Mummy Berry 2019 #7

Tuesday, May 21, 2019

Since the last mummy berry post there have been three extended infection periods between Tuesday May 14-Wednesday May 15, Friday May 17-Saturday May 18, and Monday May 20-Tuesday May 21. From observations made Tuesday May 21 the majority of  blueberry varieties are past the F2 stage, and some varieties are beginning to approach pre-bloom. Viable apothecia cups are still present with the rain and lack of sun helping them persist, but decline is beginning to occur. If you applied a protective spray before or after the infection period Friday May 10 you should have had control through the week and most of the weekend. If you did not get on another protective spray before the infection period Monday May 20 you can still use a product with back action (Topas, Mission, etc) to achieve control within 72 hours of the infection period. If you have applied two back to back sprays of a group 3 fungicide (Topas, Mission, etc), then a non-group 3 fungicide such as Diplomat 5SC should be used for resistance management before applying an another group 3 fungicide. An ideal time to apply another spray would be Wednesday afternoon when the rains breaks temporarily as it appears there will be two more extended infection periods between Thursday May 23 and Sunday May 26.

As a reminder these recommendation are based off of observations made in the Annapolis Valley and may not be applicable to your region or field. The decision to spray should be based off of observations and weather conditions from your specific site. For more information on highbush blueberry production, mummy berry, and pesticides refer to Management of Mummy Berry Disease in Highbush Blueberry and Highbush Blueberry Management Schedule 2019.   

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