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Use of trinexapac-ethyl to improve seed quality in mechanically planted sugarcane in Florida. C.R. Rainbolt, J.M. Shine, G. Powell, P. Grose, J. Larsen. Introduction. Ability to plant mechanically is critical to long term sustainability in Florida - PowerPoint PPT Presentation
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Use of trinexapac-ethyl to improve seed quality in mechanically planted sugarcane in Florida
C.R. Rainbolt, J.M. Shine, G. Powell, P. Grose, J. Larsen
Introduction
• Ability to plant mechanically is critical to long term sustainability in Florida
• Approximately 25-50% of hectares mechanically planted annually
Factors Limiting Mechanical Planting
• Poor stand quality compared to hand planting
• Requires more seed cane per acre in order to achieve a stand similar to hand planting– Mechanical damage to buds– Short billets are more susceptible to stalk rot– Seed cane metering device on planter is not precise
Trinexapac-ethyl• Trinexapac is a foliar absorbed plant
growth regulator • Interferes with gibberellic acid metabolic
pathway• Affects cell elongation, chilling
tolerance, and photoperiod response• Preliminary research indicated that
trinexapac can successfully reduce internode length in sugarcane
Objectives
1.Evaluate the efficacy of trinexapac for shortening internode length in sugarcane
2. Determine if planting seed cane treated with trinexapac results in more consistent emergence
Treatment with Trinexapac
• Commercial fields of CP 84-1198, CP 78-1628, CP 80-1743, CP 89-2143, CP 88-1762, and CL 77-797 were selected for treatment
• Trinexapac at 183 g ai/ha was applied at canopy closure (late spring)
• An additional 148 g ai/ha was applied ~6 weeks later
Seed Cane Data Collection
• 6 subsamples of trinexapac treated and nontreated seed cane of each cultivar were collected on October 17, 2005
• Each subsample consisted of 5 randomly collected stalks
Measurements
• Stalk internode lengths were determined using a tape
• Internode diameters were determined using a caliper
Average number of internodes per stalk
0
5
10
15
20
25
30
1198 1628 1743 2143 797 1762
cultivar
# o
f in
tern
od
es
Control
Trinexapac
NS at P= 0.05
Palisade Seed Piece 2005Average Internode Lengths
0
50
100
150
200
250
300
1198
Con
trol
1198
Trin
exap
ac
1628
Con
trol
1628
Trin
exap
ac
1743
Con
trol
1743
Trin
exap
ac
2143
Con
trol
2143
Trin
exap
ac
0797
Con
trol
0797
Trin
exap
ac
1762
Con
trol
1762
Trin
exap
ac
cultivar
inte
rno
de
len
gth
(c
m)
Average Internode LengthCultivar Trinexapac Control LSD
--------length ± SD (cm)------- (P=0.05)
CP84-1198 13.65 ± 1.81 14.18 ± 3.21 NS
CP78-1628 11.48 ± 3.04 12.69 ± 3.35 0.80
CP80-1743 12.86 ± 1.92 13.02 ± 2.88 NS
CP89-2143 9.01 ± 1.55 11.09 ± 2.68 0.52
CP88-1762 9.97 ± 2.03 10.79 ± 1.99 0.46
CL77-797 10.08 ± 2.01 9.61 ± 2.14 NS
797**Average Internode DiameterCultivar Trinexapac Control LSD
-------diameter ± SD (mm)------- (P=0.05)
CP84-1198 23.91 ± 2.05 23.58 ± 2.29 0.29
CP78-1628 23.21 ± 1.61 23.55 ± 2.80 NS
CP80-1743 24.93 ± 3.63 23.53 ± 3.45 0.43
CP89-2143 28.37 ± 2.95 24.52 ± 3.49 0.62
CP88-1762 26.07 ± 1.91 24.01 ± 2.00 0.35
CL77-797 26.65 ± 2.41 27.13 ± 2.18 0.31
Seed Cane Measurements Summary
• Treatment with trinexapac resulted in significantly shorter average internode lengths for CP 89-2143, CP 88-1762, and CP 78-1628
• Treatment with trinexapac resulted in larger internode diameters for all
• The average number of internodes per stalk and stalk weight were not affected by trinexapac
Field Trial
• Seed was mechanically harvested from each cultivar (site)
• Transported to a single site for planting in a randomized complete block design
• Cultivar was main treatment and split plots were treated and untreated
Field Trial Planting
• Plots were 8 rows wide 12.2 m by 12.2 m long
• Seed pieces (billets) were randomly chosen and planted November 17-19, 2005
• Single row placed end to end
• Thimet 20G was applied and seed cane was covered on November 19, 2005
Field Trial Data Collection
• Billets and nodes were counted in a 3.05 m section of 2 rows
• Shoot counts were conducted approximately every 2 weeks following emergence
• Shoots were counted in the middle 2 rows of each split-plot
• Trial will be taken to yield and repeated in 2006
0
2000
4000
6000
8000
10000
12000
14000
CP80-1743 CP88-1762 CP89-2143 CP78-1628 CP84-1198 CL77-797
Sho
ots
per
Hec
tare
Palisade Untreated
Shoot CountsDate 12/28/2005 - First Count
Planted 11/17-19/2005
NS
NS
A
AA
NS
B
BB
0
5000
10000
15000
20000
25000
30000
35000
40000
CP80-1743 CP88-1762 CP89-2143 CP78-1628 CP84-1198 CL77-797
Sho
ots
per
Hec
tare
Palisade Untreated
Shoot CountsDate 4/10/2006 - Ninth Count
Planted 11/17-19/2005
NS
B
A
A
A
B
B
NS
NS
Field Trial Summary
• The number of billets per plot was not different between treated and untreated plots
• The number of nodes per meter was only significantly higher in CP89-2143 and CP80-1743
• Treatment with trinexapac resulted in higher counts with CP89-2143, CP80-1743, CP78-1628
Conclusions
• Early results indicate that trinexapac can be used to improve seed cane quality and shoot counts in some cultivars
• Yield results will ultimately determine if there is value
• Modified application timings and doses may be necessary with some cultivars
• Registration for seed treatment is dependent ton ripener use registration
Questions