Transcript Evaluation of K4 for Weed Control in Sandland Sugarcane

Evaluation of K4 for Weed
Control in Sandland
Sugarcane
C. Rainbolt, L. Baucum, and I. Ezenwa
Introduction
• K4 herbicide is a commercial mixture of
hexazinone and diuron
• Preemergence herbicide with some post
activity
• Registered for use in Florida sugarcane in
2005
• From the label “Do not use DuPont™ K-4™
on gravelly or rocky soils, thinly covered
subsoils, or coarse-textured soils (sands to
sandy loams) with less than 1% organic
matter”
Situation and Objective
• Previous research with K4 in FL has
focused on muck soils
• Based on chemical and soil properties,
ideal use rates will likely differ
• Objective: determine optimum use
patterns and rates for weed control and
crop safety on sandland sugarcane
Methods
• 5 trials were established on sandland
cane in 2005
• Trial 1- Duda, CP84-1198 ratoon
• Trial 2- Paige Farms, CP84-1198 ratoon
• Trial 3- ALICO, CP84-1198 plant
• Trials 4 & 5- USSC, CL88-4730 ratoon
• Plots were 4 rows wide x 40 ft long
Treatments
Treatment
Rate/A
Timing
K4 + NIS
1 lb + 0.25%
PRE and POST
K4 + NIS
2 lb + 0.25%
PRE and POST
K4 + NIS
3 lb + 0.25%
PRE and POST
K4 + Surfix
3 lb + 0.25%
PRE and POST
Aatrex + NIS
4 lb + 0.25%
PRE and POST
Prowl H2O + NIS
7 pt + 0.25%
PRE and POST
Valor + NIS
4 oz + 0.25%
PRE and POST
Valor + NIS
6 oz + 0.25%
PRE and POST
Aatrex + Prowl H2O + NIS
4 lb + 0.25%
PRE and POST
3 lb + 2 pt
POST
K4 + Unison
Treatment
Rate
Application
kg/ha
timing
hexazinone + diuron
0.15 + 0.53
PRE
hexazinone + diuron
0.3 + 1.05
PRE
hexazinone + diuron
0.45 + 1.6
PRE
atrazine
4.5
PRE
pendimethalin
3.7
PRE
flumioxazin
0.14
PRE
flumioxazin
0.21
PRE
4.5 + 3.7
PRE
hexazinone + diuron
0.15 + 0.53
EPOST
hexazinone + diuron
0.3 + 1.05
EPOST
hexazinone + diuron
0.45 + 1.6
EPOST
atrazine
4.5
EPOST
pendimethalin
3.7
EPOST
flumioxazin
0.14
EPOST
flumioxazin
0.21
EPOST
4.5 + 3.7
EPOST
atrazine + pendimethalin
atrazine + pendimethalin
untreated control
Tropical c
Duda Moore Haven
• Application information
– Preemergence: December 29, 2005
• Crop stage: emerging
• Weeds: emerging
– Postemergence: February 1, 2006
• Crop stage: 3-4 inch TVD
• Weeds: common ragweed, purple nutsedge,
spiny amaranth, dayflower, torpedograss, and
bermudagrass
Duda Moore Haven
PRE Results
• 14 days after PRE treatment (DAPRE),
crop injury was 3 to 5% with all Valor
and K4 treatments
• 34 DAPRE control of tropical crabgrass
was 84 to 94% with all PRE treatments
except Valor
• 34 DAPRE all treatments controlled
spiny amaranth 83 to 95%
Duda Moore Haven
Results- 26 days after post treatments
(DAPO)
• Control of tropical crabgrass was 85 to 95% with
K4 and Prowl H2O + Aatrex applied PRE
• Treatments with K4 at 2 or 3 lbs/A POST
controlled tropical crabgrass 95% or better
• Crop injury was 20% or higher with Valor
applied POST and 5 to 15% with K4 applied
POST
• Control of spiny amaranth was 90% or greater
with all treatments except K4 at 1 lb/A PRE and
Prowl H2O alone
Control
K4 at 3 lbs/A
26 DAPOST
Paige Farms
• Application information
– Preemergence: January 31, 2006
• Crop stage: emerging
• Weeds: emerging
– Postemergence: March 1, 2006
• Crop stage: 3-4 inch TVD
• Weeds: fall panicum, American black
nightshade, and common ragweed
Paige Farms
PRE Results – 27 DAPRE
• Control of fall panicum was 60, 78, and 90%
with K4 1, 2, and 3 lbs/A, respectively
• Control of fall panicum with Prowl H2O was
79%
• Crop injury with K4 ranged from 0 to 10%
and increased with higher rates
• American black nightshade and common
ragweed control were not significantly
different between treatments
Paige Farms Results- 41 DAPO
• Control of fall panicum with PRE
treatments was highest (85%) with K4 at 2
and 3 lbs/A
• Fall panicum control with POST
treatments was highest with treatments
containing K4 at 2 and 3 lbs/A
• Crop injury averaged 10% with treatments
containing 3 lbs of K4 and 5% with 2 lbs
of K4
Paige Farms 41 DAPO
Control
POST- K4 at 3 lb/A + Surfix
POST- Aatrex at 4 lbs/A
PRE- K4 at 3 lbs/A + NIS
ALICO
• Application information
– Preemergence: March 1, 2006
• Crop stage: emerging
• Weeds: emerging
– Postemergence: March 27, 2006
• Crop stage: 4-5 inch TVD
• Weeds: southern crabgrass and common
purslane
ALICO
Results – 26 DAPRE
• Control of southern crabgrass was
highest (88 to 89%) with K4 at 2 and 3
lbs/A and Prowl H2O+ Aatrex
• Common purslane control was 80% or
better with all treatments except Valor
• Crop injury averaged 5 to 9% with K4
at 2 and 3 lbs/A and Valor
ALICO Results- 15 DAPO
• Control of southern crabgrass was still
above 80% with PRE applications of K4 at
2 and 3 lbs/A and Prowl H2O + Aatrex
• POST treatments were too late for
successful southern crabgrass control (best
control was 65% with K4 at 3 lbs/A alone
and + Unison
• Crop injury was 11 to 20% with all K4
treatments
USSC
• Application information
– Preemergence: April 14, 2006
• Crop stage: emerging
• Weeds: emerging
– Postemergence: May 1, 2006
• Crop stage: 4-5 inch TVD
• Weeds: fall panicum, purple
nutsedge, spiny amaranth
• Two trials were conducted in adjacent fields
• PRE herbicide performance is negatively impacted by dry
soils
• One trial was irrigated with ~1 inch within 1 week of
herbicide application
USSC Results
• Data collection and analysis not
completed in time for presentation
• A report including a full analysis of
results from all locations will follow in
late summer
Conclusions
• Crop injury tends to be more severe in
plant cane and larger cane (>4” to TVD)
• Crop injury may be more severe in
warmer conditions when cane is growing
faster
• Results indicate that 2-3 lbs applied PRE
or very early POST provides weed
control similar or better than standard
treatments
Acknowledgements
• Many thanks to:
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Paige Farms
Duda
USSC
ALICO
DuPont