Four
of the critical stages of high nutrient demand for fruit trees are pollination,
early development, mid to late season, and late season/postharvest. During
these times, growers should be sure to maintain healthy fertilization levels.
Here are some tips during each stage of fruit production.
Stage 1: Pollination
Fertilizing for fruit set actually starts the season before during bud development.
This year, you’ll feed the buds from the prior season for good fruit set for
this season.
Fertilization
during bud development is important because you can always thin fruit off, but
you can’t create blossoms and fruit set if you don’t have it at the beginning,
according to Agro Culture Liquid fertilizer’s Dr. B. Levene.
Boron
is of critical importance during pollination and early fruit set. Many growers
apply a foliar boron spray, particularly during early bloom. Foliar
applications are the most efficient method of uptake and a foliar spray applies
nutrient right where it needs to be – on the buds themselves. The buds are a
small target, so growers don’t need much. In most cases, only a pound or two of
boron per acre per season would be needed.
Stage 2: Early Development
Early development is largely about nitrogen and phosphorus, applied to
produce a good canopy and for the energy to get and hold fruit set.
Many different types of application are used during this stage. Some growers
use a traditional dry spreader fertilizer and broadcast the fertilizer on the
floor of the orchard. Others will band dry fertilizer beside trees or liquid
fertilizer under the canopy, and still others inject through irrigation.
Overall,
fertilizer rates will be based on what’s appropriate for the age of the tree
and the results of a soil test. Applying higher rates on more mature trees and
lower rates on younger trees is part of using fertilizer responsibly, Levene
says.
Stage 3: Mid To Late Season
Calcium
and potassium are the nutrients to monitor mid to late season. Every variety
will need more potassium during this time.
Foliar
applications are the way to fine tune a crop, fill in certain growth stages or
deal with a dry period of little water uptake, but start with the soil to get
the right balance. As trees will also be setting buds for next season during
this phase, micronutrients can be important to apply at this time.
Stage 4: Late Season/Post Harvest
Most of the fruit varieties will have a fair bit of growing to do, even into
the late season. For these, maintaining insecticide and fungicide applications,
even after harvest, will maintain leaves as long as possible and give trees
more energy going into winter.
Please, refer to the 2015 Integrated Orchard Management
Guide for Commercial Apples in the Southeast and the 2015 Southeastern Peach,
Nectarine and Plum Pest Management and Culture Guide for more specific details on apple and peach nutrition scheduling:
http://entomology.ces.ncsu.edu/wp-content/uploads/2014/02/2015-ORCHARD-GUIDE-final-revised.pdf
www.ent.uga.edu/peach/PeachGuide.pdf
Elina Coneva, Fruit Specialist, ACES