Download Present - University of Florida

Biology and Control of Floating
Heart (Nymphoides cristata)
Leif Willey – University of Florida Center
for Aquatic and Invasive Plants
Infestation pic
Nymphoides - Dicotyledons
• About 50 species world wide
– All aquatic, found on every continent except Antarctica
– Common weeds in rice fields
• 5 species found in US (2 natives)
– all 5 found in FL
• Nymphaeid growth
• Multiple methods of vegetative spread
Nymphaeid Growth Form
Floating leaves
Elongated
stem
Sediment
surface
roots
N. cristata
N. cristata
Distribution of Exotic Nymphoides in the US
Jacono and Langeland
Distribution of Native Nymphoides
Nymphoides aquatica
Nymphoides cordata
Identification
-N. peltata(introduced)
N. Cristata (introduced)
N. Cordata (native)
N. Aquatica (native)
N. indica (introduced)
Feathery projections
covering petal
N. cristata(introduced)
Erect Longitudinal Crest
N. cordata and N. aquatica
(Natives)
Buying Invasives Online
• Out of state
• In state
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http://www.pondplants.com
http://toptropicals.com/
https://www.pondmegastore.com
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http://www.pondplants2you.com
http://www.pondworld.com
http://www.blueridgefish.com
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Aquatic nursery Industry ~ $1billion
http://www.floridaaquatic.com
http://www.aquariumplants.com
http://asr4ponds.com/
http://www.coolponds.com
N. Cristata (crested
floating heart)
Native to Asia
-First report 1996
-few scientific studies
ID characteristics
- flower
- floating leaves
-habitat
Invasiveness
- Spread
-Problems
Why Study Floating Heart ?
• Continuing to Spread
– Water gardens and site transfer
• Very limited information on N. cristata
• Difficult to manage
– Low success rate with various herbicide approaches
– no accepted standard for control
• Grass carp are not a viable option
– Rapid spread in Lake Marion/Moultrie (Other SE
Reservoirs where carp are stocked ?)
N cristata is a Category 1 Invasive
species in FL(2009)
Category1: invasive exotic that is
displacing native species, changing
community structures, or ecological
functions. Present in natural areas
Invasive potential
N. Cristata in Lake Marion, SC
20 acres to 2000 acres in 2 yrs
• Spread
• Competitive ability
• Herbicide response
-current techniques
Canal
in
SW
Florida
Canal pic
N. Cristata Growth studies
• Soil type and soil fertility
• Light Intensity
Pic of daughter plant
“starting with low biomass”
Sediment & Fertility
Mean Number of Emergent Leaves with 95% CI
-Orange Lake (77% O.M)
-Potting soil mix
• Highly fertile sand sediment
yielded greatest growth
• Non amended lake
sediments = poor growth
• Growth more dependent
on nutrient availability
than sediment type
60
0g/kg
1g/kg
4g/kg
40
20
0
Potting Soil
Muck
Sand
Soil Type
Mean Dry Weigh (g) with 95% CI
40
30
Dry weight (g)
• 3 soil types
-L ake Toho (97% sand),
# of Emergent Leaves
80
0g/kg
1g/kg
4g/kg
20
10
0
Potting Soil
Muck
Soil type
Sand
Light Intensity
Mean Number of Emergent Leaves with 95%CI
# of Emergent Leaves
• Daughter plants established at 5 light
intensities
– (1, 5, 25, 50 & 100% incident light)
16
2week
4week
14
12
10
8
6
4
2
0
1%
5%
25%
50%
100%
Percent Incident Light at Water Surface
• Measured parameters peaked at 25%
light
5
Dry Weight (g)
• At 1% light (~20 µmoles) - daughter
plants produced small viable leaves
that reached the water surface
Mean Dry Weight (g) with 95% CI
2week
4week
4
3
2
1
0
1%
5%
25%
50%
100%
Percent Incident Light at Water Surface
Management Research Objectives
• Determine response of N. cristata to herbicides
• Does method of application influence efficacy?
– Emergent vs. submersed
• Does herbicide formulation influence efficacy ?
– Granular vs. liquid
• Determine factors that influence herbicide
translocation
– E.g. water depth, leaf surface area
Translocation ?
Herbicide Screening
• All registered aquatic herbicides evaluated
- Comparative Trials – Focusing on short exposure times
- Exception – ALS herbicides and Fluridone = static exposures
• Method of application
– Emergent
– Submersed
* liquid vs. granular
Growth regulators
Mean Dry Weight at 24hr. Exposure 4WAT
mean dry weight
dry weight (g)
60
• 2,4-D and Triclopyr - dicots
• 24 and 96 hour exposures
20
– Liquid and granular
0
PT
Con
2.5(S) 1.25(S) 2.5(G) 1.25(G) 4qt(F)
2qt(F)
Triclopyr treatments
triclopyr 96 hour exposure mean dry weight and 05% CI
MEAN
60
dry weight(g)
• Emergent 1 to 4 qts/acre
• No reduction of biomass
at 4 WAT
• Limited visual injury
40
40
20
0
PT
CON
2.5S
treatments
2.5G
Contact Herbicides 24hour Exposure mean weights
60
Contact herbicides
Dry Weight (g)
50
40
30
20
10
0
PT
CON
A3S A1.5S A3G A1.5G D185
D93
F400 F200
treatments
Contact Herbicides 96 hour Exposure and Foliar mean weights
60
Col 6
50
Dry weight (g)
• 24 & 96 hour exposures
• Foliar and submersed
strategies tested
• Formulation had limited
impact
• Greater reductions in biomass
at 96 hour exposure
Mean
40
30
20
10
0
PT
CON
A3S
A3G
Treatment
D185
A2Q
D2Q
Contact herbicides
cont.
Contact herbicides 24H. mean dry weights w/ 95%CI
20
mean
18
16
14
Dry weight (g)
• Diquat at 370 ppb
regrew to pre treatment
dry weights with 24 Hr
exposure
• Hydrothol was most
effective at preventing
regrowth
12
10
8
6
4
2
0
PT
CON
D370
treatment
H.5S
H.25S
Systemic herbicides
Mean Dry Weights with 95% CI for ALS Herbicides
100
mean dry weight
80
Dry weight (g)
• Static exposures
• Foliar and submersed
treatments
• Imazamox and Imazapyr
applied foliar yielded fast
burn down with no regrowth
at 4 WAT.
• Glyphosate alone not
effective
60
40
20
0
PT
CON
G(2qt) IM(4qt) IP(2qt) P(5.4oz) P(20)
ALS Herbicide Treatments
IM(250)
Results and Ongoing Research
• Herbicides –
– good at removing surface leaves
– Poor at controlling the plant
• Compare foliar and submersed strategies for
the most active herbicides
– Strategies to control daughter plants
• Competition studies with hydrilla
Hydrilla and Nymphoides –
-Growth at low light intensities
-Growth from propagules (tubers or
daughter plants
Rapid growth to water surface
Formation of large contiguous canopies
Grass Carp
- Love Hydrilla
- Hate Nymphoides
Questions?