Mummy Berry Forecast Post #7– May 25th, 2022

Thursday, May 26, 2022

 Monilinia blight infection symptoms from this year

As I mentioned last week, we are expecting to see monilinia blight symptoms this week as the crop moves into bloom.  

These symptoms are from untreated Bluegold which is a fairly susceptible variety.  

We observed symptoms on both leaves ( pictures 1 and 2) and flowers (picture 3). 

This blighted tissue will produce conidia, which will be moved to flowers by pollinators, wind and rain.  This secondary infection is very difficult to control, with fungicides, which is why we emphasize the timing and application of fungicides for the primary infection. This dying tissue is attractive to pollinators and under favourable conditions magnifys the amount of disease in the block. 

Over the coming  weeks, as the fruit develops, I'd expect to see fruit infections show up and I hope to bring you updates on the disease development. 

On an unrelated note:   Jeff Franklin from AAFC points out that Kentville is experiencing “drier than average conditions so far this May  we have received only 26.5mm of rain in May compared to the 10-year average of 69.3mm (for the entire month of May). As a comparison, in 2021 we had 106.0mm of rain in May.”      Growers should be monitoring soil moisture earlier this year, usually it may not be on our minds to irrigate in May.  I am noting many nutrient deficiencies showing up in a number of berry crops and this may be a result of increased demand from the plant as the crop moves from a vegetative to a reproductive phase but also the drier than expected conditions.    The other thing I’m noting is that some of the residual herbicides have not had an “activating rain” and some weeds have broken through.   Depending on the herbicide product and the size of the weeds, the herbicide may be able to take these small weeds down if rain comes on the weekend.

Many thanks to Jeff Franklin for compiling the weather data and calculating the Growing Degree Days below.  



Mummy Berry Forecast Post #6– May 19th, 2022

Thursday, May 19, 2022

All apothecia were dried up when checked this morning, at the Monilinia monitoring sites I use in the Berwick-Aylesford area.   I believe we are past the window for Monilinia primary  infection for most highbush blueberry production areas in Nova Scotia.  Most growers  got through the season with applying 2 well timed sprays for the control of Monilinia Blight.  Some early varieties, would have received three sprays, as their infection window is slightly longer than other varieties and their development is slowed by cooler weather.

It is important for growers to monitor for infections in order to evaluate their Monilinia spray program so that they can make better decisions on application timing and products in the coming years.   If primary infection has occurred, shoot, leaf and bloom blight will show up early bloom, which may be as early as next week on some varieties.      

These blighted tissues will produce conidia which can be moved to the flower by wind, rain splash and pollinators. Once this secondary infection takes place Mummified fruit will develop and drop to the ground near harvest and carry inoculum for the disease into the next year.  

This second phase of the disease is next to impossible to control, so well timed fungicide applications are necessary to control the primary infections.

I believe, I have a site that will show the second phase of the disease development and will try and update the blog with symptoms as the disease develops. By being able to recognize infections and gauge disease pressure we will be better prepared for spring 2023.

Special thanks to Jeff Franklin of AAFC for compiling the data for the tables above.