Last spring’s freeze means fruit growers must prune more, split fertilizer applications
COLUMBIA, Mo. – The unprecedented freeze of spring 2007 will affect fruit harvested this year, requiring more pruning and multiple fertilizer applications, said a University of Missouri fruit specialist.
“When temperatures plummeted in April after a very warm March, many growers had already applied fertilizer," said Michele Warmund.
“With the loss of fruit buds and fruit, nutrients normally diverted to developing crop became available for producing more vegetative shoots and leaves. This means fruit trees will require more hours of pruning this season,” she said.
First, remove dead and diseased wood. Next, remove unproductive branches and those that shade other fruit-bearing shoots to ensure sustained fruit production.
Thinning fruit will be important on peach and apple trees to balance fruit production and vegetative growth.
“This should be done as early as possible when the fruit is the size of a dime,” Warmund said.
Strip off all small fruitlets from peach trees, leaving 10 inches between each fruit. Peach branches often break when bearing too much fruit.
Barring erratic weather, apple trees should have a heavy crop load this year. Splitting the total amount of recommended fertilizer into two applications ? before bloom and after fruit set ? will sustain growth and prevent nitrogen leaching if applied as ammonium nitrate.
Multiple fertilizer applications will give producers the option to stop fertilizing if another catastrophic frost or freeze occurs, Warmund said.
Growers may face a greater incidence of pests this growing season due to reduced chemical applications or spraying last year. Uncontrolled pests from last year may increase pest populations this year, she said.
Diseases, such as fire blight on apple and pear trees and canker development in peach trees, may be worse this year as a result of last year’s freeze, Warmund said.