1. Harvesting William H. Bohl, Ph.D. Extension Professor Blackfoot, Idaho

2. Bulking Pattern of Russet Burbank in 2003 and 2004 at the Aberdeen R & E Center Cwt. per acre Month / Date % Dead Vines 5097100 152076cwt./acre:150 % Dead Vines 89710000 46 11 2 2131cwt./acre:162 Maximum Yield: 330 cwt./acre Maximum Yield: 453 cwt./acre

3. cwt./acre: Bulking Pattern of Ranger Russet in 2003 and 2004 at the Aberdeen R & E Center Cwt. per acre Month / Date % Dead Vines 1877100 Maximum Yield: 460 cwt./acre 52196108cwt./acre:132 % Dead Vines 0388 Maximum Yield: 502 cwt./acre 00 874519122110

4. Bulking Pattern of Alturas in 2003 and 2004 at the Aberdeen R & E Center Cwt. per acre Month / Date 84308135cwt./acre:100 0 6 % Dead Vines Maximum Yield: 412 cwt./acre 1286524143cwt./acre:87 % Dead Vines 011000 Maximum Yield: 500 cwt./acre

5. Days After Planting:105119133147 Total Yield Gain Over Two-Week Increments for the Last Eight Weeks of the Growing Seasons in 2003 - 2004 at the Aberdeen R & E Center Russet Burbank1042851 Russet Norkotah19200 CORN #310362271 Ranger Russet11769112 Alturas1411074615 Shepody11643112 Interval:8/1 - 8/148/15 - 8/288/29 - 9/119/12 - 9/25 2004: DAP – 106, 120, 134, and 148; Dates – 7/30 – 8/12, 8/13 – 8/26; 8/27 – 9/9, and 9/10 – 9/23 cwt./acre

6. ParmaAberdeen LocationMaximum Bulking RateLength of Linear BulkingRate of Linear Bulking (cwt/A/day)(days)(cwt/A/day) Parma10.11036.2 Aberdeen11.6407.2 Effect of Location on Bulking Rate of Russet Burbank ( 2003) Day after Planting cwt/acre Day after Planting Data From: Thornton, M. K. 2004. Unpublished

7. Probabilities of a 24.5°F Fall Freeze LocationEarliest10%20%30%40%50%60%70%80%90% Tetonia R & E9/049/089/129/159/199/239/269/3010/0410/12 Rexburg BYU-I9/199/209/229/2610/0710/0810/1110/1510/1610/21 Idaho Falls 2 ESE9/2710/0310/0610/0910/1410/1710/2010/2410/279/27 Blackfoot 2SSW9/189/2810/0310/0610/1310/1510/1710/1810/2610/31 Aberdeen R & E9/109/199/249/2810/0110/0610/0910/1410/1810/25 American Falls9/2310/0610/1210/1510/1810/2310/2710/3011/0211/07 Twin Falls9/1810/0710/1410/1610/2210/2710/3011/0211/0511/11 Parma R & E9/1810/0810/1510/1910/2310/2510/2810/3111/0411/10 Western Regional Climate Center, www.wrcc.dri.eduhttp://www.wrcc.dri.edu/summary/climsmid.html

8. Tuber Hydration Dehydrated (limp) Hydrated (crisp) % Damage Tuber Hydration Level Effect on Black Spot and Shatter Bruise of Russet Burbank at 42ºF Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164.

9. Tuber Temperature and Hydration Effects on Shatter and Blackspot Bruise Susceptibility of Russet Burbank Potatoes More Less % Bruised Potatoes Dehydrated (limp) Hydrated (crisp) Tuber Hydration Level 42  F 56°F 70°F Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164.

10. Height Blackspot Bruise @ 42°F Shatter Bruise @ 42°F Blackspot Bruise @ 56°F Shatter Bruise @ 56°F inches ---------------------------------------- % --------------------- ------------------- 653.50.812.30 1266.55.049.30.8 2441.051.370.310.5 Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164. Tuber Temperature and Force Effects on Blackspot and Shatter Bruise of Russet Burbank Potatoes Dropped a 3.5-oz plug one time on the bud and stem ends. Data is percentage of bruised areas developing detectable damage. Required twice as much force to develop shatter bruise compared with blackspot bruise.

12. Twelve rows of potatoes are being loaded at one time. Four rows in each windrow.

13. Flow of potatoes through a harvester.

15. Position on Harvester Where Tuber Bruising Occurs % Bruise Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164. BladePrimarySecondaryRear Cross ElevatorBoom 41% Cumulative damage by the time tubers reach the boom.

16. Tuber Loading on Conveyors Soil Loading: % Bruise Tuber Damage as Measured on Top of Side Elevator in Silt-Loam Soil Hyde, G. M. et al. 1990. Potato Harvester Chain Speed Adjustment. Washington State Univ. EB 1558.

17. Primary: Heavy soil: 120 – 150% Sand: 100 – 120% Rear Cross: 70% Set Conveyor Speeds as a Percent of Harvest Ground Speed Secondary: 65% Elevator: 70%

18. Iam A. Farmer September 3, 2003 422 Fry Lane, Spudtown 555-1234 1750414.82022.3 1.97 1.77 12 8 8 10 117 169 141 87 230 207 199 166 128 272 131 141 121 12 18 14 18 14 8 13 12 OK 50

19. Using Formulas to Adjust Harvester Conveyor Speeds: Harvest Ground Speed 1. (Distance in feet  Time in Seconds) x 60 = ft/min 1. (50 ft14.8 sec)60 sec/min202 ft/min  x = 2. ft/min  88 = miles per hour 2. 202 ft/min88 (ft/min/1 mph)2.3 mph  = 3. 2.3 mph88 (ft/min/1 mph)202 ft/min = x

20. Iam A. Farmer September 3, 2003 422 Fry Lane, Spudtown 555-1234 1750414.82022.3 1.97 1.77 12 8 8 10 117 169 141 87 230 207 199 166 128 272 131 141 121 12 18 14 18 14 8 13 12 OK 50

21. Potato Harvester Rear Cross Rear Cross Head Sprocket Determine conveyor pitch (distance between links) and number of teeth in head sprocket.

22. Measuring RPM’s of a head sprocket

23. Using Formulas to Adjust Harvester Conveyor Speeds: Current Conveyor Speed Conveyor Pitch (in.) x Number of Teeth in Head Sprocket x Head Sprocket RPM  12 in/ft = Current Conveyor Speed 1.77 in8 teeth169 RPM12 in/ft199 ft/min xx  = 45 mm  25.4 mm/in = 1.77 in

24. Iam A. Farmer September 3, 2003 422 Fry Lane, Spudtown 555-1234 1750414.82022.3 1.97 1.77 12 8 8 10 117 169 141 87 230 207 199 166 128 272 131 141 121 12 18 14 18 14 8 13 12 OK 50

25. Using Formulas to Adjust Harvester Conveyor Speeds: Desired Conveyor Speed Percent Ground Speed x Ground Speed in ft/min = Desired Conveyor Speed in ft/min.70 (70 %)202 ft/min141 ft/minx =

26. Change which Gear? Driver Gear Driven Gear

27. Potato Harvester Rear Cross Driver Gear 18 teeth on rear cross driver gear

28. Iam A. Farmer September 3, 2003 422 Fry Lane, Spudtown 555-1234 1750414.82022.3 1.97 1.77 12 8 8 10 117 169 141 87 230 207 199 166 128 272 131 141 121 2 12 18 14 18 14 8 13 12 OK 50

29. Using Formulas to Adjust Harvester Conveyor Speeds: Desired Sprocket Size (141 ft/min199 ft/min)18 teeth13 teeth  x = (Desired Conveyor Speed  Current Conveyor Speed) x Teeth in Current Sprocket = Desired Sprocket Size Use this formula when changing the driver sprocket.

30. Iam A. Farmer September 3, 2003 422 Fry Lane, Spudtown 555-1234 1750414.82022.3 1.97 1.77 12 8 8 10 117 169 141 87 230 207 199 166 128 272 131 141 121 12 18 14 18 14 8 13 12 OK 50 Newer harvesters generally have a hydraulically-driven boom conveyor, so there’s no need to change gears. * *

31. Other Places Potatoes May be Bruised during Harvesting and Handling

32. Keep stinger as close to truck as possible.

33. Another opportunity to bruise tubers as they unload from even-flow bin.

34. Here are a couple of “great” places to bruise tubers.

35. Pile tubers in stages to minimize roll back.

36. Educate, educate, educate harvest personnel to minimize bruise damage. Shatter bruise Black spot bruise

37. Summary of Bruise Management Considerations  Continually monitor tuber pulp temperature – ideal harvest tuber pulp temperature is 50 to 60°F  Adjust harvest time during the day to coincide with “ideal” tuber pulp temperature  Harvester conveyors must operate at speeds based on harvesting ground speed  Adjust windrower conveyors similar to harvester  Bruising can occur on any piece of equipment  Keep all tuber drop heights to a minimum  Run all conveyors at maximum capacity  Educate all harvest personnel about bruise management

38. Thank You March 6, 2014