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WSU Tree Fruit

Cherry Calcium Management Update

A summary of a presentation by Dr. Yan Wang, Assistant Professor, Postharvest Physiology, Oregon State University at the Washington Tree Fruit Research Review 2016. Summarized by Tianna DuPont, WSU Tree Fruit Extension. Reviewed by Dr. Yang Wang. February 5, 2017. Updated May 2018.

Calcium is critical for strong cell walls and good postharvest quality of fruit. Cherry fruit needs 600-800 ppm of calcium in order to have good storage quality. When calcium concentrations are lower pitting is more likely and fruit flavor may not be as good after shipping. However, often fruit is calcium deficient. From 2013 to 2015 Yan sampled five to ten orchards per cultivar and found variable calcium levels in fruit.

How Do We Increase Calcium Content in Fruit?

Calcium management should be part of an integrated program.

For example, using a calcium nitrate product with 11% calcium 1 gal per 100 gallons would give growers 0.11% calcium within the 0.1 to 0.15% range.  2 gallons per 100 gallons of a calcium nitrate product with 7% calcium would give 0.14% also within the 0.1 to 0.15% range.

In another example using a 19% calcium nitrate (Ca(NO3)2 dry) to achieve a rate of 0.1% you would use 4.4 lbs calcium nitrate per 100 gal.**

In Dr Wang’s recent study he found that the previous recommendation of three calcium applications did not increase concentrations of calcium in the fruit. Six applications between pit hardening and harvest was able to increase calcium levels from 450 to 650 ppm. Nine applications did not do a better job than six. Early applications before pit hardening were also not effective. The concentration of Ca2+ was also important. Ca2+ between 0.1 and 0.15% performed the best. Ca2+ of greater than 0.2% increased the potential for leaf burning and reductions in fruit size. Ca(NO3)2 or chelated Ca is recommended. Calcium chloride is not recommended on cherries.


osu-tagDr. Yan Wang

Assistant Professor, Postharvest Physiology

Oregon State University

(541) 386-2030
Img1380Tianna DuPont
WSU Extension Specialist, Tree Fruit
(509) 663-8181 ext 211
(509) 713-5346 (cell)



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