G. Chiasson1, G.L. Graham2 and É.
Thériault3
Parter: Bleuets NB
Blueberries
Abstract: A trial was initiated in the Lord and Foy region of New
Brunswick to evaluate the effect of varied nitrogen fertilizer application
rates on the growth and groundcover of lamb's-quarters (Chenopodium album L.)
within the sprout year of a wild blueberry field. This experiment was
established in an area which historically had problems with lamb's-quarters,
consequently a large natural seed-bank was expected. Five levels of nitrogen
fertility (0, 25, 50, 75 and 100 kg N/ha) were applied to 3m x 6m plots with
four replicates in the spring before crop and weed emergence. Visual estimates
of percent lamb's-quarter ground cover and average lamb's-quarters height were
recorded for each plot area. Nitrogen fertilizer had a significant effect on
the lamb's-quarters population, with an increasing population density for each
increase in nitrogen fertility. The addition of fertilizer also resulted in a
significant increase in the average lamb's-quarters height. All fertility
treatments resulted in significantly taller lamb's-quarters plants. This
finding confirms what has been observed in producer's fields where distinct
strips of lamb's-quarters were noted, coinciding with the overlapping of
fertilizer treatment. Flower bud number was significantly reduced by higher
fertility levels, with a significant yield decrease observed with for the 100
kg N/ha treatment as the majority of blueberry growth was vegetative in this
treatment. This research suggests that producers could potentially reduce
nitrogen fertility in areas prone to heavy lamb's-quarters infestations or
ensure the application of adequate herbicides to areas with high nitrogen
fertility. Expanded work on the link between fertility and weeds is required to
ensure producers are provided with information to enable them to utilize
fertilizer in the most sustainable manner.
1NB Department of Agriculture and Aquaculture, Regional Agri-Business Development, 1425 King Avenue Bathurst, New Brunswick E2A 1S7 2NB Department of Agriculture and Aquaculture, Crop Development Branch, P. O. Box 6000, Fredericton, NB E3B 5H1 3 NB Department of Agriculture and Aquaculture, Regional Agri-Business Development, P. O. Box 3058, Tracadie-Sheila, NB, E1X 1G5
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