Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-19T04:24:11.970Z Has data issue: false hasContentIssue false

Latent infections and residues of the bioherbicide agent Colletotrichum gloeosporioides f.sp. malvae

Published online by Cambridge University Press:  12 June 2017

Knud Mortensen
Affiliation:
Agriculture & Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK, Canada S7N 0X2

Abstract

Latent infections of Colletotrichum gloeosporioides f.sp. malvae (C. g. malvae) in plants and seed were determined in several crops under field conditions after application of C. g. malvae conidia at 12 times the recommended rate. Colletotrichum g. malvae was isolated in trace amounts from Brassica napus/campestris, Linum usitatissimum, Lens culinaris, Brassica juncea/hirta, Helianthus annuus, and Triticum spp. only at the 2-wk isolation. Colletotrichum g. malvae was never isolated from Beta vulgaris. After 5 wk, C. g. malvae was not detected in any of the crops, except for Carthamus tinctorius at harvest, and was not detected from wash water of plant tissue or seed after 72 h. Colletotrichum g. malvae recovery in the field, as in controlled environmental conditions, decreased with time, which indicates that buildup of inoculum did not occur. Fungi other than C. g. malvae and bacteria isolated from seed and from wash water of plant tissue increased with time throughout the growing season. Colletotrichum g. malvae was not recovered from seed or crowns of any of the crop cultivars at either location in either growing season, except for C. tinctorius. Only one seed of the C. tinctorius cultivar ‘S-208’ out of 17,280 C. tinctorius seed analyzed over three growing seasons tested positive for C. g. malvae. Colletotrichum g. malvae was found only on the seed coat; the germinated seedling was not infected. Colletotrichum g. malvae was not recovered from any of the wash water from seed. These results should alleviate any of the concerns regarding the fate of the millions of conidia applied during a normal spray operation on nontarget plants, the potential infectivity of nontarget plants, the potential buildup of C. g. malvae in the field, and the utilization of any of the C. g. malvae-treated crops for food or feed.

Type
Weed Management
Copyright
Copyright © 1999 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Present address: Wilmington College, 320 DuPont Highway, New Castle, DE 19720

References

Literature Cited

Agostini, J. P. and Timmer, L. W. 1992. Population dynamics and survival of Colletotrichum gloeosporioides, the cause of citrus postbloom fruit drop. Phytopathology 82:1084.CrossRefGoogle Scholar
Agriculture Canada. 1990. Guidelines for Registration of Naturally Occurring Microbial Pest Control Agents. Memorandum to registrants 90–03, August 1, 1990. Ottawa, Ontario, Canada: Agriculture Canada. 53 p.Google Scholar
Cerkauskas, R. F. 1988. Latent colonization by Colletotrichum spp.: epidemiological considerations and implications for mycoherbicides. Can. J. Plant Pathol. 10:297310.Google Scholar
Makowski, R.M.D. 1987. The Evaluation of Malva pusilla Sm. as a Weed and its Pathogen Colletotrichum gloeosporioides (Penz.) Sacc. f.sp. malvae as a Bioherbicide. Ph.D. dissertation. University of Saskatchewan-Saskatoon. 225 p.Google Scholar
Makowski, R.M.D. 1993. Effect of inoculum concentration, temperature, dew period, and plant growth stage on disease of round-leaved mallow and velvetleaf by Colletotrichum gloeosporioides f.sp. malvae . Phytopathology 83:12291234.Google Scholar
Makowski, R.M.D. 1995. Regulating microbial pest control agents in Canada: the first mycoherbicide. Pages 641648 in Delfosse, E. S. and Scott, R. R., eds. Proceedings of the VIII International Symposium on Biological Control of Weeds, February 2–7, 1992, Lincoln University, Canterbury, New Zealand. Melbourne: DSIR/CSIRO.Google Scholar
Makowski, R.M.D. and Mortensen, K. 1990. Colletotrichum gloeosporioides f.sp. malvae as a bioherbicide for round-leaved mallow (Malva pusilla): conditions for successful control in the field. Pages 513522 in Delfosse, E. S., ed. Proceedings of the VII International Symposium on Biological Control of Weeds, March 6–11, 1988, Rome, Italy. 1st. Sper. Patol. Veg. (MAF).Google Scholar
Makowski, R.M.D. and Mortensen, K. 1992. The first mycoherbicide Canada: Colletotrichum gloeosporioides f.sp. malvae for round-leaved mallow control. Pages 198300 in Proceedings of the First International Weed Control Congress, February 17–21, 1992. Melbourne: Monash University.Google Scholar
Makowski, R.M.D. and Mortensen, K. 1998. Latent infections and penetration of the bioherbicide agent Colletotrichum gloeosporioides f.sp. malvae on non-target field crops under controlled environmental conditions. Mycol. Res. 102:15451552.Google Scholar
Morin, L., Derby, J. L., and Kokko, E. G. 1996. Infection process of Colletotrichum gloeosporioides f.sp. malvae on Malvaceae weeds. Mycol. Res. 100:165172.CrossRefGoogle Scholar
Mortensen, K. 1988a. The potential of an endemic fungus Colletotrichum gloeosporioides, for biological control of round-leaved mallow (Malva pusilla) and velvetleaf (Abutilon theophrasti). Weed Sci. 36:473478.Google Scholar
Mortensen, K. 1988b. Report. Additional Host-Range Studies Conduct with Colletotrichum gloeosporioides f.sp. malvae Under Greenhouse Conditions. Regina, Canada: Agriculture and Agri-Food Canada. 9 p.Google Scholar
Mortensen, K. and Makowski, R.M.D. 1990. Field efficacy at different concentrations of Colletotrichum gloeosporioides f.sp. malvae as a bioherbicide for round-leaved mallow (Malva pusilla). Pages 523530 in Delfosse, E. S., ed. Proceedings of the VII International Symposium on Biological Control of Weeds, March 6–11, 1988, Rome, Italy. 1st. Sper. Patol. Veg. (MAF).Google Scholar
Mortensen, K. and Makowski, R.M.D. 1997. Effects of Colletotrichum gloeosporioides f.sp. malvae on plant development and biomass of non-target field crops under controlled and field conditions. Weed Res. 37:351360.Google Scholar
Templeton, G. E. 1975. EPA issues first experimental use permit for biological control fungus. Rice J. 78:2930.Google Scholar
Templeton, G. E., TeBeest, D. O., and Smith, R. J. Jr. 1984. Biological weed control in rice with a strain of Colletotrichum gloeosporioides (Penz.) Sacc. used as a mycoherbicide. Crop Prot. 3:409422.Google Scholar
Wei, Y. D., Byer, K. N., and Goodwin, P. H. 1997. Hemibiotrophic infection of round-leaved mallow by Colletotrichum gloeosporioides f.sp. malvae in relation to leaf senescence and reducing reagents. Mycol. Res. 101:357364.Google Scholar