Formulation of Microbial Herbicides

Greaves, M.P.; Holloway, Peter J.; Auld, B. A.

doi:10.1007/978-94-011-4926-6_6

Cited by 58 publications

(33 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In keeping with the conclusion of Boyette et al (2007) that water activity and temperature are the two most important environmental factors influencing mycoherbicide efficacy, the germination potential and mycelial growth of these two strains show a clear temperature optimum (near 25°C) and are negatively affected by low water activity (Dagno et al, 2010). Such influences make it important to consider with care the formulation of biocontrol agents, recognised as an important determinant of their efficacy (Greaves et al, 1998;Auld, 1993). Furthermore, having a cheap and locally available substrate on which to massproduce inocula can also be important (Siddiqui et al, 2008).…”

Section: Introductionmentioning

confidence: 72%

Production and oil-emulsion formulation of Cadophora malorum and Alternaria jacinthicola, two biocontrol agents against Water Hyacinth (Eichhornia crassipes)

Dagno¹,

Lahlali²,

Diourté³

et al. 2011

Afr. J. Microbiol. Res.

View full text Add to dashboard Cite

Cadophora malorum isolate Mln715 and Alternaria jacinthicola strain MUCL 53159 are under development as biocontrol agents against Water Hyacinth (Eichhornia crassipes) in Mali. Production of spores of these agents on locally available substrates (Water Hyacinth, powdered paddy rice chaff, wheat semolina) was assessed with a view to mass production. The C. malorum isolate sporulated best on Water Hyacinth (4.08 × 10 7 spores ml -1 ), followed by wheat (1.06 ×10 7 spores ml -1 ), whereas A. jacinthicola produced more spores on paddy rice chaff and wheat (0.24 x 10 7 spores ml -1 ). The severity of the damage caused by each pathogen was evaluated in the greenhouse and in the field. Under both greenhouse and field conditions, the biocontrol efficacy of the fungal isolates was improved with (unrefined) Carapa procera (L.) oil or (refined) palm oil, supplemented with soybean lecithin and Tween 20. When such a formulation was used, the incubation time was 4 to 5 days in the greenhouse and 7 to 9 days on the field, and the damage severity (DS) recorded 6 weeks after treatment varied from 87.02 to 93.13% in the greenhouse and from 59.11 to 63.00% in the field. For unformulated C. malorum and A. jacinthicola respectively, the incubation times were longer and the DS values were only 22.11 and 29.05% in the greenhouse and 12.05 and 15.15% on the field. Our results highlight good substrates for mass production of these mycoherbicides and demonstrate the ability of vegetable oil formulations to improve their efficacy.

show abstract

Section: Introductionmentioning

confidence: 72%

Production and oil-emulsion formulation of Cadophora malorum and Alternaria jacinthicola, two biocontrol agents against Water Hyacinth (Eichhornia crassipes)

Dagno¹,

Lahlali²,

Diourté³

et al. 2011

Afr. J. Microbiol. Res.

View full text Add to dashboard Cite

show abstract

“…The literature contains abundan t references to biologica l aspects of microbial herbicide development (TeBeest, 1991) and to formulation s designed to promote activity on the target weed (Greaves et al, 1998), though virtually no attention has been paid to application factors. It has been recognised for many years that spraying systems play a vital role in delivering and distributing herbicides for maximum eVect on their weed target.…”

Section: Discussionmentioning

confidence: 99%

Studies of Spray Application of Microbial Herbicides in Relation to Conidial Propagule Content of Spray Droplets and Retention on Target

Lawrie¹,

Greaves²,

Down³

et al. 2002

Biocontrol Science and Technology

View full text Add to dashboard Cite

This paper addresses the hypothesis that the spray applicatio n system used will aVect the retention of spray deposits of microbial herbicides on diVerent plant structures. There was greater spray retention on the hypocotyl of 4 to 6-true leaf Amaranthus retro¯exus plants (20-31%) sprayed with an aerosol-producin g laboratory sprayer than with a hydrauli c nozzle (3 -5%). Spray deposition and retention from the hydrauli c nozzle was increased by 28-42% when the nozzle was used horizontall y. Spray droplets generally contained the expected conidial number for the conidial concentration but this was aVected by increased inoculum density (size, concentration and mycelial contamination) , causing a reduction in the actual number of conidia present, compared to the expected. Up to 40 -50% of the conidia in the sprayed suspension could not be accounted for when conidium deposition was on a target. This loss could increase to 90 -92% when the weed was sprayed under a crop canopy.

show abstract

“…A signi® cant factor is the inconsistent performance of many once they are evaluated in the ® eld (Greaves et al, 1998). This is due largely to the environmenta l in¯uences, such 692 A. T. CHITTICK & B.…”

Section: Introductionmentioning

confidence: 99%

Polymers in Bioherbicide Formulation: Xanthium spinosum and Colletotrichum orbiculare as a Model System

Chittick¹,

Auld²

2001

Biocontrol Science and Technology

View full text Add to dashboard Cite

A requirement for extended periods of free water retention for fungal infection continues to limit the development of many potential bioherbicides. The use of hydrophili c polymers in the formulation of bioherbicides to overcome this limitation was investigated, using the potential bioherbicide Colletotrichum orbiculare and weed Xanthium spinosum as a model system. The relative humidity (RH) requirement of C. orbiculare required for adequate infection was > 95%. Water activity (a w ) required for growth of C. orbiculare was > 0.95 a w . A range of three natural and four artiWcial polymers, including gums and polyacrylamide s was tested. All polymers were found to be non-toxic to the fungal spores and thus suitable for use in bioherbicide formulations. Once incorporate d into the formulation, little improvement compared to the non-polyme r controls was observed on treated plants in the absence of dew. Water loss studies of the polymer suspensions were carried out at RHs of 33 and 75%. There were signiWcant diVerences between the polymers' ability to retain water, although some polymers retained up to a maximum of 36% water after 16 h at 75% RH; this was reduced to 3.2% at 33% RH. The a w of most polymers remained suYciently high for growth of C. orbiculare as water content decreased until it approache d zero. It was concluded that possible reasons for polymers not improving disease incidence might have been insuYcient volume of water retained, and/or fungal growth being obstructed by the structure of the polymers as water content and a w decreased.

show abstract

Formulation of Microbial Herbicides

Cited by 58 publications

References 80 publications

Production and oil-emulsion formulation of Cadophora malorum and Alternaria jacinthicola, two biocontrol agents against Water Hyacinth (Eichhornia crassipes)

Production and oil-emulsion formulation of Cadophora malorum and Alternaria jacinthicola, two biocontrol agents against Water Hyacinth (Eichhornia crassipes)

Studies of Spray Application of Microbial Herbicides in Relation to Conidial Propagule Content of Spray Droplets and Retention on Target

Polymers in Bioherbicide Formulation: Xanthium spinosum and Colletotrichum orbiculare as a Model System

Contact Info

Product

Resources

About