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Wild
Blueberry Newsletter |
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August 2007 WILD BLUEBERRY CROP PROSPECTS Maine - The crop in Maine should be an average one this year. We had a wet fall and a mild winter, but winter injury was seen in some fields, in up to 30% of the stems, which eliminated any possibility of a large crop. The dry weather during pollination increased the potential crop and reduced any loss from mummy berry disease and from blossom blight disease, which was not observed this year in the fields. We did have numerous outbreaks of flea beetle which devastated individual fields, if they were not detected and treated in a timely manner. For precipitation at Blueberry Hill Farm, in April we had 16.4 inches (with about 10 inches coming in one storm at the beginning of April), in May we had 3.93 inches, in June we had little precipitation - 2.75 inches and in July we had only 3.3 inches. Despite all of the furor over the bee decline, bees were available if you were willing to pay the higher price. We had 65,050 honeybee hives brought into the state for pollination, and the weather was conducive for good pollination. Earlier the cool temperatures delayed development and the lack of moisture has resulted in smaller size fruit. Although the temperatures have increased the lack of moisture will reduce the crop. A survey of wild blueberry growers conducted by the New England Agricultural Statistics Service in New Hampshire estimated the Maine 2007 crop to be 66 million pounds, which is just above the five-year average of 64.3 million pounds. You may view this report on the web at: http://www.nass.usda.gov/Statistics_by_State/New_England/index.asp under Publications and Releases and then Special Reports - Maine Wild Blueberries - July 31, 2007. Nova Scotia – Weed problems continue, and last year had considerable leaf diseases, especially Septoria leaf spot and rust infection. Fruit bud numbers were reduced last year and some of these fruit buds were under-developed resulting in higher winter kill and lower flower numbers and subsequent fruit set. Rainfall has been good, and the crop may be slightly better than last year because of the better pollinating weather. The estimate is for a 32 to 34 million pound crop. Quebec – The crop is expected to be less than last year because of winter kill and frost during bloom. Quebec has had a lot of rain, but it is still expected that the crop will be about 40 million pounds. New Brunswick –The start of the growing season was delayed by 5 to 7 days and blight conditions persisted throughout May. This delay benefited the beekeeping industry, as it allowed beekeepers to build up their numbers and bring hives to pollination strength during that extra week. The weather during pollination was good in most regions. The month of June was dry but recent showers have improved crop outlook. The crop looks to be better than the average 20 million pounds and could exceed the record of 24 million pounds. Prince Edward Island – The was crop 10-14 days later in development compared to last year. Winter kill was about average and there were lots of infection periods for Monilinia blight. During early bloom, the temperatures brought on the blossoms for the early clones but then cooled off and delayed blossom for later clones - the result was a spotty or uneven fruit set. Some growers complained of lack of blossom in some fields and foliar leaf diseases have resulted in weaker buds. Overall it is expected to have about the same yield as last year, 8 million pounds. More land is being developed all the time so we expect yields to increase over the next several years. Newfoundland – No report available, but expect an average crop of 1 million pounds. Wild Blueberries - (total wild crop is estimated at 182 million pounds).
The July issue of Cooking Light magazine includes a terrific feature story on color. “Color Your Palate” details how USDA researchers Ron Prior Ph.D. and Jim Joseph Ph.D. began their investigations into the health properties of brightly colored fruits and vegetables…including Wild Blueberries. They found that the more brightly colored fruits and vegetables had the highest antioxidant levels measured through ORAC and also performed well in areas related to cancer, cardiovascular disease, and other diseases of aging like Alzheimer’s. This article generated approximately 5 million reader impressions! Additionally, Shape Magazine covered berries from a different angle- as a dinner item. Shape uses the ORAC number for wild blueberries as the representative number for all blueberries. This article generated another 5 million impressions! The new consumer brochure has been printed. Recipes used in the brochure as well as a few additional favorites have also been added to WBANA’s Wild Blueberry website www.wildblueberries.com Background About Mummy Berry Disease Mummy berry blight requires three factors to develop: 1) susceptible buds on the blueberry plants, 2) the spores of the mummy berry fungus and 3) suitable weather to get infection. Each of these factors can be easily monitored to determine how likely it is the mummy berry fungus has infected blueberry plants in a particular field. Blueberry leaf and flower buds are susceptible to the mummy berry spores once the bud scales have separated (bud scales are the brown protective hard leaves that cover the buds in winter). The buds continue to be susceptible to this fungus as they develop. The end of the period the plant is susceptible to the fungus occurs when the mummy berry cups stop producing spores. About mid-April, mummy berries in the field start to develop small cups that produce the infective spores. These spores are carried by the wind and land on developing blueberry leaf and flower buds. The spores do not survive for long on the buds and require a long enough period of wetness on the buds to get into the plants. Either rain or fog, but not dew, can provide this leaf wetness. The fungus grows slower at cooler temperatures so longer period of leaf wetness are required for infection than at higher temperatures. Eventually the mummy berry cups shrivel up and no more spores are produced and no more infection will occur. Mummy Berry Forecasting - 2007 Season In the 2007 field season, the development of blueberry buds and mummy berries and the weather conditions were monitored to provide a forecast of mummy berry infection in different blueberry growing regions of the state. Blueberry bud development was measured by taking a sample of stems from a field, once or twice a week depending upon how fast the plants were developing, and counting the number of buds whose bud scales had separated. From mid-April to the end of May, mummy berries were looked at to determine if they had cups that would be producing spores. The duration of rain or fog and the average temperature during the rain or fog were used to estimate the chance of infection by the mummy berry fungus. One of the key factors that differed between the regions was when the mummy berries had cups that were producing spores. What days the cups shriveled up and stopped producing spores varied by up to a week in fields that were only an hour apart. Drainage and the soil type in a field also had a large effect on how long the mummy berry cups produced spores. Setting Up Your Mummy Berry Patch – NOW For the 2008 season, I encourage you to set up your own mummy berry patch in a field that will be crop bearing in 2008. This way you can tell when the mummy berry cups are producing spores in your field and so when you may need to start and stop applying fungicides to protect your plants. During harvest, you will need to collect about 50 mummies, picked off the plants or ground, from your crop bearing fields. In your next year crop field, find a hollow that won’t have standing water in it and put the mummies in a small area of soil cleared of plant debris. Then press the mummies into the soil with your foot and cover them with about 1/8 to 1/4 inch of soil (don’t cover them with too much or they won’t produce cups in the spring). Put two stakes on either side of the patch so you can find it in the spring. This patch will not increase the amount of disease in your field since you will be timing when you spray fungicides to prevent the fungus from infecting your plants. You should start monitoring for cups about mid-April. Questions? Please contact Seanna Annis, Blueberry hotline 1-800-897-0757 x 3 or sannis@maine.edu. Sincerely,
David E.
Yarborough
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