23 Mar Agronomy Update – March 23

Hi everyone.  According to the calendar, spring has arrived…but according to the weather forecast, winter is definitely still a present reality.

This week I attended the Northeast Potato Tech Forum in Fredericton, where researchers from PEI, NB, NS, QC and ME presented updates on their research while also providing the opportunity to connect and collaborate.  After some lost years due to COVID when only virtual options were available, it was nice to be back in person to connect with those in the Northeast potato research community.  It was also nice to see that PEI was well represented, with several projects supported by the PEI Potato Board, either financially or through providing information or direction.  Abstracts from the Forum are available at www.northeastpotato.com.

CanPEDNet – Key learnings about Potato Early Dying:

Over the past four years, I have been leading the PEI component of the Canadian Potato Early Dying Network (CanPEDNet) research project under the National Potato Cluster.  This has consisted of fall soil sampling surveys of potato fields across PEI going into Russet Burbanks the next year, followed by additional follow up sampling in the potato year in a subset of high and low inoculum fields, based on the fall survey results.

I have posted a summary of PEI results and key take-home messages from the CanPEDNet project to the Agronomy Site.  We were able to learn quite a bit from this project, and hopefully this information will be valuable to producers as we learn to manage PED.  A big thank you to all of the producers who provided fields for this project!

New SpudChat episode – Dr. Mario Tenuta

Speaking of the CanPEDNet project…the latest episode of SpudChat is with Dr. Mario Tenuta of the University of Manitoba, discussing some of the results of the CanPEDNet project from both PEI and the rest of Canada.  You can listen to the episode here or wherever you download your podcasts.

Colorado Potato Beetle – Insecticide Resistance

For the past four years, PEI producers have been submitting samples of Colorado potato beetles with the assistance of the PEI Department of Agriculture & Land to AAFC for insecticide resistance testing under the FVGC National Cluster Project.

In the first two years of analysis, the majority of insecticides came back as highly effective, with most samples being rated as having greater than 70% mortality.  Entrust had 3 out of 8 samples come back as having reduced susceptibility, and none of the insecticides fell into the Resistant category (< 30% mortality).

However, the story changes a little in 2021-2022:

We now start to see a little more reduced susceptibility to Titan compared to the first two years of the study.  While Actara showed similar levels of effect to 2019 and 2020 samples, it was only included in the analysis in 2021.

Where we start to see increasing levels of resistance is for the group 5 insecticides, Delegate and Entrust.  There is also some reduced susceptibility in varying amounts to some of the group 28 insecticides (Vayego, Harvanta, Exirel), though none of them show as resistant.  Newly tested in 2022 is Agri Mek, a group 6 insectide.  Five out of six samples tested for Agri Mek were showed to be susceptible.

What does this mean for producers?  The two neonic products (Actara and Titan) have been doing the heavy lifting for CPB control for many years now, but we’re starting to see some reduction in efficacy.  Titan is also now only available as a seed piece treatment.  If you are seeing CPB escapes requiring foliar application, you might want to look at alternating groups if you don’t see good levels of control.

It should also be noted that we saw the highest level of reduced susceptibility to insecticides in West Prince.  This region has been reporting more CPB in recent years, so this is not a great surprise.  Agri Mek performed the best in the West Prince samples from 2022.

If you have any more questions about these results, please feel to give me a call or send me an email.  I hope to have the full CPB project report to share with you later this spring.

Have a great rest of the week!

Ryan