Minimizing Inputs for Minimizing Inputs for Optimal Floriculture Optimal Floriculture

and Nursery Crop Pest and Nursery Crop Pest ManagementManagement

Kevin M. Heinz & Fred DaviesKevin M. Heinz & Fred DaviesDepartments of Entomology & Horticultural SciencesDepartments of Entomology & Horticultural Sciences

Texas A&M University, College StationTexas A&M University, College Station

Floral and Nursery Crop Research InitiativeFloral and Nursery Crop Research InitiativeResearchers MeetingResearchers Meeting

March 25, 2003March 25, 2003

Project OverviewProject Overview

Fit relative to entire programFit relative to entire program

Project accomplishments - EntomologyProject accomplishments - Entomology

TangiblesTangibles

Future directionsFuture directions

Project PositionProject Position

AFEAFEIPMIPM

PESPPESPSamplingSampling

NRINRIThrips BCThrips BC

ARSARSInputsInputs

80% of Texans reside 80% of Texans reside in urban areasin urban areas

Urban and suburban Urban and suburban areas compete for areas compete for limited resource - limited resource - WATERWATER

Need for reduced Need for reduced inputs in an arid stateinputs in an arid state

Texas AgricultureTexas Agriculture

Texas Problems?Texas Problems?

• The Texas Department of Agriculture issued The Texas Department of Agriculture issued 1331 stop sale orders to Texas greenhouse 1331 stop sale orders to Texas greenhouse and nursery growers (1996 – 2000)and nursery growers (1996 – 2000)

• 98.8% were issued for the occurrence of pest 98.8% were issued for the occurrence of pest insects.insects.

Texas Department of Agriculture - Unpublished

Inputs and Pest Inputs and Pest ManagementManagement

Reducing inputs will reduce plant qualityReducing inputs will reduce plant quality

Reducing inputs will reduce insect Reducing inputs will reduce insect problemsproblems

At high inputs, prophylactic applications At high inputs, prophylactic applications of insecticidesof insecticides

Reduce inputs, reduce insecticides, Reduce inputs, reduce insecticides, retain plant qualityretain plant quality

Inputs and Pest Inputs and Pest ManagementManagement

Chrysanthemum as modelChrysanthemum as model

Nitrogen as first input measureNitrogen as first input measure

Study three insects: aphids, thrips, Study three insects: aphids, thrips, leafminersleafminers

Assess population dynamics, pesticide Assess population dynamics, pesticide applications, and plant quality at varying applications, and plant quality at varying input levelsinput levels

Inputs and Pest Inputs and Pest ManagementManagement

Heinz - EntomologyHeinz - Entomology

Davies - HorticultureDavies - Horticulture

BogrBográán – Plant Pathology (& extension)n – Plant Pathology (& extension)

Project OverviewProject Overview

Fit relative to entire programFit relative to entire program

Project accomplishments – EntomologyProject accomplishments – EntomologyNovember 2000 – March 2003November 2000 – March 2003

TangiblesTangibles

Future directionsFuture directions

Aphid Population GrowthAphid Population Growth

0 19.83 296.50

19 53.50 472.17

38 209.17 616.50

75 570.00 833.33

375 803.17 868.33

Nitrogenppm N

ChamberN = 6

GreenhouseN = 10

Aphid Population GrowthAphid Population Growth

Thrips Population GrowthThrips Population Growth

0 19.50 35.80

19 179.33

38 181.67 71.80

75 268.00 137.10

375 449.00 352.10

Nitrogenppm N

ChamberN = 6

GreenhouseN = 10

Insecticide ApplicationsInsecticide Applications

0 0.80 0.80 0.80

75 1.20 1.80 1.80

375 1.20 2.80 3.00

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Thrips DensitiesThrips Densities

0 18.20 8.20 11.40 8.60

75 17.40 20.00 19.60 25.00

375 6.60 24.00 22.60 72.00

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Proportion Flower DamageProportion Flower Damage

0 0.55 0.40 0.64 0.20

75 0.20 0.39 0.21 0.17

375 0.22 0.22 0.13 0.32

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Plant HeightPlant Height

0 16.26 16.26 15.98 15.16

75 21.76 22.92 21.56 20.90

375 20.64 23.36 21.56 22.24

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Leaves Per PlantLeaves Per Plant

0 60.20 57.80 56.40 51.20

75 168.80 166.40 185.80 154.20

375 180.60 175.80 204.40 204.40

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Opened Flowers Per PlantOpened Flowers Per Plant

0 5.00 5.40 5.60 4.40

75 23.40 24.60 23.80 21.40

375 25.80 26.60 25.00 29.40

Nitrogenppm N

ConserveN = 5

OrtheneN = 5

TalstarN = 5

ControlN = 5

Project OverviewProject Overview

Fit relative to entire programFit relative to entire program

Project accomplishments - EntomologyProject accomplishments - Entomology

TangiblesTangibles

Future directionsFuture directions

TangiblesTangibles

Demonstrate capability to produce quality Demonstrate capability to produce quality chrysanthemums with reduced inputs.chrysanthemums with reduced inputs.

Preparing students for the industry (Karol Preparing students for the industry (Karol Burns, Carlos BogrBurns, Carlos Bográn, undergraduate án, undergraduate interns)interns)

Growth in TAES/TCE faculty with Growth in TAES/TCE faculty with ornamentals emphasis (Carlos Bogrornamentals emphasis (Carlos Bográn, án, Scott Ludwig)Scott Ludwig)

Fertility Affects on Chrysanthemum × Aphid Fertility Affects on Chrysanthemum × Aphid Interactions: Influences on Plant Growth, Interactions: Influences on Plant Growth, Photosynthesis, Ethylene Evolution and Photosynthesis, Ethylene Evolution and

Herbivore AbundanceHerbivore Abundance

Fred DaviesFred DaviesChuanjiu HeChuanjiu He

Amanda ChauAmanda ChauKevin HeinzKevin Heinz

Host Plant/CropHost Plant/Crop: Greenhouse mum ‘Charm’ : Greenhouse mum ‘Charm’ Biotic StressBiotic Stress:: Aphids Aphids

Abiotic Stress:Abiotic Stress: Fertility Fertility

Objectives:Objectives: Determining fertility and aphid influenceDetermining fertility and aphid influence on plant growth & development and on plant growth & development and herbivore (NO PESTICIDE STRESSES herbivore (NO PESTICIDE STRESSES ADDED) ADDED)

Treatments:Treatments: 2 2 aphid levels x 5 fertility levels = 10 trts. aphid levels x 5 fertility levels = 10 trts.

Bottom Middle Apical Quick Rinse of Aphid Exudate

Tot

al P

lan

t D

M (

g)T

otal

Pla

nt

DM

(g)

Fertility Level (ppm N)Fertility Level (ppm N)0 19 38 75 375

0

10

20

30

40

50

No Aphids

Aphids

0

1

2

3

No Aphids

Aphids

Tot

al B

ud

DM

(g)

Tot

al B

ud

DM

(g)

00 19 19 38 38 75 75 375 375

Fertility Level (ppm N)Fertility Level (ppm N)

Lea

f D

M (

g)L

eaf

DM

(g)

0 19 38 75 3750

5

10

15

20

No Aphids

Aphids

Fertility Level (ppm N)Fertility Level (ppm N)

Tot

al L

eaf

Are

a (c

mT

otal

Lea

f A

rea

(cm

22 ))

00 19 19 38 38 75 75 375 375

Fertility Level (ppm N)Fertility Level (ppm N)

0

500

1000

1500

2000

2500

3000

3500

No Aphids

Aphids

Sp

ecif

ic L

eaf

Are

a (c

mS

pec

ific

Lea

f A

rea

(cm

22 g g-1-1

))

Fertility Level (ppm N)Fertility Level (ppm N)

0 19 38 75 3750

50

100

150

200No Aphids

Aphids

Eth

ylen

e P

rod

uct

ion

Rat

eE

thyl

ene

Pro

du

ctio

n R

ate

(pm

ol g

(pm

ol g

-1-1 F

W h

FW

h-1-1))

BudsBuds Young Phys. Mat Old Young Phys. Mat Old LeafLeaf LeafLeaf Leaf Leaf

0

100

200

300

400

No Aphids

Aphids

Pn

(P

n (

mol

CO

mol

CO

22 m m

-2-2 s s

-1-1))

Young Phys. Mat OldYoung Phys. Mat Old LeafLeaf Leaf Leaf Leaf Leaf

0

5

10

15

20

No Aphids

Aphids

N (

%)

N (

%)

Fertility Level (ppm N)Fertility Level (ppm N)

0

0.5

1

1.5

2

2.5

3

3.5

No Aphids

Aphids

00 19 19 38 38 75 75 375 375

Phys. Mat LeavesPhys. Mat Leaves

0

0.5

1

1.5

2

2.5

3

3.5No Aphids

AphidsYoung LeavesYoung Leaves

0 19 38 75 3750

500

1000

1500

2000

Young Leaf

Phys. Mature Leaf

Old Leaf

Fertility Level (ppm N)

Ap

hid

s N

o.

SummarySummary:: •REDUCED PLANT QUALITY: Aphids depressed plant REDUCED PLANT QUALITY: Aphids depressed plant vegetative and reproductive growth, and altered carbohydrate vegetative and reproductive growth, and altered carbohydrate partitioning at high fertility. partitioning at high fertility.

•Aphid inoculated (Aphid inoculated (AIAI) plants at high fertility had increased ) plants at high fertility had increased specific leaf area [(SLA), i.e. thinner leaves] and greater leaf area specific leaf area [(SLA), i.e. thinner leaves] and greater leaf area than aphid-free (than aphid-free (NonAINonAI) plants. ) plants.

•Aphids caused greater ethylene production in reproductive buds Aphids caused greater ethylene production in reproductive buds and young leaves of high fertility plants, but had no effect on and young leaves of high fertility plants, but had no effect on ethylene evolution in physiologically mature or older - basal ethylene evolution in physiologically mature or older - basal leaves.leaves.

Summary (con.)Summary (con.)::

• AIAI plants had lower leaf N than plants had lower leaf N than NonAINonAI treatments. treatments.

•Aphids reduced photosynthesis in young leaves of high fertility Aphids reduced photosynthesis in young leaves of high fertility plants, whereas physiologically mature and older leaves were plants, whereas physiologically mature and older leaves were unaffected. unaffected.

• Aphid abundance was greatest at high fertility. Aphid abundance was greatest at high fertility.

• A higher proportion of aphids were observed in physiologically A higher proportion of aphids were observed in physiologically mature and older leaves at low fertility, whereas at high fertility mature and older leaves at low fertility, whereas at high fertility young leaves had 33% more aphids than older, basal leaves. young leaves had 33% more aphids than older, basal leaves.

Application to StakeholdersApplication to Stakeholders

•The morphology and physiological status of chrysanthemum The morphology and physiological status of chrysanthemum determines its susceptibility to aphids. determines its susceptibility to aphids.

•Aphids increase ethylene, decrease net photosynthesis, and Aphids increase ethylene, decrease net photosynthesis, and decrease carbon allocation to leaves and reproductive structures, decrease carbon allocation to leaves and reproductive structures, particularly at higher fertility.particularly at higher fertility.

•While growing plants under deficient fertility levels is not a While growing plants under deficient fertility levels is not a satisfactory strategy for reducing insect pests, reducing fertility satisfactory strategy for reducing insect pests, reducing fertility and pesticide levels and producing healthier, less stress and pesticide levels and producing healthier, less stress susceptible plants is a realistic endeavor for best management susceptible plants is a realistic endeavor for best management practices (BMP) and IPM systems.practices (BMP) and IPM systems.

Experiment Harvest

FutureFuture

One More Insect Herbivore - Leafminers.One More Insect Herbivore - Leafminers.

Increase Resolution of Reduced Inputs.Increase Resolution of Reduced Inputs.

IPM approach to include biological control.IPM approach to include biological control.

Demonstrations in Commercial Greenhouses.Demonstrations in Commercial Greenhouses.

Incorporation of Plant Pathogen Management.Incorporation of Plant Pathogen Management.

Inclusion of Water and Water Inclusion of Water and Water × Nutrient × Nutrient Stresses.Stresses.