Alternate Year Bearing

Problem:

Perennial trees, vines, and bushes will have a large crop of fruit during one year and the next year the crop of fruit is smaller. This has been normally followed by a larger crop of fruit the following year. The sequence of large yields and then smaller yields are very common to many of our perennial fruiting plants.

Explanation:

During the year when a plant has a very high yield of fruit, this heavy fruit yield will reduce all the photosynthates (sugar) that is stored in the woody tissue. This causes a lack of food for new shoot growth and new bud primordia for next year's crop. Many of the bud primorida will starve to death for the lack of food that is stored in the woody tissue.

Photosynthates sugars are synthesized in the leaves. They are then transferred from the leaves to the woody tissue of the plant.  The more photosynthesis that occurs in the leaves and the greater amount of transfer of these sugars to the woody tissue reserves, the more food will be available for the developing fruit, new shoot growth, new root growth, and lastly, the developing buds for next year's crop.

Therefore, it is extremely necessary for the leaves to increase both the manufacturing of photosynthates (sugar) and the transfer of these photosynthates from the leaves to the reserves that are stored in the woody tissue.

The number of fruit will depend upon the number of bud primordia which are formed in the plant during the previous year. These bud primordia must have adequate food in order to develop and become the buds for the following year's crop.

When the plant has a heavy fruit load year the fruit uses most of the sugar reserves in the woody tissue and in order to grow and develop. They are the strongest sink in the plant. Therefore, during heavy fruit load years, one sees shorter shoot growth. This is easily observed. Therefore, one can conclude that the developing fruit, on a heavy year, will also use sugar reserves that are meant for new bud primorida growth for the following year's crop.

One can conclude that on a heavy fruit load year the fruit uses most of the sugar reserves in the woody tissue and during their development, the bud primordia does not get enough fruit, and therefore many of them will starve.

Prescription:

The application of Sugar Mover to the whole plant every 10 days will cause the leaves to synthesize more photosynthates (sugar) and will cause the leaves to transfer more of these to the sugar reserves in the woody tissue of the plant.

This application should begin immediately after fruit set. It should be continued on a 10 day interval until harvest. If this is done in consisten manner, it will help create the sugar reserves in the woody tissue so that there is adequate food for the large developing crop, shoot growth, root growth, and the developing buds for next year's crop.

If the above treatment is followed, the bud primorida should remain healthy every year. The amount of alternate year bearing should be greatly reduced. One may then have more consisten yields every year.

J/JHS Articles/PEP - Alternate Year Bearing 030107 bc