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