Foliar Nutrient Application Update: Opportunities & Solutions Scott Johnson Patrick Brown UC Davis Dept of Plant Sciences
Foliar Nutrient
Application Update:
Opportunities & Solutions
Scott Johnson
Patrick Brown
UC Davis
Dept of Plant Sciences
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
Zinc Materials
Basic Chemicals
• Zn sulfate
• Zn oxide
• Zn carbonate
• Zn chloride
• Zn oxysulfate
• Zn nitrate
Chelates & Complexes
• EDTA
• Lignosulfonate
• Amino acid
• Sugar
• Citric acid
• Fulvic acid, humic acid
UTCUTC
Treated
Treated
Leaf Area of Individual Leaves
0.0
3.0
6.0
9.0
12.0
-10 0 10 20
Node from Time of Treatment
Le
af
Are
a (
cm
2)
Control
Sulfate
Nitrate
Carbohy
Oxide
Leaf Area of Individual Leaves
0.0
3.0
6.0
9.0
12.0
-10 0 10 20
Node from Time of Treatment
Le
af
Are
a (
cm
2)
Control
Sulfate
Nitrate
Carbohy
Oxide
Comparing Zinc Formulations
Most Effective = Sulfate – 36%
Polyamine
Nitrate
Carbohydrate
Less Effective = EDTA
Leonardite
Neutral Zn – 52%
ZnO Suspensions
Zn-EDTA
Comparing Zinc Formulations
Most Effective = Sulfate – 36%
Polyamine
Nitrate
Carbohydrate
Less Effective = EDTA
Leonardite
Neutral Zn – 52%
ZnO Suspensions
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
Labeled 68Zn Sulfate vs. 68Zn Oxide
Applied to Dormant Nursery Trees
68Zn
Uptake
(% of
applied)
0
0.5
1.0
1.5
Control Zn Sulfate Zn Oxide
c
a
b
Treatment
Nursery Trees in Pots - Application to Dormant Shoots68ZnSO4 vs. 68ZnO - % of Applied Taken Up
%
Uptake
0
1
2
3
UTC 68ZnSO468ZnO
d
a
b
cc
JanuaryNovember
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
4. Longer time on leaf or shoot =
Better uptake
Treatment - ppm Zinc
Nursery Trees in Pots - Fall Foliar 68ZnSO4
Rates and Timing - 68Zn in Plant
68Zn
From
Fertilizer
(mg)
0
20
40
60
UTC 1,000 2,000 5,000
Oct 24 Nov 16
d
bc
aa
c
b
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
4. Longer time on leaf or shoot =
Better uptake
5. Optimum rate
Treatment - ppm Zinc
Peach Seedlings - 68ZnSO4 Rate68Zn in Untreated Plant Organs
68Zn
From
Fertilizer
(mg)
0
1
2
3
4
UTC 100 200 400 1000 5000
ede
d
c
b
a
Treatment - ppm Zinc
Peach Seedlings - 68ZnSO4 Rate68Zn Taken Up by Plant as % of Applied
%
Uptake
0
1
2
3
UTC 100 200 400 1000 5000
d
b b
a
b
c
1 3 5
Control
Neutral -52%
Fulvic
Sulfate
Lignosulfonate
A.A. Complex
EDTA
Nitrate
Leaf & Fruit Damage on Peach, Plum and Apricot Trees
Sprayed in April with Different Formulations of Zn at 1,000 ppm
0 2 4
Fruit damage
Leaf damage
Damage Rating
Foliar Nutrient Uptake Principles
Nitrogen & Zinc
1. Cuticle biology
2. Smaller molecules = Better uptake
3. More soluble materials = Better
uptake
4. Longer time on leaf or shoot =
Better uptake
5. Optimum rate
0
1
2
3
4
5
Roots Trunk Shoots New
Growth
%
of
Label
Zn
Applied
Roots Trunk Shoots
Dormant One month after Bloom
Recovery of Labelled 68Zn Sulfate Applied to
Leaves of One-Year-Old Peach Trees in the Fall
Treatment
Peach Seedlings - 68ZnSO4 vs 68ZnO68Zn in New Growth and Roots
68Zn
From
Fertilizer
(mg)
0
5
10
UTC ZnSO4 ZnO ZnSO4 + ZnO
d
b
c
a
5 Year Zinc
0.000
0.500
1.000
1.500
2.000
2.500
Nov
2002
USD / lb
Oct
2003
Sept
2004
Sept
2005
Sept
2006
Aug
2007
Nutrient Elements in Stone Fruit
NPKCaMgClS
FeMnZnBCuMo
%2.3-
1.0-
0.25--
60201518--
%2.6 - 3.00.1 - 0.3Over 1.2Over 1.0Over 0.25
--
Over 60Over 20Over 2020 - 80Over 4
-
%-----
0.3-
---
100--
%--
1.0-
0.25--
-2018254-
%2.3 - 2.80.1 - 0.3Over 1.1Over 1.0
Over 0.25--
-Over 20Over 1830 - 60Over 4
-
%-----
0.3-
---
80--
Deficient below
Optimum range
Toxic over
Deficient below
Optimum range
Toxic over
PEACHES AND NECTARINES
Level in leaves
PLUMS
p p m
Zn Sulfate
ZnO Suspension
Neutral Zn
Zn Ligno-Sulfonate
N Zn
Zn Metalosate
Zn EDTA
Zn Leonardite
Zn Fulvic
$0 10 20 30 40
10%
52%
40%
7%
9%
6.5%
5%
6.8%
36%
$17.01
$4.12
$7.55
$9.15
$12.88
$15.19
$16.51
$33.51
$2.22
Cost of Zinc Materials - October 2007