hershenhorn, 2007. The role of biological control in managing parasitic weeds. Crop Prot., 26: 246-254.
CrossRef  |  Direct Link  |  

Tamuli, P. and P. Boruah, 2000. Biological control of Rhizoctinia solani Kuhn. In: Aromatic Cymbopogons by Trichoderma sp. Plant Arch., 2: 77-80.

TeBeest, D.O., 1991. Ecology and Epidemiology of Fungal Plant Pathogen Studied as Biological Control Agent of Weeds. In: Microbial Control of Weeds, TeBeest, D.O. (Ed.), Chapman Hall, New Work, pp: 97-114.

TeBeest, D.O., 1996. Biological Control of Weeds with Plant Pathogens and Microbial Pesticides. In: Advances in Agriculture, Sparks, D.L. (Ed.), Academic Press, Toronto, pp: 115-137.

Templeton, G.E., 1992. Use of Collectrotrichum Starins as Mycoherbicides. In: Colletrotrichum: Biology, Pathology and Control, Bailey, J.A. and M.J. Jeger, (Eds.), CAB International, Walloingford, Oxon, UK., pp: 358-380.

Thompson, D.Q., R.L. Stuckey and E.B. Thompson, 1987. Spread, impact and control of purple loosestrife (Lythrum salicaria) in North American wetlands. US. Fish and Wildlife Service Research Report 2.

Tiourebev, K.S., S. Nelson, N.K. Zidack, G.T. Kaleyva, A.L. Pilgeram, T.W. Anderson and D.C. Sands, 2000. Amino acid excretion enhances virulence of bioherbicides. Proceedings of the 10th International Symposium on Biological Control of Weeds, July 4-14, 1999, Montana State University, Bozeman, pp: 295-299.

Trujillo, E.E., 1985. Biological control of hamakua pa-makani with Cercosporella sp. in Hawaii. Proceedings of the 5th International Symposium on Biological Control of Weeds, Vancouver, Canada, August 19-25, 1984, Agriculture Canada, Ottawa, pp: 666-671.

Trujillo, E.E., 2005. History and success of plant pathogens for biological control of introduced weeds in Hawaii. Biol. Control, 33: 113-122.

Trujillo, E.E., M. Aragaki and R.A. Shoemaker, 1988. Infection, disease development and axenic culture of Entyloma compositarum, the cause of Hamakua pamakani blight in Hawaii. Plant Dis., 72: 355-357.

Turnera, R.J., G. Davies, H. Moore, A.C. Grundy and A. Mead, 2007. Organic weed management: A review of the current UK farmer perspective. Crop Prot., 26: 377-382.
CrossRef  |  Direct Link  |  

Walker, H.L. and A.M. Tilley, 1997. Evaluation of an Isolate of Myrothecium verrucariafrom sicklepod (Senna obtusifolia) as a potential mycoherbicide agent. Biol. Control, 10: 104-112.
CrossRef  |  Direct Link  |  

Walker, H.L., 1981. Granular formulation of Alternaria macrospora for control of spurred anoda (Anoda cristata). Weed Sci., 29: 342-345.

Wasphera, A.J., 1982. Biological Control of Weeds. In: Biology and Ecology of Weeds, Holzner, W. and M. Numata (Eds.), Junk Publishers, The Hague, pp: 47-56.

Watson, A.K. and L.A. Wymore, 1990. Biological control, a component of integrated weed management. Proceedings of the 7th International Symposium on Biological Control of Weeds, March 6-11, 1988, Rome, Italy, pp: 101-106.

Watson, A.K. and T. Alkhoury, 1981. Response of safflower cultivars to puccinia jaceae collected from diffuse knapweed in Eastern Europe. Proceedings of 5th International Symposium on Biological Control of Weeds, 1980, Brisbane, Australia, July 22-29, 1980, CSIRO, Malbourne, Australia, pp: 301-305.

Watson, A.K., 1991. The Classical Approach with Plant Pathogens. In: Microbial Control of Weeds, TeBeest, D.O. (Ed.), Chapman and Hall, New York, pp: 3-23.

Wilson, F., 1964. The biological control of weeds. Ann. Rev. Entomol., 9: 225-244.

Winder, R.S. and A.K. Watson, 1994. A potential microbial control of fire weed (Epiloboum angustifolium). Phytoprotection, 75: 19-33.

Womack, J.G., G.M. Eccleston and M.N. Burge, 1996. A vegetable oil based invert emulsion for microherbicides delivery. Biol. Control, 6: 23-28.

Yandoc, C.B., E.N. Rosskopf R.L. Pitelli and R. Charudattan, 2006. Effect of selected pesticides on conidial germination and mycelial growth of Dactylaria higginsii, a potential bioherbicide for purple nutsedge (Cyperus rotundus). Weed Technol., 20: 255-260.
CrossRef  |  Direct Link  |  

Yandoc, C.B., E.N. Rosskopf and R. Charudattan, 2006. Putting plant pathogens to work: Progress and possibilities in weed biocontrol. Part 2. Improving weed control efficacy. APS Net Plant Pathology. /weed1/.

Yandoc, C.B., J. Albano and E.N. Rosskopf, 2004. Effect of biopesticides, microbial inoculants and biorational products on Phytophthora nicotianae infection of periwinkle. Phytopathology, 94: S113-S113.

Yang, S.M. and S.C. Jong, 1995. Host range determination of Myrothecium verucari isolated from leafy spurge. Plant Dis., 79: 994-997.

Zimmermann, G., 1993. The entomopathogenic fungus Metarhizium anisopliae and its potential as a biocontrol agent. Pest. Sci., 37: 375-379.
CrossRef  |  

©  2019 Science Alert. All Rights Reserved
Fulltext PDF References Abstract