Minimizing Inputs for Optimal Floriculture and Nursery Crop Pest Management

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Minimizing Inputs for Optimal Floriculture and
Nursery Crop Pest Management
Floral and Nursery Crop Research
Initiative Researchers Meeting March 25, 2003

• Kevin M. Heinz Fred Davies
• Departments of Entomology Horticultural
  Sciences
• Texas AM University, College Station

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Project Overview

• Fit relative to entire program
• Project accomplishments - Entomology
• Tangibles
• Future directions

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Project Position
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Texas Agriculture

• 80 of Texans reside in urban areas
• Urban and suburban areas compete for limited
  resource - WATER
• Need for reduced inputs in an arid state

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Texas Problems?

• The Texas Department of Agriculture issued 1331
  stop sale orders to Texas greenhouse and nursery
  growers (1996 2000)
• 98.8 were issued for the occurrence of pest
  insects.

Texas Department of Agriculture - Unpublished
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Inputs and Pest Management

• Reducing inputs will reduce plant quality
• Reducing inputs will reduce insect problems
• At high inputs, prophylactic applications of
  insecticides
• Reduce inputs, reduce insecticides, retain plant
  quality

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Inputs and Pest Management

• Chrysanthemum as model
• Nitrogen as first input measure
• Study three insects aphids, thrips, leafminers
• Assess population dynamics, pesticide
  applications, and plant quality at varying input
  levels

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Inputs and Pest Management

• Heinz - Entomology
• Davies - Horticulture
• Bográn Plant Pathology ( extension)

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Project Overview

• Fit relative to entire program
• Project accomplishments Entomology
• November 2000 March 2003
• Tangibles
• Future directions

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Aphid Population Growth
Nitrogen ppm N
Chamber N 6
Greenhouse N 10
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
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Aphid Population Growth
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Thrips Population Growth
Nitrogen ppm N
Chamber N 6
Greenhouse N 10
0 19.50 35.80 19 179.33 38 181.67 71.80 75 26
8.00 137.10 375 449.00 352.10
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Insecticide Applications
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
0 0.80 0.80 0.80 75 1.20 1.80 1.80 375 1.20 2
.80 3.00
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Thrips Densities
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
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
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Proportion Flower Damage
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
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
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Plant Height
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
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
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Leaves Per Plant
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
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
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Opened Flowers Per Plant
Orthene N 5
Talstar N 5
Nitrogen ppm N
Conserve N 5
Control N 5
0 5.00 5.40 5.60 4.40 75 23.40 24.60 23.80 21.4
0 375 25.80 26.60 25.00 29.40
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Project Overview

• Fit relative to entire program
• Project accomplishments - Entomology
• Tangibles
• Future directions

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Tangibles

• Demonstrate capability to produce quality
  chrysanthemums with reduced inputs.
• Preparing students for the industry (Karol Burns,
  Carlos Bográn, undergraduate interns)
• Growth in TAES/TCE faculty with ornamentals
  emphasis (Carlos Bográn, Scott Ludwig)

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Fertility Affects on Chrysanthemum Aphid
Interactions Influences on Plant Growth,
Photosynthesis, Ethylene Evolution and Herbivore
Abundance Fred Davies Chuanjiu He Amanda
Chau Kevin Heinz
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Host Plant/Crop Greenhouse mum Charm
Biotic Stress Aphids Abiotic Stress
Fertility Objectives Determining
fertility and aphid influence on plant
growth development and herbivore (NO
PESTICIDE STRESSES ADDED) Treatments
2 ? aphid levels x 5 fertility levels 10
trts.
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Quick Rinse of Aphid Exudate
Bottom Middle Apical
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Total Plant DM (g)
Fertility Level (ppm N)
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Total Bud DM (g)
0 19 38 75 375
Fertility Level (ppm N)
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Leaf DM (g)
Fertility Level (ppm N)
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Total Leaf Area (cm2)
0 19 38 75 375
Fertility Level (ppm N)
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Specific Leaf Area (cm2 g-1)
Fertility Level (ppm N)
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Ethylene Production Rate (pmol g-1 FW h-1)
Buds Young Phys. Mat Old
Leaf Leaf Leaf
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Pn (?mol CO2 m-2 s-1)
Young Phys. Mat Old Leaf
Leaf Leaf
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Young Leaves
N ()
Phys. Mat Leaves
0 19 38 75 375
Fertility Level (ppm N)
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Aphids No.
Fertility Level (ppm N)
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• Summary
• REDUCED PLANT QUALITY Aphids depressed plant
  vegetative and reproductive growth, and altered
  carbohydrate partitioning at high fertility.
• Aphid inoculated (AI) plants at high fertility
  had increased specific leaf area (SLA), i.e.
  thinner leaves and greater leaf area than
  aphid-free (NonAI) plants.
• Aphids caused greater ethylene production in
  reproductive buds and young leaves of high
  fertility plants, but had no effect on ethylene
  evolution in physiologically mature or older -
  basal leaves.

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• Summary (con.)
• AI plants had lower leaf N than NonAI
  treatments.
• Aphids reduced photosynthesis in young leaves of
  high fertility plants, whereas
  physiologically mature and older leaves were
  unaffected.
• Aphid abundance was greatest at high fertility.
• A higher proportion of aphids were observed in
  physiologically mature and older leaves at low
  fertility, whereas at high fertility young leaves
  had 33 more aphids than older, basal leaves.

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• Application to Stakeholders
• The morphology and physiological status of
  chrysanthemum determines its susceptibility to
  aphids.
• Aphids increase ethylene, decrease net
  photosynthesis, and decrease carbon allocation to
  leaves and reproductive structures, particularly
  at higher fertility.
• While growing plants under deficient fertility
  levels is not a satisfactory strategy for
  reducing insect pests, reducing fertility and
  pesticide levels and producing healthier, less
  stress susceptible plants is a realistic endeavor
  for best management practices (BMP) and IPM
  systems.

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Experiment Harvest
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Future

• One More Insect Herbivore - Leafminers.
• Increase Resolution of Reduced Inputs.
• IPM approach to include biological control.
• Demonstrations in Commercial Greenhouses.
• Incorporation of Plant Pathogen Management.
• Inclusion of Water and Water Nutrient Stresses.

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