Mummy Berry Forecast Post #1 – April 18th, 2023

Tuesday, April 18, 2023

Mummy berry and Monilinia blight infection timing is almost upon us.   The 2022 season started early and stretched out late and therefore went through several rain events.   Some growers therefore made several fungicide applications in order to get them through the several infection events. Let us not forget we need three conditions for disease to occur:

1.  Inoculum presence - mature sporulating apothecia cups

2.  Susceptible host at the correct bud development stage – bud scales separating in flower buds (F2 stage)

3.  Suitable weather conditions – long wet periods at relatively warm temperatures.

If you need a little primer on Mummy berry, also called Monilinia Blight, please take a few minutes before the season to review this short video:  Mummy Berry Video.

In preparation for an infection period, make sure you have product on-hand.

Products with the active ingredient propiconozole (Pivot, Bumper, Tilt, Princeton, Fitness etc) can be applied after an infection event, providing up to 72 hour ‘back action’, in addition to being excellent protectants against future infections for 7-10 days after application. Quilt is listed as a preventative fungicide, but also displays systemic and curative properties.

A complete list of registered products can be found by consulting the table below or by clicking here

In this table the rating of 3 provides excellent control.  

At this time buds on the early varieties such as Bluegold are at 10% F2.  I have not been able to find any emerged apothecia at this time.  There is no rain forecast therefore the risk for infection is very low.  

Weather data from Jeff Franklin: AAFC

Precipitation summary for Kentville using rainfall and rainfall equivalent (snow) data.

2023 Degree Day Accumulations

Table 1.0.  Degree day accumulations as of April 17, 2023.  All data are taken from the Environment and Climate Change Canada weather station located at the Kentville Research and Development Centre. Calculations are based on a start date of March 1, and calculated using the single-sine method.

  Many thanks to Jeff for compiling this data for us.