Mummy Berry Forecast - May 4, 2011

Wednesday, May 4, 2011

Prerequisites for Spray Decision:

1. Past history of Monilinia Blight on the farm.
2. Flower buds become susceptible to infection at the F2 stage (bud scales separating).
3. Once fields reach 40-50% F2 and beyond, a fungicide is required within 72 hrs of the start of an infection period. This application will provide 7-10 days protection.

Observations at Tim Strong’s farm as of May 4th, 2011:

Conditions are now ideal for infection – many blueberry varieties are at or beyond the 40-50% F2 stage and mature apothecia cups are present and actively sporulating.

Mature apothecia cups on May 4th at Tim Strong’s Farm on Brooklyn Street in Kings County.
















Recommendations:

Since bud development stage (for many varieties) is optimum for infection, and mature apothecia cups are actively sporulating, steps should be taken to protect buds from infection (if there is a history of disease in the planting). The forecast for Kentville is for drizzle overnight and rain on Thursday so two strategies for infection prevention may be employed. Firstly, a fungicide can be applied prior to the expected wet period or alternatively Topas, Mission, or Funginex must be applied within 72 hrs of the beginning of the wet period for “back-action” control. If a fungicide was applied previously it would provide 7-10 days protection so this should also be considered in the application schedule.

Keep in mind that this recommendation applies to Tim’s farm in King’s Co. only and it is a guide only for other farms. If you are west or south of Tim you may well be ahead of him in development, and if you are east of him you may well be behind him in development.

Refer to “Management of Mummy Berry in Highbush Blueberry” factsheet for pictures of F2 stage and temperature and wetness requirements for an infection period.

Refer to AgraPoint’s “Hishbush Blueberry Insect and Disease Management Schedule” for a list of registered products for mummy berry (Monilinia) control in highbush blueberry.

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