3rd Monilinia Update for Nova Scotia, April 30, 2021

 

This is our 3^rd Monilinia update for this year.

 

Here is some information I like to share with you this week:

Winter damage on floral buds: this past winter, we had low snowfall and little snow coverage in blueberry fields. I have concerns about potential winter damage on floral buds over the winter. When I did blueberry stem bud counts over the last few weeks, I observed minimum to no winter damage on floral buds in Colchester and Hants. The average floral bud numbers in those areas range from 6-12.

Vegetative buds development in crop year fields: vegetative buds start to grow and reach V2 and above stages (Figure 1).

                                     Figure 1. Vegetative buds at V2 and above stages

 

 Plant development and potential Monilnia infection period:

In southwest NS and fields in Hants county, blueberry plants have reached 40% and above F2, therefore, growers in those areas should watch for the forecast closely for the wetness periods.

In most of the areas I monitored in Colchester, fields are reached 40% F2 or soon will reach F2 (30% and above). In Cumberland, some areas also hit 40% F2 and other areas will hit 40% F2 shortly as well.

Some early fields had infection periods before today (April 30) and I noticed some growers sprayed for monilinia already. With the expecting wet period next week, there will be some infection periods in fields with 40% F2. Please monitor your weather forecasts closely! This infection severity chart shows the infection risk level by wetness duration and the temperature during the wet period. When temperature increases, there is a shorter wetness duration required for infection.

Figure 2. Severity rating of Monilinia infection periods

 

Figure 3. 3^rdMonilinia Update for Nova Scotia- April 30, 2021

*Please click on the image to zoom in to see a clear view of the map.

 

Table 1. Monilinia Update for Nova Scotia- April 30, 2021

Wild blueberry production regions, NS	The average percentage of floral buds at F2 or beyond
South West Nova Scotia	Above 40-50% F2, please watch for the forecast
Hants County	Above 40-50% F2, please watch for the forecast
East Gore	60%
Upper Rawdon	50%
Halifax County	NA
Guysborough County
East River Saint Marys	30%
Colchester County
Greenfield	30%
Camden	33%
Debert	30%
Earltown area	20%
Bass River/Portapique	45%
Baseline Rd.	36%
Londonderry	34.6%
Great Village	45%
Portapique	30%
Westchester Mt.	>40%
Cumberland County
Springhill	22%
Oxford	56%
Amherst	41%
Parrsboro	21%
Southampton	34%
Vewville	39%
Collingwood and Windham Hill	30%
Pictou and Antigonish County	NA
Cape Breton	NA

The next update will be on Friday, May 7.