Weed Survey of Nova Scotia Lowbush Blueberry (Vaccinium Angustifolium Ait.) Fields

ABSTRACT

Weed surveys provide the basis for weed management research in lowbush blueberry, but have not been conducted in Nova Scotia since 2001. Documented declines in herbicide efficacy, loss and/or acquisition of herbicide active ingredients, confirmation of herbicide-resistant weed biotypes, and documented vectoring of weed seeds by machinery necessitate a new weed survey. A total of 165 bearing year lowbush blueberry fields were surveyed from 2017 to 2019, within which approximately 211 weed species were identified. Most weed species were herbaceous perennial forbs (89 species) and woody perennials (50 species), followed by annual broadleaf (24 species) and perennial grass weeds (20 species). The remaining flora consisted of a range of ferns, biennials, sedges and rushes, and orchids. The most common weed species were red sorrel (Rumex acetosella L.), poverty oatgrass (Danthonia spicata L. Beauv.), haircap moss (Polytrichum commune Hedw.), hair fescue (Festuca filiformis Pourr.), narrow-leaved goldenrod (Euthamia graminifolia (L) Nutt.), tickle grass (Agrostis hyemalis (Walter) BSP.), woolly panicum (Panicum lanugosum Ell.), cow wheat (Melampyrum lineare Desr.), bunchberry (Cornus canadensis L.), and yellow hawkweed (Hieracium caespitosum Dumort). Increased occurrence of these weed species is likely the result of documented or observed reductions in hexazinone and terbacil efficacy, confirmation of triazine-resistant biotypes, and common occurrence of seeds of these weed species on machinery. Low crop prices have also caused reduced pronamide use, contributing to increased occurrence of hair fescue. Results are guiding future research priorities for weed management in lowbush blueberry.

KEYWORDS:

• Weed survey
• vegetation survey
• lowbush blueberry
• wild blueberry
• vaccinium angustifolium Ait

Acknowledgments

Field assistance from Lienna Hoeg, Jianan Lin, and Peter Burgess is gratefully acknowledged. Cooperation of the many growers and field managers who assisted with field identification and location is also acknowledged.

Statement of conflicting interests

The authors state that there is no conflict of interest.

Supplementary materials

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This research was supported by a Natural Sciences and Engineering Research Council Collaborative Research and Development Grant (Grant # CRDPJ 500615-16) to S.N.W. in collaboration with the Wild Blueberry Producers Association of Nova Scotia;Natural Sciences and Engineering Research Council of Canada [CRDPJ 500615-16];