Wild Blueberry Newsletter – August 2015

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August 2015

Wild Blueberry Crop Prospects 2015

Maine David Yarborough, University of Maine

The blueberry plants in Maine had a long fall but the onset of winter occurred rapidly and many plants may not have hardened off well. We also had an extremely cold winter but with good snow cover that extended into March, so plants were delayed in their development and pollination occurred later than normal.  We did observe some winter injury, especially in areas that had the snow cover blown off. There were only a few scattered frosts, so very little damage occurred from this.  Despite the delay in growth we had a large bloom so there were plenty of blossoms, providing the potential for a large crop.  The mid-coast Union area had excellent weather conditions and an exceptionally high fruit set but the Downeast fields were delayed with much cooler and windier weather that prevented a large fruit set, but most fields that had adequate bees had an average fruit set. We had a fairly dry May so we had few infection periods for mummyberry disease. There was some Botrytis blossom blight observed this year because of the wet conditions during bloom in the Downeast fields. Tony Jadzack’s estimate for bees contracted to pollinate wild blueberries was 77,000 hives, which is a little less than last year.  In Jonesboro, we received 3.54, 1.32, 6.52, 2.15 and 1.12 inches of rain in April, May, June and July and August, respectively. May was dry, precipitation in July and August has been well below the one inch a week needed for good growth and production.  The cooler temperatures over the summer provided for excellent blueberry fruit quality but the poor pollination and lack of moisture resulted in a smaller fruit size. Many fields had winter injury so crop yields are variable from field to field. Crop progress was delayed Downeast and harvest started late. The crop in Maine is now estimated to be less than average at 80 to 85 million pounds.

Quebec Pierre-Olivier Martel, Quebec Agriculture Ministry

In Quebec, cold temperature arrived quickly last December after a warm weather and rain episode. In many production areas, plants did not harden off well. We also had a low snow cover and very cold temperatures. In the spring, we observed a lot of winter frost and a lot of variability in bloom. We observed damage between 10 to 90% in many fields. Hopefully, weather during pollination was good and hives strong; we did not see any frost. We didn’t have much disease either, except for mummyberry in some fields. A few fields were treated for flea beetle in prune fields, but little activity for this insect. It is dry in many production areas, but the rain forecast for this week may change the picture. The crop in Quebec could be about 30 to 40 million pounds. The winter injury is principally responsible for the yield reduction.

Nova Scotia – Peter Burgess, Perennia

Nova Scotia had a cold winter and a delayed start to the growing season due to the high volume of snow.  By early May, crop development was delayed by almost two weeks through the province.  Some winter damage is evident but it is relatively minor and only in areas where snow was blown off fields. It was an unusually dry May so Monilinia infections were very low, with just minor damage seen. June was damp and cool with some Botrytis pressure noted.   There were two separate frost events in mid bloom with very little effect on the crop. Nova Scotia again brought in 5000+ hives from Ontario and western Canada through the import permit program.  Domestically Nova Scotia had low winter honey bee losses, and over 20,000 of those hives were used for pollination.  The use of Bumble bee quads is continuing to increase as well. There were lots of native pollinators again throughout the province. The weather during bloom was not ideal but there were adequate flying days to allow for pollination. Nova Scotia looks to have a good to very good fruit set, however yields should be less than last year’s record crop. That being said, the provincial yield should still be above the 5-year average of 40.6 million pounds.

New Brunswick- Michel Melanson, NB Department of Agriculture, Aquaculture and Fisheries

Minimal winter injury has been observed in many fields.  Fruit bud scale separation was visible during the second week of May, similar to last year, but later than previous years.  The snow melt was late this spring, delaying field operations.  Monilinia blight infection periods occurred, but levels were generally low.  Wet periods occurred during bloom; however, minimal infection of botrytis blight was present, likely due to pre-bloom fungicide applications. There were a couple of cold nights during bloom but temperatures recorded at the weather station were never below freezing.  Only a few flowers were open at this time therefore, low lying areas may have been at risk and some frost injury was noted. Bloom was generally good and weather was cool and wet, however, over the period, there was still good pollinating days.  An estimated 35,000 colonies were used for pollination in wild blueberry fields, slightly higher than last year.  Bumble bees and Alfalfa leafcutter bees use was also higher in 2015 compared to 2014.  In southwestern NB, 2.6 and 10.1 inches of rain in May and June respectively were recorded.  Crop is still in early fruit set, and difficult to assess at this time.  Crop stage is similar to last year but later than the previous years (2012 and 2013).  With the recent warmer temperatures, crop development could catch up quickly.  If normal rainfall occurs during the month of July and early August, the crop in NB should be average.  The provincial 5-year average is 42.5 million pounds, but with newly developed fields maturing and improving production practice, a crop of 50 million pounds could be expected, not as good as last year’s crop of 60.3 million pounds.

Prince Edward Island Chris Jordan, PEI Department of Agriculture & Fisheries

PEI experienced a cold fall in 2014 with no significant snow fall until mid-January. The province received record breaking snow accumulation during the winter and fields remained covered until early May in several regions. Very little winter injury resulted. Most fields were covered with two fungicide sprays for Monilinia and control appeared to be good. Pollination season was at least one week later than normal and there was lots of bloom present on the fields. Pollination weather was good with two minor frost events occurring during June. PEI had 11,500 colonies available for pollination. This is a record number for PEI with the majority being supplied by resident beekeepers and a significant number imported from Ontario. Bumblebee quads continue to be a popular add-on to complement native bees and honey bees. Fields need rain to help berries size up over the next several weeks. Final crop estimate is expected to reach 20 million pounds in 2015. Five-year running average crop for PEI is 15 million pounds with a record crop harvested in 2014 at 22.7 million pounds.

5-Year Wild Blueberry Yield for Maine and the Canadian Provinces


David E. Yarborough
Extension Blueberry Specialist

Wild blueberry fact sheets, past newsletters, contacts, resource links, calendar of events, and more can be found at the wild blueberry website: www.wildblueberries.maine.edu

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© 2015

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