Stoller Enterprises, Ltd. Logo

Problem:

Many of our tree crops lack bud formation for flowers. This is particularly true on older trees that have vigorous shoot growth. Many times these trees have been planted on vigorous root stock. Each year, as the trees tend to vegetate more, the lack of flower buds and flowers become less and less.

Explanation:

Whenever a tree crop has vigorous shoot growth accompanied by long internode spacing, this is a clear indication that the growth of this tree is dominated by gibberellic acid. The gibberellic acid tends to cause more rapid leaf unfolding and apical meristem growth. This, in turn, causes the auxin that is produced at the shoot growth to rapidly move towards the roots.

When one observes tree growth, this is easily noticed by the tree limb that sticks straight upward (vertical growth) has fewer flowers. There is more of a tendency to have adequate flowers on the tree limbs that grow horizontally. This is due to the fact that auxin transport occurs more rapidly by gravitational force. Therefore the upright limbs transport auxin more rapidly than the horizontal limbs.

This rapid transport of auxin causes a hormone imbalance in the buds. The more rapid that this hormone moves from the growing tips down toward the roots, the greater tendency of the buds to stay dormant.

In order to encourage more flowering, the dominance of gibberellic acid must be decreased. Also, the amount of auxin in a dormant bud must be more properly balanced so that the bud will come out of dormancy to form a flower.

When these conditions exist, it is necessary to either tie down the tree limbs or foliar spray a product which will bring the vigorously growing tree back into hormone balance.

Prescription:

The application of 2 quarts per acre of Load will accomplish the above purpose. It should be foliar applied to any tree with vigorous growth approximately 2 weeks before anticipated bud swell. This should cause a hormonal shift in a tree so that the buds will tend to come out of dormancy and set flowers.

The same principal applies to annual crops that have difficulty setting flowers. It will also apply to annual crops that have vigorous shoot growth before the normal period of flowering. This would apply to such crops as soybeans, canola, tomatoes, or any other multiple fruiting crop where excessive nitrogen has been used or growing conditions are conductive to rapid vegetative growth.
On non-tree crops, the increase of budding and flowering may be accomplished by foliar application of only 1 quart per acre of Load.
Buds can be forced out of any plant during the reproductive stage of growth. In order to maximize the value of this foliar treatment, however, it should be applied just before the bud swell period on any crop.
J/JHS Articles/PEP – Lack of Flowers 031407 bc