1. Impact of Subfreezing Temperatures on the 2006 Louisiana Sugarcane Crop Benjamin L. Legendre Interim Director/Professor Audubon Sugar Institute St. Gabriel, Louisiana USA Factory Operations Seminar - 2007

2. Contours prepared by Jay Grymes, LSU AgCenter Base Map provided by LSU Cartographic Section Dept. of Geography & Anthropology Data Sources: National Weather Service LSU Southern Regional Climate Center Louisiana Office of State Climatology LAIS, LSU AgCenter Probabilities Derived from ACIS / CLIMOD tools, LSU Southern Regional Climate Center 50% < 50% ‘Deep-Freeze’ Probability Generalized Likelihood of a Temperature ≤ 24ºF by/before December 10th 50% 40% 30% 40% 30% 20% 10% Less than a 1-in-10 chance of a 24º temperature by/before December 10 a 24º temperature by/before December 10 Better than a 50-50 chance Better than a 50-50 chance of a 24º temperature by/before December 10 50% 40% 30% 20% 10%

3. 32º 28º 30º 26º 24º 22º 24º 26º 28º 32º 20º 18º Early December 2006 “Arctic Outbreak” 9 December 2006 Generalized Distribution of Minimum Temperatures (ºF) Contours prepared by Jay Grymes, LSU AgCenter Base Map provided by LSU Cartographic Section Dept. of Geography & Anthropology Data Sources: National Weather Service LSU Southern Regional Climate Center Louisiana Office of State Climatology LAIS, LSU AgCenter 24º 26º 18º 20º 22º 28º 20º 30º

4. 2006 December Freeze Events Temperature Extremes ( °F) LSU Dean Lee Research20 Bunkie 22 Baton Rouge 22 Donaldsonville26 Thibodaux27 Lake Charles24 St. Martinville24 New Iberia24 Jeanerette25 Franklin26 Houma 29 Source: Louisiana Office of State Climatology, Dept. of Geography & Anthropology

5. Background: Freeze Damage to Sugarcane  The nature and extent of damage to cane by a freeze depends upon the intensity and duration of the freeze Temperatures above 28°F do little more than affect terminal buds and tender leaves. You can generally still plant the stalk. Sucrose content continues to rise Temperatures between 26-27°F kill growing point and top third of stalk. Most lateral buds are killed. Sucrose content and purity increase for short time due to dehydration. Minimal deterioration for 4-6 weeks assuming one can remove top 6-12” of stalk

6. Background: Freeze Damage to Sugarcane  The nature and extent of damage to cane by a freeze depends upon the intensity and duration of the freeze Temperatures between 23-25°F kill most tissue. Lateral buds begin to weep and allow entrance of bacteria into tissue producing dextran. Expect some deterioration in 2-4 weeks depending upon variety and post-freeze weather conditions. Recommend removal of 12-18” at top of stalk Temperatures below 22°F kill all tissue and generally cause the rind to split (freeze cracks) allowing entrance of bacteria into tissue producing dextran. Expect serious deterioration in 1-2 weeks. Should still remove top 12-18”

7. Background: Freeze Damage to Sugarcane  There are significant differences amongst varieties in their tolerance to sub-freezing temperatures between 24-27°F. Consider a harvest schedule based on varieties, location of field, lodged condition of the cane and stand  Two mechanisms have been noted when testing varieties for post-freeze tolerance Susceptibility of the tissue to sub-freezing temperatures Susceptibility of the tissue to bacterial invasion and subsequent production of mannitol and/or dextran

8. Background: Freeze Damage to Sugarcane  Deterioration is enhanced by warm temperatures, high humidity and fog following sub-freezing conditions  Colder temperatures and consequently greater damage is generally found in low lying areas when compared to ridges and/or higher ground  Cane that is lodged is affected differently than cane that is erect. Generally speaking, lodged cane is more affected  Thin stands of cane are generally more affected by sub- freezing temperatures than good stands

9. Background: Freeze Damage to Sugarcane  Frozen cane harvested by combine deteriorates faster than whole-stalk cane especially if burned before harvest. Proper management must be used on the farm and at the factory following freeze events to ensure optimal quality

10. Reaction of Louisiana Sugarcane Varieties to Sub-freezing Temperatures VarietyReaction LCP 85-384Mod. Resistant HoCP 85-845 Intermediate HoCP 91-555 Susceptible Ho 95-988 Intermediate HoCP 96-540 Mod. Resistant L 97-128 Intermediate

11. Indicators of Deterioration Following Sub- freezing Temperatures  Indicators of deterioration to the producer  Decrease in pH of juice  Increase in titratable acidity  Decrease in sucrose content  Decrease in purity  Decrease in recoverable sugar per ton of cane  Increase in polysaccharides, notably dextran

12. Reaction of LCP 85-384 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9 (13 hr). Low temperature: 25°F

13. Reaction of LCP 85-384 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9 (13 hr). Low temperature: 25°F Variety Sample dateWt.BrixPurityTRSFiberTRS Juice pHAcidity LCP85-38412/112.5718.686.1022819.922025.391.61 12/202.7519.089.9024918.992265.531.14 01/032.6918.287.1022820.361995.401.31 01/192.2618.388.5023419.992075.491.24 Mean2.5718.587.9023519.822085.451.33

14. Reaction of LCP 85-384 to Sub-freezing Temperatures - Field Observations Frozen top Unfrozen stalk

15. Reaction of HoCP 96-540 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9, 2006 (13 hr). Low temperature: 25°F

16. Reaction of HoCP 96-540 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9, 2006 (13 hr). Low temperature: 25°F VarietyDateWt.BrixPurityTRSFiberTRS Juice pHAcidity HoCP 96-54012/113.1218.385.2022219.122005.441.66 12/203.0318.787.9023718.532175.551.43 01/032.7418.488.0023018.282125.471.56 01/192.8717.888.5022818.322105.551.41 Mean2.9418.387.4022918.562105.501.52

17. Reaction of L 99-226 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9, 2006 (13 hr). Low temperature: 25°F

18. Reaction of L 99-226 to Sub-freezing Temperatures Ardoyne Farm (USDA-ARS, SRRC, SRL) Chacahoula Freeze Dates & Duration: December 5 (9 hr), 6 (7 hr), 8 (5 hr) & 9, 2006 (13 hr). Low temperature: 25°F VarietyDateWt.BrixPurityTRSFiberTRS Juice pHAcidity L 99-22612/113.3119.088.4024318.532235.511.55 12/203.1318.687.0023218.472125.661.42 01/033.6618.788.1023719.572135.441.46 01/193.3517.483.4020418.811865.391.65 Mean3.3618.486.7322918.562095.501.52

19. Simple Field Test for Determining pH of Juice to Detect Deteriorated Cane Pliers pH indicator strips

20. Indicators of Deterioration Following Sub-freezing Temperatures  Indicators of deterioration to the processor  Increase in sucrose losses  Increase in viscosity of syrups and molasses  Decrease in filterability  Elongated and deformed sugar crystals  Rate of crystallization markedly reduced because of increase in viscosity  Dextran in sugar  Increase in molasses purity and volume

21. Increases in Polysaccharide

22. Increases in Dextran

23. Changes in Processing Parameters Following December Freeze Events ParametersPre-Freeze 12/02/06 (Week 9) Post-Freeze 12/30/06 (Week 13) Change(%) Pol % Cane 12.14 10.17 10.17(-17%) Abs. J. Purity 83.51 80.34 80.34 (- 4%) Syrup Purity 85.87 83.14 83.14 (- 3%) Molasses Pur. 32.55 34.65 34.65 (+ 6%) Sugar Yield 212.53168.48(-21%) Taken from Weekly Comparative Manufacturing Report Prepared by Dr. Harold Birkett

24. Crystal Elongation Caused by Dextran Following Sub-freezing Temperatures Sometimes called “Needle Grain”

25. Conditions Following Freeze Events Were Favorable to Increased Leafy Trash, Tops and Mud Wet & lodged fields Equal cane with trash

26. Impact of Trash on Cane and Juice Quality  Reduction in sucrose of 0.10 units  Reduction in purity of 0.28 units  Reduction in extraction of 0.37 units  Increase in fiber of 0.18 units (w/new formula this increase is 0.23 units) formula this increase is 0.23 units)  Reduction in sugar yield of 3.0 lbs (1.36 kg)  For each 1% in cane trash, one can expect the following impact upon quality parameters

27. Question Following Freeze Events Were the losses experienced following the early December freeze events in 2006 the result of cane deterioration or were the losses the result of the increase in leafy trash, deteriorated tops and mud caused by the excessive rainfall (Average of 9.92” across Southwest, South-Central and Southeast Louisiana or +4.88” above normal) following the freeze events or was it the combination of the two weather events? I believe that it was the combination of the two weather events although the freeze events took their toll especially in the northern areas of the state.

28. AcknowledgementsAcknowledgementsCo-investigators Harold Birkett Harold Birkett Gillian Eggleston Gillian Eggleston Jeanie Stein Jeanie Stein Chris Finger Chris Finger

29. Questions and/or Comments? Mexico North Dakota Louisiana