WSJM – September 28, 2005 Fall Boron Applications
This is Al Gaus the Berrien County Extension Educator for fruit and ornamentals reporting from the Berrien County MSU Extension Office. Because of this past summer’s dry conditions, fruit growers may want to make a fall boron application. Mark Longstroth wrote about this in the September 6th Fruit Crop Advisory Team Alert. I will present most of that information here and include some other comments as well.
According to Mark, we most often see boron deficiencies like poor growth, tip death, corky tissue in the flesh of the fruit, cracking of the fruit, and poor fruit set in light sandy soils. Many of these symptoms are due to the fact that boron is not very soluble in water and so does not quickly move to the growing points.
The common sources of boron are Borax, Borate-46, Borate-65, and Solubor.
Typical ground applications are 1 to 1˝ pounds of boron per acre for apples and pears and ˝ to 1.0 pound for cherries. Peaches normally only receive ˝ pound. At this late date, ground applications will not allow the trees to absorb enough boron to do any good.
Fall foliar application of boron allows growers to get boron into next year’s flower buds where it will do the most good. Boron needs to be put on while the leaves are still active. Normally we do not advise applying boron unless leaf samples indicate that levels are deficient, but late season foliar sprays often result in increased fruit set without increasing foliar boron levels. Use no more that ˝ pound of actual boron per acre for these late season sprays. Even a small amount of boron now, should allow your trees to produce healthy flowers and pollen for bloom next spring. If you had a lot of deficiency symptoms this past year on apples, you may want to apply up to 1 pound of boron. One note of caution, peaches are very sensitive to excess boron and you really should only apply it to peaches if a leaf analysis indicates a need.
That is all for today, this has been Al Gaus for Berrien County MSU extension.