Is boron deficiency the cause of this internal browning discoloration in celeriac? Photo: Jennifer Glenister
Recently two celeriac growers reached out to Penn State Extension after observing brown discoloration and hollow heart in the internal flesh of celeriac roots last summer. While the growers and I suspect that boron deficiency is the issue, our evidence is anecdotal rather than research-based at this time.
If you grow celeriac and have dealt with brown discoloration and/or hollow heart could you send me an email (firstname.lastname@example.org) or note that provides me with the following:
- Celeriac varieties grown (please note the severity of symptoms noticed in specific varieties)
- Soil test results, specifically pH, calcium, potassium, zinc, and boron levels.
- Irrigation rates (some growers report providing up to 2 inches of water per acre per week to celeriac). *Moisture stress limits nutrient uptake so irrigation rates are important.
Send to: Tom Ford, Penn State Extension, Cambria County Office, 401 Candlelight Drive, Suite 220, Ebensburg, PA 15931
Celeriac, which is also sometimes called “Knob Celery” is considered a minor crop on many Pennsylvania vegetable farms, but to some direct marketers it is becoming a staple in their late summer and winter markets. Celeriac has a similar taste profile as the more traditional celery and has been used as a food crop since the 1600’s. The bulbous root has a pearly white flesh and it can be stored for 3-4 months under ideal conditions. As a minor crop there has been very little research on celeriac so when a cropping issue arises it is difficult to obtain the research-based information needed to manage the crop.
In the interim, I have found literature from the Netherlands that suggests that celeriac requires a boron soil test level of 1.4 ppm. Growers with fields testing below the 1.4 ppm boron level were more likely to observe boron deficiency in their celeriac. This data also suggests that fields with a soil pH over 7.0 will limit boron availability and increase the likelihood of boron deficiency in celeriac. High soil calcium levels and high zinc levels in the soil can also lessen boron uptake by many crops and in one case the grower reported both elevated calcium and zinc levels in the soils where celeriac internal browning symptoms were observed. Data on celery also suggests that elevated soil potassium levels will increase the incidence of boron deficiency so it is possible that a similar scenario could be observed in celeriac as well.
According to some older research data from the Netherlands there appears to be varietal sensitivities to boron deficiency and symptom expression in celeriac. The variety Oderdorfer was considered highly susceptible to boron deficiency while the varieties Roka, Magdeburger, and Markt only displayed symptoms occasionally. Varieties Dippes, Invictus, Hilds Neckarland, and Wiener Markt typically did not express any symptoms according to the Dutch study. So far, our Pennsylvania growers have noted internal browning in the varieties Mars and Brilliant.
If you are growing celeriac and have enjoyed good success please consider sharing your data with me so we can help our celeriac growing community in Pennsylvania.