Alternate bearing fruit trees

As we are enjoying Spring and seeing the buds and flowers appear on fruit trees, Alternate bearing is a topic you will want to spend a few minutes to learn about.

Alternate bearing can be defined as the phenomenon where some crops will produce more fruit than they normally do, only to have the amount of production decrease for several years after that. This cycle is normal among certain tree fruits, including apples and pears. 

It is important to understand what causes it because alternate-year fruiting can result in reduced yield and quality, increased risk of pest damage, and lower levels of absorbed nutrients.

It is important to understand what causes it because alternate-year fruiting can result in reduced yield and quality, increased risk of pest damage, lower levels of absorbed nutrients.

In alternate bearing, trees will produce a large crop one year and then a small crop the next year. Alternate bearing causes fruit to be borne only every other year on some fruiting plants such as apple or citrus trees. In alternate-bearing alternate seasons, the production of fruits occurs after long intervals.

Biennial fruit trees alternate bearing results in a biennial fruiting pattern, alternate bearing occurs only every other year, and alternate bearing citrus fruit is borne during the main growing season and alternate years.

The cause of biennial bearing is not completely known although factors such as diseases, nutritional imbalances, water deficits, pollination problems, genetics, pruning methods used throughout several seasons are thought to play a role in this phenomenon.

Some apple varieties are more prone to alternate bearing than others. If a young apple tree experiences very little nitrogen in its first few years, it will never be able to support good fruit on that branch. The following year it may then respond to an increase in nitrogen by producing more fruit than usual. However. the increased production is only temporary and over time the tree becomes unbalanced with too much vigor on one side of the tree and too little vigor on the other side. The imbalance causes a reduction in crop load which results in alternating strong years.

When an apple tree is in its biennial period of bearing fruit, not only will production be low but there may also be leaf drop during the off years. This does not necessarily mean that all trees grown in containers will alternate bear; however, it is important to note this characteristic when deciding whether or not to grow fruit trees in pots. For example, if you had an apple tree growing in a container for four seasons and it produced very little fruit during the second year then you should look into replacing it with another type of ornamental plant because chances are high that the same thing will happen next season.

Alternate bearing causes many problems throughout the lifetime of fruit trees. It causes reduced crop quantity, causes lack of uniformity in size and causes poor or misshapen fruit.  Alternate bearing causes severe loss of income to commercial growers due to these factors and missed expectations from homeowners.

If you need help with your fruit trees, our Plant Healthcare Services department would be happy to help. Our professional staff can help with tree disease diagnosis, recommendation, treatment, fertilization, pruning and planting. 

You can trust the experts at Acorn Arborists to be both thorough and honest in their inspection of your trees. Ready to schedule a tree inspection or just want to know more? Use our contact form or give them a call at 916-717-8733.