Easing into potato harvest and storage

Editor's note: this article was updated with links to products and pests in 2023.


Harvest of the early crop is almost done, truckloads of the field fry crop is headed to the plant and we are gearing up for the start of harvesting the main crop.

As potatoes begin to come out of the field, consider the conditions and crop quality to help those tubers going to the pack house or into storage.

Late blight in the neighbourhood?

Check in with your crop consultant to find out if late blight has been detected in your local growing region.

Rainfall or mornings with heavy dews create a perfect environment for late blight to flourish in the potato crop. In these conditions, consider finishing the season with Allegro^® fungicide.

Allegro was first tested in potatoes in the late blight hot zones of Europe – Belgium and the Netherlands. So, how did Allegro perform?

• In Syngenta tuber blight trials Allegro provided 88 percent control of tuber rot, even in high pressure conditions (Syngenta trials, 2005, n=5)
• The standard, mancozeb, provided no control (Syngenta trials, 2005, n=2)

At 0.16 L/acre, Allegro applied prior to top kill stops the swimming spores before they infect the tubers. So how does it do that?

• In a Syngenta lab study conducted in the UK, in a 1 percent solution, Allegro reduced the motility of the swimming spores by 98 percent (Syngenta research, 1994, n=1).
• Mancozeb reduced motility by just 61 percent (Syngenta research, 1994, n=1).

GO DEEPER: Watch this video to learn how late blight infects the tubers 

Ready to top kill?  

Weeds? Heavy top growth? Soggy fields? Drought-stressed plants? 

Potato vine killing is an art, and one method doesn’t suit all conditions or regions. If using Desica^® desiccant, check out the label for further guidance.

Growing processing potatoes?

If your chipper variety is particularly susceptible to Fusarium, defend your crop with an application of Stadium^® post-harvest fungicide.

Certain processors have approved Stadium for use. Check with yours to find out if Stadium is on their approved product list.

Growing table potatoes?

Quality starts at planting, but if the potatoes are headed for storage, marketable yield isn’t determined at harvest.

If you want to maintain clean skin on your table potatoes, protect your yield with an application of Stadium.

GO DEEPER: Watch this video to learn how silver scurf spreads in storage  

With Stadium, coverage is key

In order for Stadium to be effective, coverage of the entire potato is required, however, treated potatoes should be just barely wet.

Stadium is applied at 32.5 mL/metric tonne of potatoes, and the total slurry volume should be 2 L per metric tonne, highlighted below in green:

Performance evaluations are based on internal trials, field observations and/or public information. Data from multiple locations and years should be consulted whenever possible. Individual results may vary depending on local growing, soil, and weather conditions. 

Please check with your processor or packer prior to using Stadium on potatoes destined for use outside of Canada. At time of writing, Maximum Residue Limits (MRLs) had been established for the active ingredient difenoconazole for export markets in the United States, Japan and Korea, Please see the Bryant Christie Inc. Global MRL database for a complete list of MRLs. Should you need additional information on export market MRLs, please consult with Syngenta to receive the most up-to-date information. 

Always read and follow label directions. Desica^®, Reglone^®, Stadium^® and the Syngenta logo are trademarks of a Syngenta Group Company. Allegro^® is a trademark of ISK Biosciences Corporation. © 2023 Syngenta.