In the Berry Field: Sonny Murray discusses Mummy Berry

In this issue of In the Berry Field, Sonny Murray discusses Mummy Berry in Highbush Blueberry.

The video can be viewed by Clicking Here

Chlorothalonil (Products Bravo and Echo) under review again:

The future use of Bravo on berries may be lost

Health Canada is proposing continued registration of chlorothalonil (Bravo, Echo, and others) on greenhouse ornamentals; however, all other uses are proposed for cancellation.   In highbush blueberries, chlorothalonil has activity on Mummy berry, Phomopsis stem cane, Anthracnose fruit rot, Botrytis fruit rot, and Alternaria fruit rot.   In strawberries, chlorothalonil, is often the backbone of the fungicide program, having activity on Anthracnose, Botrytis gray mold, Common leaf spot, Leaf scorch and Phomopsis leaf and fruit rot.  Chlorothalonil is one of the few Class M (multisite) fungicides available.  Without it in a rotation with other fungicides, growers will be forced to rely on single site fungicides which all pose a greater risk of pathogens developing resistance.   Growers will be able to use Bravo and Echo on labeled crops in 2022, but the proposal will see the phase out of Bravo and Echo in the near future.   If you would like to find out more about the proposal please follow this link .   You will have a chance to voice your displeasure (which I’m hoping you will) by following this link.

Losing functional fungicides from our toolbox really scares me as it leaves the industry with less fungicide groups available in their fungicide rotation to manage the development of fungicide resistance.  New fungicides and fungicide groups are not being added at the same rate that existing chemistry is being lost.  

In order that the Fruit and Vegetable Growers of Canada can respond effectively during the PMRA’s consultation period for this Special Review, grower input to two surveys on how chlorothalonil is actually used is essential. In the absence of this additional information, PMRA must use the most conservative scenarios during their risk assessment process (e.g., 100% crop treated, maximum possible application rates, etc.).

Responses to these surveys, which are anonymous, are requested by no later than April 15, 2022. The surveys can be found at:

• Fruit and Vegetable Survey: https://www.surveymonkey.com/r/NJ3WJHF
• Potato Survey: https://www.surveymonkey.com/r/P98D3Q7

I encourage you to forward this email to other growers. Fruit and Vegetable Growers of Canada would like to thank growers in advance for completing these surveys.

Winter cold damage 

Fruit bud set was looking very strong going into winter, no doubt promoted by the early harvest and strong fall.  Checking a number of strawberry and raspberry patches in Nova Scotia this spring, it is not hard to come across some winter injury.   The first really cold event occurred on December 9^th, ranging from -15 to -17 c on the weather stations I checked.  -17 is not particularity cold but after the tremendous weather in October and November it is hard to determine if the plants were truly dormant.   Many growers waiting to put chateau on may not of had their straw on at this point.   There where also a couple of consecutive cold nights in January which may have been the culprit.  January 22, at the Kentville Research Station registered -22.4. But looking at the NSFGA-Aylesford weather station the same night registered  –27.9, NSFGA Grafton weather station was -25.1.     I believe this drives home the need for a good layer of straw.  I often get the question of: how much is enough straw?    There is not a lot of information on this, but I was able to pull these numbers from Maine and convert them to more useful numbers.   400 small square bales of straw per acre or 25 round bales per acre (assuming there are 14 small square bales in a round bale) for 4 inches of straw mulch, or 4 tons/ac.  Many growers looking to economize or mechanically spread may not be putting on the proper amount.  In the past, when we could count on a good layer of snow, we could get away with a thinner layer of straw.  With the freeze- thaw cycles in recent years, this is much riskier.  The insulating value of ice is not nearly as protective of a good layer of fluffy snow.  The strong winds are also working against growers, moving the straw off hills, or beds. Many are going out multiple times to reapply straw to wind swept areas. 

 

In strawberries crowns are usually safe to -12 c. (10F). In strawberries cold damage to crowns presents itself usually starting at the tops of the crown and moving downwards as a darkening of the centre tissue. This darkening will be more advanced as the damage gets worse.  Weak plants with smaller crowns will show more damage and have less yield potential.

 

In raspberries bud hardiness is much more dependent on variety than in strawberries. Slicing open buds will reveal brown tissue behind the bud. The amount of browning will reveal the extent of the damage.   As damage increases the cane itself may be damaged and not limited to the buds.

 

Yield loss is hard to predict but with damage present, there will be a loss of vigour and an impact on yield.  The transport of nutrients, water and energy in the plant has been disrupted through damage to the xylem and additional stress on the plant (herbicide, lack of water, heat stress) will farther effect yield. Anything that can be done to “baby” these plants along will help to reduce this stress.    This may include fertility management, installing drip irrigation and monitoring soil moisture, managing leaf diseases.