Nutrient deficiencies or excesses usually cause symptoms that are fairly indicative of problems with specific nutrients. Some nutrient disorders can be diagnosed by inspecting plants if you are familiar with symptoms. Unfortunately, incorrect diagnoses are common because the “classic” symptoms for deficiencies or excesses of some elements are similar and symptoms may vary in the field. Diagnoses are further complicated when crops are deficient in more than one element at the same time. A limitation of managing apple nutrition based on symptoms and plant tree appearance is that symptoms indicate a problem already exists—reductions in growth, yield or fruit quality may have already occurred. The goal in fertilizing is to avoid nutritional problems. Symptoms of the nutrient disorders commonly seen in Michigan fruit plantings are described in “Apple Nutrition” by Eric Hanson, MSU Department of Horticulture.
For a list of apple varieties with pictures, see the 2013 Apple Variety Showcase.
See our pollination page for information on apple pollination, pollinators, and pesticide use.
See the apple growth stages to quickly communicate the stage of development of the apple.
- PGRs and Thinning Strategies - Thinning is the most difficult and important practice, yet necessary for a grower to perform each year. Making a mistake will compromise both this and next year’s crop, but today with a more scientific approach to thinning, we can achieve successful and consistent annual croploads.
- Predicting Fruitset 2014 - This spreadsheet tool allows growers to evaluate ongoing fruitset and helps to access the effectiveness of their chemical thinning applications. Read more about how to use the Predicting Fruitset spreadsheet.