Use of trinexapacethyl to improve seed quality in mechanically planted sugarcane in Florida

1
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

2
Introduction

• Ability to plant mechanically is critical to long
  term sustainability in Florida
• Approximately 25-50 of hectares mechanically
  planted annually

3
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

4
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

5
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

6
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

7
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

8
Measurements

• Stalk internode lengths were determined using a
  tape

• Internode diameters were determined using a
  caliper

9
(No Transcript)
10
(No Transcript)
11
Average Internode Length
12
797Average Internode Diameter
13
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

14
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

15
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

16
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

17
A
NS
A
NS
B
NS
B
A
B
18
NS
A
NS
A
B
NS
A
B
B
19
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

20
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

21
Questions