{"id":11140,"date":"2026-11-06T17:01:51","date_gmt":"2026-11-06T17:01:51","guid":{"rendered":"https:\/\/canamek.com\/?p=11140"},"modified":"2026-11-06T17:01:51","modified_gmt":"2026-11-06T17:01:51","slug":"bitter-pit-in-apples","status":"publish","type":"post","link":"https:\/\/canamek.com\/es\/blogs\/articles\/bitter-pit-in-apples\/","title":{"rendered":"Understanding Bitter Pit in Apples and How to Prevent It"},"content":{"rendered":"

Bitter pit in apples is a common physiological disorder that can cause dark, sunken spots to develop during storage. For the grower and the storage operator, that’s a real problem in terms of grading, marketing and long-term storage plans. One thing that can cause those spots is a bitter pit. The damage may not be apparent until after harvest, but the causes of the damage will usually have been present while the fruit was growing. It’s as important to know when the fruit is susceptible as it is to recognize the spots themselves. Linking the orchard conditions to the storage symptoms is key to managing the risk.<\/span><\/p>\n

\"Bitter<\/p>\n

Recognizing Bitter Pit After Harvest<\/b><\/h2>\n

Bitter pit causes small, slightly sunken brown or dark spots on the skin of the apple, with the spots often concentrated at the blossom end (opposite the stem). If you cut beneath the spot, you’ll see dry, brown, corky patches in the flesh. It can obviously have a detrimental effect on market value.<\/span><\/p>\n

Not all brown spots are bitter pits. Bruising, insect injury and other postharvest disorders can leave very similar marks. The location of the spot and the nature of the underlying tissue can be very useful in diagnosis, though in some cases you do need to look at the spot more closely.<\/span><\/p>\n

What Causes Bitter Pit in Apples?<\/h2>\n

Bitter pit is very much linked to insufficient calcium in certain areas of the fruit. Calcium is essential for the integrity of cell walls and membranes. Where developing apple tissue is deficient in calcium, some of the cells lose their integrity and eventually die, resulting in the characteristic corky areas.<\/span><\/p>\n

Low fruit calcium doesn’t necessarily equate to low soil calcium. The problem is often one of getting sufficient amounts of that nutrient into the apples being grown and maintaining the right balance with the other nutrients.<\/span><\/p>\n

Honeycrisp is a useful example. Cornell work found that its fruit took up less calcium than Gala under the conditions they studied, while the peel of Honeycrisp had higher potassium levels. That helps to explain its susceptibility (though other varieties are also affected).<\/span><\/p>\n

Orchard Conditions That Increase the Risk<\/b><\/h2>\n

Several growing season factors will affect the distribution of calcium and the susceptibility of the fruit.<\/span><\/p>\n

Heavy applications of nitrogen can promote prolific shoot and leaf growth, which in turn can increase competition with the developing fruit for calcium. Excess potassium can also upset the balance between potassium and calcium. Both of these are essential nutrients, but too much of either can be a problem.<\/span><\/p>\n

Water is of course important too. Calcium moves into the tree with the water, so prolonged drought or erratic soil moisture could well disrupt its movement to the fruit. The effect will vary with the rainfall, the irrigation, the soil and the stage of fruit development.<\/span><\/p>\n

Crop load and fruit size add another layer of complexity. If a tree is carrying a relatively low crop, then the individual fruit will tend to be larger and may therefore be more prone to bitter pit. Variety, rootstock, tree vigor and harvest maturity can all have an influence. These factors won’t have the same effect in every orchard.<\/span><\/p>\n

Why the Spots Appear in Storage<\/b><\/h2>\n

An apple can have a calcium related problem lurking underneath without any obvious signs at harvest. As the fruit is stored, the affected tissue may break down and the spots may appear. They’re generally going to show up in the first few weeks or months although the timing will vary with the fruit and the way it’s handled.<\/span><\/p>\n

Storage on its own doesn’t cause a bitter pit in apples that would otherwise be unaffected and refrigeration won’t reliably reverse damage that has already occurred in the orchard. Some postharvest treatments can affect the manifestation of the disorder. For instance a warming period used with Honeycrisp to alleviate certain chilling injuries can actually increase the risk of bitter pit, demonstrating that the choices you make in storage have to be made with an awareness of the possibility of reducing one disorder while increasing the risk of another.<\/span><\/p>\n

How to Prevent Bitter Pit in Apples During Storage<\/h2>\n

Practical management begins prior to harvest. You can look at the soil and tissue tests, avoid applying nitrogen or potassium when it isn’t needed, maintain reasonably consistent soil moisture and manage your pruning and crop load to keep the tree from becoming overly vigorous and the fruit from becoming abnormally large. Calcium sprays may be of some benefit in certain programs but the results are variable and they won’t in any case replace good balanced management.<\/span><\/p>\n

Before you go and commit an entire lot to long storage you can at least assess the risk. A team at Cornell has tested a method whereby Honeycrisp samples are taken prior to commercial harvest and held at room temperature to reveal the likely bitter pit problems. That can help you make your decision, but it won’t guarantee anything.<\/span><\/p>\n

If a Honeycrisp block has been producing large fruit on lightly cropped trees then the grower may well go in and look at the samples more closely and consider marketing the higher risk fruit a bit earlier rather than holding it for a longer storage period. Regular storage inspections can also feed into marketing decisions.<\/span><\/p>\n

Reducing Bitter Pit in Apples From Orchard to Storage<\/h2>\n

Bitter pit in stored apples is generally the outward result of conditions that have been established in the orchard. Calcium balance is of course the key factor, but water, nutrition, crop load and variety all have an impact on the risk. Being able to identify the symptoms and assess the fruit prior to long term storage can be of real assistance in making better decisions. The best approach is to have good orchard management in place and to have a realistic view of what storage can and can’t do.<\/span><\/p>","protected":false},"excerpt":{"rendered":"

Bitter pit in apples is a common physiological disorder that can cause dark, sunken spots to develop during storage. For the grower and the storage operator, that’s a real problem in terms of grading, marketing and long-term storage plans. One thing that can cause those spots is a bitter pit. The damage may not be […]<\/p>\n","protected":false},"author":319,"featured_media":11148,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[84],"tags":[],"class_list":["post-11140","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/posts\/11140","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/users\/319"}],"replies":[{"embeddable":true,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/comments?post=11140"}],"version-history":[{"count":9,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/posts\/11140\/revisions"}],"predecessor-version":[{"id":11155,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/posts\/11140\/revisions\/11155"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/media\/11148"}],"wp:attachment":[{"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/media?parent=11140"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/categories?post=11140"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/canamek.com\/es\/wp-json\/wp\/v2\/tags?post=11140"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}