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Table 3.3. Nutrient Recommendations for Tree Fruit Production 1,2,3,4,5
(In the absence of soil tests, use recommendations listed under medium phosphorus and medium potassium.)
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1Recommendations in this table were developed for spreading the total fertilizer requirement in drip area under trees. When fertilizer is broadcast over
more area than is occupied by drip area of trees, increase fertilizer rate so that the approximate rates recommended in this table will be applied under
drip area of trees. For example, if drip area of trees occupies 50 percent of the land area, then multiply rates recommended in table by number of trees
per acre and then double this rate to determine the rate per acre for broadcast application.
2Mature, standard-size apple trees require .5 to 1.5 pounds of nitrogen (N) per year per tree. Dwarf apple trees require .25 to .75 pound of nitrogen (N) per
year per tree. Pear trees should receive less nitrogen than apple trees because of fire blight problems. Mature peach, nectarine, cherry, and plum trees
require .5 to 1 pound of nitrogen (N) per year per tree. Nitrogen needs of tree fruits depend on variety, rootstock, tree vigor, soil type and fertility level,
and pruning and weed control practices employed. Apply nitrogen or mixed fertilizers on sandy loam or loamy sand soils 1 month before bloom.
Nitrogen or mixed fertilizers may be applied earlier on loam and silt loam soils. Heavily pruned trees need considerably less nitrogen than moderately
pruned trees.
3Lime soils to a pH of 6.0 to 6.5. Apply 30 and 15 pounds of magnesium (Mg) per acre in mixed fertilizer on soils very low and low in magnesium,
respectively, where lime is not needed.
4Broadcast 1 to 2 pounds of actual boron (B) per acre of mature apple trees that have been diagnosed to be boron deficient. This is in addition to boron
sprays recommended for apples. Approximate conversion factors to convert elemental boron (B) to different boron sources: boron (B) x 9 = borax
(11.36%B); boron (B) x 6.7 = fertilizer borate-48 (14.91%B); boron (B) x 4.7 = fertilizer borate-68 (21.13%B); and boron (B) x 4.9 = Solubor (20.5%B).
5For dwarf trees, use only 50 percent of the amounts of plant nutrients (N,P2O5,K20) recommended in table.
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How to Determine Nutritional Needs of
Trees
Fruittree growers must make an annual judgment
regarding the nutritional status of their trees. They must
decide whether to continue with the past year's program
or modify it in some manner to try to improve the growth
of their trees or the quality of the fruit produced. Soil
analysis can be used to evaluate the acidity and fertility
conditions of the soil before the growing season. Plant
analysis can be used to evaluate the nutritional status of
the trees during the growing seasons. Wise growers will
use both of these diagnostic tools along with a critical
evaluation of their own notes made during the previous
growing season in arriving at a decision concerning the
future lime and fertilizer needs of their trees.
Leaf tissue analysishas been widely used for many
years to detect and evaluate tree fruit responses to various
cultural practices and to identify apparent nutritional
disorders. The nutritional status of fruit trees can best be
diagnosed from analysis of leaf samples taken during the
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period of July 15 to August 15. Foliar nutrition changes
throughout the season, so for consistency, it is not wise
to interpret the results of leaf analyses made at different
times of the year.
This information may be used as a guide in making
changes in lime and fertilizer programs to better meet
nutritional requirements. Interpretation of leaf tissue
analysis data involves two separate and distinct functions:
(1) Decisions regarding which nutrient are causing an
unwanted response and (2) Decisions regarding treatments
necessary to improve response. These functions require
that the person evaluating the analytical results have a
thorough knowledge of the ranges in leaf concentration
values of tree fruits and be able to interpret the results into
desirable treatment changes, if needed.
A leaf analysis program is offered to fruit growers
through the NJ Tree Fruit IPM program. Growers who
want to use this service should contact their county fruit
extension agent or IPM agent in June of each year to
review what blocks are to be sampled. See the foliar
nutrition section under apples.
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