24 Aug Agronomy Update – Aug 24
I’m sure that many of you are busy trying to get potatoes sprayed and grain harvested ahead of the anticipated rain this weekend. The most recent forecast is calling for 50-75 mm of rain on Saturday, with an expectation of rain again mid-week next week.
Of course I’m not saying anything that you all don’t know, but this amount of precipitation is sure to cause some issues. I am already hearing reports of water soak and enlarged lenticels on early harvested acres. Growers will have to be very aware of compromised potatoes this year, as I’m quite certain that it will be a more challenging storage season for some acres this year. After the rains over the next 7 days, be diligent to mark any areas where you see standing water, as those acres should be dug last (if at all). Sprayer tracks should also be viewed with caution…lots of those sprayer tracks have had standing water in them repeatedly this summer and are sure to have a higher proportion of compromised tubers. The conditions this year are also favourable for pink rot, so use of phosphorus acid products either foliar or going into storage is likely recommended for many varieties.
Spornado results (Aug 22nd):
- All sites negative this week for late blight.
- Bortrytis (grey mold) positive at two sites (Freetown and Morell).
Airspore results (Aug 22/23)
- Late blight spores detected in O’Leary and Urbainville (4 spores at each site)
- These same sites have now detected spores multiple times this season.
- Early blight spore numbers have decreased to zero at most sites
- Brown spot (Alternaria alternata) has increased at a number of sites as foliar matures and starts to settle down. However, counts are still zero at the majority of sites.
- Grey mold (Bortrytis) counts have increased substantially at a number of locations, particularly in East Prince and along the north shore from New Glasgow/Cymbria to East Point. Some counts exceeded 10,000.
- With cooler nights and excess moisture, grey mold can easily occur in susceptible varieties at this time of year. For those with susceptible varieties, rotating Bravo/Echo into the spray schedule would be advised. Mancozeb products are not effective at controlling grey mold.
Aphid Alert: Up to Aug 18th
- I’ve attached a graph of the aphid collections averaged per trap per week for other aphids, green peach aphids, and potato aphids.
- While we detected green peach aphids much earlier than last week, numbers per trap have remained under 1 so far and have decreased the last two weeks. We saw the big explosion in green peach aphids in week 10 last year, so we will remain vigilant.
- Other aphids have increased slightly in recent weeks, but number remain much lower than average.
- Potato aphids have also appeared in the last 3 weeks, but numbers also remain generally low.
- I see that quite a few seed fields have already been top-killed. Reports from some growers are that seed sized up quickly and that yields were strong, so it was decided to kill a bit earlier than normal.
- Lots of folks battling with high levels of DON in wheat and barley this year, as I mentioned in my last update. There will be quite a few fields not harvested due to high DON levels. Be sure that if you are not harvesting grain that you have a strategy on what to do with that field for next year. Two tons of grain per acre makes for a lot of potential volunteer seed over the next couple of years if not managed properly….as well as a source of future Fusarium infection. Keep this in mind when making management decisions with these fields.
Crop Update Meeting:
- The next Crop Update Meeting will be next Tuesday, August 29th at 8:00 am at the AIC Boardroom in Kensington.
- All are welcome to join in person or on Zoom.
I hope you have a good weekend…and that we don’t get as much rain as the current forecast says!