# Seminars in France, November 6 & 7, 2023

## Notes

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Find turfgrass reference information, site-specific weather and climate appraisals, and weekly updates at the PACE Turf information center.

For more about MLSN, see this article by Romain Giraud: NMND : niveau minimum pour une nutrition durable des greens de golf.

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## A Cynodon question at Saint-Endréol

At St. Endreol, I showed the C3 growth potential (GP) (above) and mentioned that I would make a chart and calculate the estimated N rate that might work well for Cynodon at that location.

The estimated N that I expect for these temperatures for Cynodon is 142 kg/ha (14.2 g/m2).

## How do I get those N values?

I use maximum monthly N amounts that are linked directly to GP. For bentgrass, I assume that when the GP is 1, the maximum N applied would be 20 kg/ha. That, for Agrostis, is with a C3 GP. For Zoysia with a C4 GP, I also use 20. For Festuca rubra, 20, maybe even 15. For Paspalum vaginatum and Poa annua I use 30. For Cynodon and Lolium perenne I use 40.

With Agrostis, the sum of GP is 207 days. The monthly maximum N I would use is 20, or 240 if all twelve months had perfect temperatures. This is $\frac{240}{365}=$ 0.66 kg/ha/day. If I multiply that daily value by the sum of GP, I get the estimated annual N of $\frac{240}{365}(207)=$ 136 kg/ha. That’s for Agrostis.

For Cynodon, I’m using C4 GP and a monthly maximum of 40 kg/ha, so the annual total comes to $\frac{480}{365}(108)=$ 142 kg/ha.

## For the mountain courses …

If you sometimes have winter damage from snow or ice at your location, please consider providing information to the Winter Turf project.

## OM and videos and podcasts

See more about OM246 testing, including sampling instructions and a sample report, at the OM246 project page.