applied experiences focused on citrus nutrition and water

Applied experiences focused on citrus nutrition and water management for

mitigating HLBExperiencias aplicadas en la nutriciÓn

de cÍtricos y manejo de agua para mitigar del HLB

Davie Kadyampakeni

University of Florida

Citrus Research and Education Center

Lake Alfred, FL33850.

2o CIL, Quadalajara, Jalisco, Mexico 11 October, 2019

Outline

Status of HLB in FL: What we know now

Irrigation studies for managing HLB: Examples

Nutrition studies for managing HLB: Highlights

Summary

Acknowledgements

Current Status of HLB

• Citrus accounts for $10 billion in economic activity

• Pre-HLB 240 million boxes (10 billion tons)

• Current 80 million boxes (3.3 billion tons), about 67% reduction in

production

• Production costs up to $2100 per acre due to HLB

• Significant reduction in production area

• Declined tree performance, root loss and significant defoliation

Irrigation strategies for managing HLB• Preventative measures: HLB negative (healthy trees)

• Frequent irrigation (daily or multiple times a day) e.g. Citrus Under Cover Production System• Regulated deficit irrigation • Partial root zone dryingPlus Asian psyllid control

• Curative management of HLB positive trees (asymptomatic trees)• Daily irrigation plus Asian psyllid control• Managing pH to optimum levels for nutrient availability• Improved nutrition programs via fertigation

• Remediation/Management of HLB affected trees (symptomatic trees)• Daily irrigation plus Asian psyllid control• Managing pH to optimum levels for nutrient availability• Fertigation practices

Irrigation strategies for managing HLB

Field studies on irrigation conducted in:

• Irrigation studies at 3 sites: Ave Maria, Avon Park, Arcadia (2013-2014)

Comparison of Daily, IFAS (recommended by UF) and Intermediate Irrigation Schedules based on Florida Automated Weather Network (FAWN) evapotranspiration

• Advanced Citrus Production Systems (ACPS) studies:

Two Sites: Immokalee at UF/IFAS, SWFREC, and Lake Alfred (2008 to 2011)Comparison of drip and modified microsprinkler irrigation with grower

practices

• Greenhouse studies conducted at Immokalee, SWFREC (2014-2015)

Comparison of HLB vs non-HLB affected citrus

Irrigation studies

Water use of HLB affected trees in south west and central Florida

• Daily > Intermediate > IFAS irrigation scheduling

• Daily irrigation could help in managing HLB affected trees, reduce tree water stress

Irrigation studiesTotal available water (%) in southwest and central Florida

• Increasing TAW with depth, greater uptake in the top 6 inches.

• Greater TAW in in top 15 cm than lower 15-45 cm for Daily than Intermediate and IFAS irrigation schedule.

Irrigation treatment

Soil depth (cm)

Commercial site

Arcadia Avon Park Immokalee

Daily

0-15 68.9dc 80.7b 68.1bc

15-30 72.2c 58.7c 75.3b

30-45 98.2a 87.8a 97.9a

Intermediate

0-15 52.2fg 56.3cd 64.5c

15-30 58.9ef 61.4c 46.6d

30-45 98.8a 74.3b 42.3d

IFAS

0-15 48.1g 49.7d 46.6d

15-30 80.9b 50.4d 32.1e

30-45 62.3de 61.9c 69.3bc

ANOVA

Arcadia Avon Park Immokalee

Source of variation Pr > F Pr > F Pr > F

Irrigation treatment <.0001 <.0001 <.0001

Soil depth <.0001 <.0001 <.0001

Irrigation treatment x Soil depth <.0001 <.0001 0.0876

Irrigation studies in central and southwest Florida

Avon Park

Vol

umet

ric w

ater

con

tent

(m

3 m-3

)

0.00

0.02

0.04

0.06

0.08

0.10

0.12 IFAS

Intermediate

Daily

Immokalee

Soil depth (cm)

0-15 15-30 30-45

Vol

umet

ric w

ater

con

tent

(m

3 m-3

)

0.00

0.02

0.04

0.06

0.08

0.10

0.12 IFAS

Intermediate

Daily

ArcadiaV

olum

etric

wat

er c

onte

nt (

m3 m

-3)

0.00

0.02

0.04

0.06

0.08

0.10

0.12IFAS

Intermediate

Daily

Arcadia

0.10 0.15 0.20 0.25

Sap

flow

(g

m-2

h-1

)

18

20

22

24

26

28

30

Syx = 0.2794

P = 0.02

r2 = 0.999***

Y = 13.62 + 57.4x

Avon Park

0.04 0.06 0.08 0.10

Sap

flow

(g

m-2

h-1)

20

22

24

26

28

30

32

34

36

38

Syx = 0.5719

P = 0.0353

r2

= 0.999***

Y = 12.7 + 276.6x

Immokalee

Volumetric water content (m3 m

-3)

0.04 0.06 0.08 0.10 0.12 0.14

Sap

flow

(g

h-1 m

-2 h

-1)

5

10

15

20

25

30

35

40

45

Y = -27.5 + 534.3x

Syx = 1.523

P = 0.0488

r2= 0.994***

Moisture contents and significant relationships with sapflow

Water use of HLB affected trees in southwest Florida under greenhouse conditions

• 22 to 35% greater water use for Non-HLB affected trees

• Inter-season and annual variability in water use

• Comparable water use between varieties

Month -year ETo

(mm d-1)

ETc (mm d-1) ETc diff. (%)‡

Hamlin-Non HLB Hamlin-HLB

Jan-Jun-14 3.57 2.97 2.23 23.73

Jul-Dec-14 4.42 4.16 2.63 34.82

Jan-Jun-2015 3.38 4.08 2.83 29.82

Jun-Oct-15 3.73 4.94 3.18 35.20

Overall Average 3.79 4.00a** 2.69b** 30.75

Valencia-Non HLB Valencia-HLB

Jan-Jun-14 3.57 2.83 2.22 22.28

Jul-Dec-14 4.42 3.97 2.83 28.85

Jan-Jun-2015 3.38 3.85 2.69 30.98

Jun-Oct-15 3.73 4.79 3.56 26.42

Overall Average 3.79 3.82a** 2.80b** 26.99**

Citrus Crop Coefficients between HLB and Non-HLB affected Citrus Trees

• Patterns of Kc similar for HLB affected and non-affected trees

• Non-affected tree Kc similar to those found to field trees prior to greening

• Infected trees consistently with lower Kc

• 35.2% in 2014 and 20.8% in 2015

0

0.2

0.4

0.6

0.8

1

1.2

Dec-13 Feb-14 Apr-14 Jun-14 Aug-14 Oct-14 Dec-14

Cro

p C

oe

ffic

ien

t (K

c)

Date

Hamlin Hamlin - HLB Valencia Valencia - HLB IFAS

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Dec-14 Feb-15 Apr-15 May-15 Jul-15 Sep-15 Oct-15 Dec-15C

rop

Co

eff

icie

nt

(Kc)

Date

Hamlin Hamlin - HLB Valencia Valencia - HLB IFAS

Crop coefficient (Kc) for HLB affected trees in southwest Florida under greenhouse conditions

Nutrition studies for managing HLB: Highlights• Advanced Citrus Production Systems (ACPS) studies:

Two Sites: Immokalee at UF/IFAS, Immokalee, and Lake Alfred (2008 to 2011)

Comparison of drip and modified microsprinkler fertigationsystems with Conventional grower practices

Two ACPS systems: drip (DOHS) and microsprinkler (RM, MOHS), and conventional microsprinkler practice (CMP)

Leaf NPK concentration

ACPS Nutrition Studies

Fertigation practice

CMP DOHS MOHS

Lea

f co

nc.

(%)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

N

P

K

Leaf NPK conc. were in

optimum or high range.

CMP needs more fertilizer and

water per ha at 1 to 2.5 years than

ACPS (Schumann et al. 2010)

Nutrient efficiency (m3/kg N)

Fertilization method

CMP MOHS DOHS-S DOHS-C35

Eff

icie

ncy

(cu

bic

m/k

g N

)

0

10

20

30

40

50

60

After 1 year

After 2.5 years

N and P accumulation on Immokalee sandFertigation

methodCMP Drip RM CMP Drip RM

Tissue N (kg ha-1) P (kg ha-1)

Leaves 24.00 49.78 37.10 1.34 1.69 1.48

Fruits 22.40 15.78 29.98 2.68 1.03 2.28

Branches/trunk 20.70 28.38 26.44 4.76 3.80 4.22

Roots 11.60 20.82 20.20 2.85 2.98 2.96

Total 78.70 114.78 113.72 11.64 9.52 10.95

ACPS Nutrition Studies (2)

High N accumulation with ACPS than CMP but P

accumulation similar for all practices.


Leaf NPK concentration (%) determined in

June 2009 at Immokalee.

• Sufficient NPK concentrations.

• Drip OHS was effective in

enhancing N uptake compared with

the other two irrigation methods

studied.

• Leaf P concentration was high

(0.17-0.30%) in all treatments

• Leaf K concentration was within

optimum and high ranges (1.2-

2.4%) suggesting no significant

differences between ACPS and

Conventional method.


0

0.5

1

1.5

2

2.5

3

Irrigated Non-irrigated Irrigated Non-irrigated

Ammonium N Nitrate N

Con

cen

trati

on

(m

g/k

g)

Conventional practice Drip OHS Microsprinkler OHS

Ammonium and nitrate distribution in the irrigated and non-irrigated zone

• Greater inorganic

N in irrigated than

non-irrigated

zones

• Better N contents

in irrigated zones

of ACPS than

Conventional.


0

10

20

30

40

50

60

70

80

90

Co

nce

ntr

atio

n (

mg/

kg)

Mehlich 1 P Irrigated

Mehlich 1 P Non-irrigated

Soil P distribution in the irrigated and non-irrigated zones

• Greater P in

irrigated than non-

irrigated zones

• Soil P contents in

irrigated zones of

Drip greater than

Conventional.


Lateral ammonium-N (mg/kg) distribution in July 2010 at the Lake Alfred site using drip fertigation.

Cross-row (cm)

0 5 10 15 20 25 30

With

in ro

w (c

m)

0

5

10

15

20

25

30

0.4

0.5

0.6

0.7

0.8

0.9

D

T

Higher NPK conc.

in irrigated vs.

non-irrigated zones

of drip fertigation.

D=area below

dripper, T=tree


Mehlich 1 P (mg kg-1)

20 40 60 80 100 120 140 160

Depth

(cm

)

0

20

40

60

80

100

120

140

DOHS-Swingle

CMP

DOHS-C35

MOHS

Mehlich 1 P (mg kg-1)

0 10 20 30 40 50

Depth

(cm

)

0

20

40

60

80

100

120

140

CMP

DOHS

MOHS

Immokalee

Candler

Vertical P distribution at Immokalee and Lake

Alfred sites in 2010

Less P leaching with OHS than CMP in 2010.

High P at Lake Alfred than Immokalee


Canopy volume as a function of fertilization practice at the Lake Alfred site

ACPS fertigation

had greater tree size

than conventional

practice

Date

11/1/09 1/1/10 3/1/10 5/1/10 7/1/10

Can

opy

volu

me

(m3 )

0.0

0.5

1.0

1.5

2.0

2.5

DOHS-Swingle

CMP

MOHS

DOHS-C35


Lateral RLD (cm cm-3) distribution using CMP

Lateral RLD (cm cm-3) distribution using DOHS

Cross-row (cm)

0 10 20 30 40

With

in r

ow

(cm

)

0

5

10

15

20

25

30

0.07

0.08

0.09

0.10

0.11

MT

Cross-row (cm)

0 10 20 30 40

With

in r

ow

(cm

)

0

5

10

15

20

25

30

0.15

0.20

0.25

0.30 T

D

D

T=tree, M=microsprinkler

Roots uniformly distributed

around the tree

T=tree, D=dripper, Roots

concentrated below the

drippers

Positions in the irrigated zones of showed higher root density than non-irrigated zones

M=microsprinkler

T=tree

Cross-row (cm)

0 10 20 30 40

With

in r

ow

(cm

)

0

5

10

15

20

25

30

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

MT


Lateral root density (cm cm-3) distribution

using ACPS microsprinkler

Summary

Daily, frequent irrigation critical for improved tree performance, soil moisture distribution and water use.

HLB affected trees use 22 to 35% less water than the non-affected trees.

ACPS practices could be adapted to grower practices for vigorous tree growth, water use, greater root density and nutrient accumulation.

Acknowledgements

• Dr. Morgan, Dr. Schumann, Dr. Ebel, Dr. Hamido – University of Florida

• Grove/Orchard Space: • UF/IFAS SWFREC, Immokalee, FL

• Gapway Groves, Auburndale, FL

• Pacific Inc., Ave Maria, FL

• Orange Co, Arcadia, FL

• Ben Hill Griffin, Avon Park, FL

• Funding: Southwest FL WMD, FDACS, UF/IFAS

• Thanks to Mrs. Ana Villalpando and Dr. Medina for the invitation. Muchas Gracias!

Muchas gracias!!

applied experiences focused on citrus nutrition and water

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