Definition - What does Biennial Bearing mean?
Biennial bearing is a term used to refer to fruit, or crop-bearing, trees that produce an above average crop one year, while producing a below average crop the following year. Biennial bearing can be a result of many different factors, including but not limited to: environment, lack of nutrients, and lack of water. Several different actions can be taken to prevent biennial bearing. However, once a tree begins biennial bearing, the process can be difficult to correct.
Biennial bearing can also be known as alternate bearing.
MaximumYield explains Biennial Bearing
Biennial bearing is more common in fruit crops like apples, pears, and avocados. Some nut trees like pistachios can also be affected by biennial bearing. Biennial bearing is most often caused by trees that do not have sufficient water, or have been starved of nutrients for an extended period of time. Should this occur, trees will be unable to produce a heavy crop one year, and will typically over produce flower buds the following year. This cycle will continue until it is corrected.
Although biennial bearing is not easily corrected, there are several different methods that can potentially solve the problem. One method is to thin the fruit buds. The use of this method requires removing fruit buds from the tree in early spring of a “heavy-crop” year. This encourages the tree to produce an average crop while allowing it to have the resources to produce a crop the following year. Another method is to thin, or remove, young fruits a tree has grown. Although this method is less effective than thinning fruit buds, it can increase the size of the remaining fruit.
To ensure trees will not fall into a biennial bearing cycle, it is best that the tree receives adequate water and nutrients. This can be accomplished by fertilizing trees in early spring, keeping them well watered during dry seasons, and ensuring the area around a tree is kept free of weeds.