Regarding leaf and petiole analysis

[Masbustelo]

I'm considering, or rather planning on doing a leaf/petiole analysis this year. I have no experience with this. I assume it is best done early in the season? When and how should it be done? Does it matter which lab I use? I am in Northern Illinois, border with Iowa. Any information is appreciated.

 

[ibglowin]

July to August is the best time of the year usually.

https://www.extension.iastate.edu/wine/files/page/files/072711domotograpepetiolesampling.pdf

 

[Masbustelo]

Have some of you done petiole analysis in the past, or do so with ongoing regularity? If so what were some deficiencies identified, and how did you treat for them?

 

[balatonwine]

Interesting.

I did not even know about this.

I read the document. At one vineyard I have soils which are quite variable. Would be hard to demarcate exactly for such analysis.

But I am a relative small fry. Only have one hectare (2.4 acres) and kind of go it by feel and observation what I need to do to help my vines. Seems this is more a technique for larger growers with a lot invested and need minute management methods to optimize harvests and income.

 

[Masbustelo]

At harvest I am having Ph close to 4.0, and suspect high K levels, which in turn cause Mg deficiency signs toward the end of the year. This is my diagnosis, but a known problem with Northern Hybrids grown on fertile soils. So I'm thinking about the petiole analysis to see if I am diagnosing correctly, and what Possible treatment there might be.