Skip to main content Accessibility help

Agronomic Practices for Growing Houndstongue (Cynoglossum officinale) as a Crop for Mass-Producing a Weed Biocontrol Agent

  • James R. Moyer (a1), Rosemarie A. DeClerck-Floate (a1), Brian H. Van Hezewijk (a1) and Louis J. Molnar (a1)


Houndstongue is a troublesome weed of pasture, rangeland, and open forest in British Columbia, Canada. Recently, a root-feeding weevil was released in Canada that successfully controls houndstongue patches, but it has been difficult to propagate this weevil in sufficient numbers for widespread release. The goal of the current study was to develop methods for growing houndstongue as a crop in a farm-field setting for weevil propagation. Field experiments were conducted to determine optimum seeding dates, depths, and rates for houndstongue. The effects of straw-residue cover and nitrogen-application rates were also examined. More than 90% of the seed used was viable, and about 50% of the planted seed emerged. The most consistent plant densities occurred when houndstongue was seeded in October and had a winter and early spring moist chilling period to break seed dormancy. For fall seeded houndstongue, plants emerged equally well from 2- and 5-cm depths. Houndstongue is moderately responsive to nitrogen fertilizer but usually did not benefit from additional straw cover on the soil before emergence. Houndstongue plants also survived in drought conditions. In conclusion, this weed can be consistently grown as a crop for the propagation of a root-feeding weevil for houndstongue control.


Corresponding author

Corresponding author's E-mail:


Hide All
Anonymous, , 1988. Soil Test Recommendations for Alberta: Technical Manual. Edmonton, AB, Canada Alberta Agriculture, Food and Rural Development. 49.
Anonymous, , 2004. Crop protection with chemicals. Agdex 606-1. Edmonton, AB, Canada Alberta Agriculture, Food and Rural Development. 508.
Boorman, L. A. and Fuller, R. M. 1984. The comparative ecology of two sand dune biennials: Lactuca virosa L. and Cynoglossum officinale L. New Phytol. 69:609629.
DeClerck-Floate, R. 1999. Impact of Erysiphe cynoglossi on the growth and reproduction of the rangeland weed Cynoglossum officinale . Biol. Control. 15:107112.
DeClerck-Floate, R., Moyer, J., Van Hezewijk, B., Smith, E., and Barbieri, J. 2006. Farming weeds and insects: exploring new methods for mass-producing weed biocontrol agents for houndstongue. Ottawa, ON, Canada Agriculture and Agri-Food Canada Final Report to the Cattle Industry Development Council of British Columbia. 35.
DeClerck-Floate, R. A. and Schwartzländer, M. 2002. Cynoglossum officinale (L.) houndstongue (Boraginaceae). Pages 337343. in Mason, P.G., Huber, J.T. eds. Biological Control Programmes in Canada, 1981–2000. Wallingford, UK CABI Publishing.
DeClerck-Floate, R. A., Wikeem, B., and Bourchier, R. S. 2005. Early establishment and dispersal of the weevil Mogulones cruciger (Coleoptera: Curculionidae) for biological control of houndstongue (Cynoglossum officinale) in British Columbia, Canada. Biocontrol Sci. Technol. 15:173190.
De Jong, T. J. and Klinkhamer, P. G. L. 1988. Seedling establishment of the biennials Cirsium vulgare and Cynoglossum officinale in a sand dune area: the importance of water for differential survival and growth. J. Ecol. 76:393402.
De Jong, T. J., Klinkhamer, P. G. L., and Boorman, L. A. 1990. Biological flora of the British Isles: Cynoglossum officinale L. J. Ecol. 63:335344.
De Jong, T. J., Klinkhamer, P. G. L., and Prins, A. H. 1986. Flowering behaviour of the monocarpic perennial Cynoglossum officinale L. New Phytol. 103:219229.
Dickerson, J. R. and Fay, P. K. 1982. Biology and control of hound's-tongue (Cynoglossum officinale). Proc. West. Soc. Weed Sci. 35:8385.
Freijsen, A. H. J., Troelstra, S. R., and Van Kats, M. J. 1980. The effect of soil nitrate on the germination of Cynoglossum officinale L. (Boraginaceae), and its ecological significance. Oecologia Plant. 1:7179.
Knight, A. P., Kimberling, C. V., Stermitz, F. R., and Roby, M. R. 1984. Cynoglossum officinale (hound's-tongue)—a cause of pyrrolizidine alkaloid poisoning in horses. J. Am. Vet. Med. Assoc. 184:647650.
Moyer, J. R., Blackshaw, R. E., Smith, E. G., and McGinn, S. M. 1997. Summer Fallow Weed Control with Short-Term Cover Crops. Edmonton, AB Final Report to Alberta Agricultural Research Institute Project 920102. 103.
Moyer, J. R., Nitschelm, J., Regitnig, P., Blackshaw, R. E., Huang, H. C., and Chang, C. 2004. Effect of tillage system and crop sequence on irrigated sugarbeet production. Can. J. Plant Sci. 84:739747.
Prins, A. H., Nell, H. W., and Klinkhamer, P. G. L. 1992. Size-dependent root herbivory on Cynoglossum officinale . Oikos. 65:409413.
Roberts, H. A. and Boddrell, J. E. 1984. Seed survival and seasonal emergence of seedlings of some ruderal plants. J. Appl. Ecol. 21:617628.
Schwarzlaender, M. 1997. Bionomics of Mogulones cruciger (Coleoptera: Curculionidae), a below-ground herbivore for the biological control of hound's-tongue. Environ. Entomol. 26:357365.
Teasdale, J. R. and Mohler, C. L. 1993. Light transmission, soil temperature, and soil moisture under residue of hairy vetch and rye. Agron. J. 85:673680.
Upadhyaya, M. K. and Cranston, R. S. 1991. Distribution, biology, and control of houndstongue in British Columbia. Rangelands. 13:103106.
Upadhyaya, M. K., Tilsner, H. R., and Pitt, M. D. 1988. The biology of Canadian weeds, 87: Cynoglossum officinale L. Can. J. Plant Sci. 68:763774.
Van Breeman, A. M. M. 1984. Comparative germination ecology of three short-lived monocarpic Boraginaceae. Acta Bot. Neerl. 33:283305.
Van Hezewijk, B. and DeClerck-Floate, R. 2005. Soil fertility affects the preference and performance of weed biocontrol insect. Pages 37. in. Proceedings of the Joint Annual Meeting of the Entomological Society of Canada and the Entomological Society of Alberta. Ottawa, ON, Canada Entomological Society of Canada.
Van Leeuwen, B. H. and Van Breemen, A. M. M. 1980. Similarities and differences in some biennials. Acta Bot. Neerl. 29:209210.
Wagner-Riddle, C., Gillespie, T. J., and Swanton, C. J. 1994. Rye cover crop management impact on soil water. Can. J. Plant Sci. 74:486495.


Agronomic Practices for Growing Houndstongue (Cynoglossum officinale) as a Crop for Mass-Producing a Weed Biocontrol Agent

  • James R. Moyer (a1), Rosemarie A. DeClerck-Floate (a1), Brian H. Van Hezewijk (a1) and Louis J. Molnar (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed