Forecast Impacts
By now, weather information statements for tropical storm Elsa are making their way to everyone in the Maritime provinces. No, unfortunately this storm is not the Disney princess Elsa having a bad day.
"Tropical Storm Elsa is currently near the Gulf coast of Florida. Elsa is expected to track across the Maritimes as a Post-Tropical storm early this weekend bringing significant rain to parts of the region."
At this time, the forecast impacts are the following:
- Winds gusting to 60 or 70 km/hr just south of its eventual track through the region
- Areas along and north of its eventual track receiving rainfall in excess of 50 mm
For current information, continue to monitor the hurricane track and active alerts.
Figure 1: The Tropical Cyclone Information track issued by Environment Canada's Canadian Hurricane Centre at 9 AM on Wednesday, July 7.
Preparedness for Apple Orchards
The following are recommendations to help you prepare for damaging winds, should they occur.
- In the dry weather before the rain is forecast to begin on Thursday night, work on supporting young trees. (Work in dry weather especially if the block has historically high risk of fire blight.)
- Check on support for trees that are known to be brittle at the union, including many of the new Geneva rootstocks (G.11, G.41, G.16 etc).
- Have streptomycin available to treat orchards within 24 hours of exhibiting damage to foliage or limbs.
- Ensure that equipment is accessible if it will be needed for recovery, including saws, shovels, fuel, equipment parts, and knowledge of the location and cost of other equipment.
Figure 2: Work on supporting young trees in the dry weather before potentially damaging winds.
Reminders about Fire Blight Trauma
Wind that damages plant tissues is a fire blight trauma event in which fire blight bacteria have access to open wounds to enter and infect tissues.- Streptomycin provides optimal control when applied within 12 hours of a trauma event. This early timing targets bacteria that have entered shoot tips before they spread further and initiate a significant infection. Application up to 24 hours after trauma is still good but is likely not as effective as early treatment. Include Agral 90 surfactant at 500 mL per 1000 L as a spreader/sticker to improve efficacy.
- Streptomycin should not be used as a preventative treatment in the case of a tropical storm and should be saved for post-infection activity. If applied before trauma, streptomycin can be washed off leaves, degraded by sunlight, and will not provide protective activity if bacteria is moved in from outside the orchard.
- Do not rely on Kasumin for a trauma event because this antibiotic is not systemic and will only kill cells on the surface of leaves and shoots. Meaning, any bacteria that moves into tissues will not be affected by Kasumin or copper.
- Apogee could be applied immediately if not already applied. The protective effects of Apogee will not be active during the storm but the eventual protective activity may limit systemic spread of the fire blight bacteria in infected shoots.
- A rotating storm system with wind and rain moves bacteria around and between orchards with the potential to spread infections to new blocks.
And in the end, hopefully this is all in the name of being prepared for an event that doesn't happen!
