Harvesting

William H. Bohl, Ph.D.

Extension Professor

Blackfoot, Idaho

6/5 6/19 7/3 7/17 7/31 8/14 8/28 9/11 9/25

0

40

80

120

160

200

240

280

320

360

400

440

480

Yield Dead Vines

6/3 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/230

40

80

120

160

200

240

280

320

360

400

440

480

Yield Dead Vines

Bulking Pattern of Russet Burbank in 2003 and 2004 at the Aberdeen R & E Center

Cwt.

per

acre

Month / Date

% Dead Vines50 97 100

15 2 076cwt./acre: 150

% Dead Vines8 97 10000

46 1111 22131cwt./acre: 162

Maximum Yield: 330 cwt./acre

Maximum Yield: 453 cwt./acre

6/3 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/230

40

80

120

160

200

240

280

320

360

400

440

480

520

Yield Dead Vines

cwt./acre:

6/5 6/19 7/3 7/17 7/31 8/14 8/28 9/11 9/250

40

80

120

160

200

240

280

320

360

400

440

480

520

Yield Dead Vines

Bulking Pattern of Ranger Russet in 2003 and 2004 at the Aberdeen R & E Center

Cwt.

per

acre

Month / Date

% Dead Vines18 77 100

Maximum Yield: 460 cwt./acre

52 19 6108cwt./acre: 132

% Dead Vines0 3 88

Maximum Yield: 502 cwt./acre

00

87 45 19122110

6/5 6/19 7/3 7/17 7/31 8/14 8/28 9/11 9/250

40

80

120

160

200

240

280

320

360

400

440

480

Yield Dead Vines

6/3 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/230

40

80

120

160

200

240

280

320

360

400

440

480

Yield Dead Vines

Bulking Pattern of Alturas in 2003 and 2004 at the Aberdeen R & E Center

Cwt.

per

acre

Month / Date

84 30 8135cwt./acre: 100

0 6 100% Dead Vines

Maximum Yield: 412 cwt./acre

128 65 24143cwt./acre: 87

% Dead Vines0 1 1000

Maximum Yield: 500 cwt./acre

Days After Planting: 105 119 133 147

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 Burbank 104 28 5 1

Russet Norkotah 19 2 0 0

CORN #3 103 62 27 1

Ranger Russet 117 69 11 2

Alturas 141 107 46 15

Shepody 116 43 11 2

Interval: 8/1 - 8/14 8/15 - 8/28 8/29 - 9/11 9/12 - 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

Parma Aberdeen

Location Maximum Bulking Rate Length of Linear Bulking Rate of Linear Bulking

(cwt/A/day) (days) (cwt/A/day)

Parma 10.1 103 6.2

Aberdeen 11.6 40 7.2

Effect of Location on Bulking Rate of Russet Burbank (2003)

63 77 91 105 119 133 1470

100

200

300

400

500

600

700

60 72 85 99 114 130 141 155 169 1840

100

200

300

400

500

600

700

Day after Planting

cwt/

acre

Day after Planting

Data From: Thornton, M. K. 2004. Unpublished

Probabilities of a 24.5°F Fall Freeze

Location Earliest 10% 20% 30% 40% 50% 60% 70% 80% 90%

Tetonia R & E 9/04 9/08 9/12 9/15 9/19 9/23 9/26 9/30 10/04 10/12

Rexburg BYU-I 9/19 9/20 9/22 9/26 10/07 10/08 10/11 10/15 10/16 10/21

Idaho Falls 2 ESE 9/27 10/03 10/06 10/09 10/14 10/17 10/20 10/24 10/27 9/27

Blackfoot 2SSW 9/18 9/28 10/03 10/06 10/13 10/15 10/17 10/18 10/26 10/31

Aberdeen R & E 9/10 9/19 9/24 9/28 10/01 10/06 10/09 10/14 10/18 10/25

American Falls 9/23 10/06 10/12 10/15 10/18 10/23 10/27 10/30 11/02 11/07

Twin Falls 9/18 10/07 10/14 10/16 10/22 10/27 10/30 11/02 11/05 11/11

Parma R & E 9/18 10/08 10/15 10/19 10/23 10/25 10/28 10/31 11/04 11/10

Western Regional Climate Center, www.wrcc.dri.edu http://www.wrcc.dri.edu/summary/climsmid.html

Series10

10

20

30

40

50

60

70

80

90

100

Black SpotShatterTotal

Tuber HydrationDehydrated (limp) Hydrated (crisp)

% D

amag

eTuber 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.

Tuber Temperature and Hydration Effects on Shatter and Blackspot Bruise Susceptibility of

Russet Burbank Potatoes

More

Less

% B

ruis

ed

Po

tato

es

Dehydrated (limp)

Hydrated (crisp)

Tuber Hydration Level

42F

56°F

70°F

Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164.

HeightBlackspot Bruise @

42°F

Shatter Bruise @

42°F

Blackspot Bruise @

56°F

Shatter Bruise @

56°F

inches ---------------------------------------- %

----------------------------------------

6 53.5 0.8 12.3 0

12 66.5 5.0 49.3 0.8

24 41.0 51.3 70.3 10.5

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 PotatoesDropped 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.

Twelve rows of potatoes are being loaded at one time.

Four rows in each windrow.

Flow of potatoes through a harvester.

Flow of potatoes through a harvester.

Position on Harvester Where Tuber Bruising Occurs

% B

ruis

e

Smittle, D.A., et al. 1974. Harvesting Potatoes with Minimum Damage. Am. Potato J. 51: 153-164.

Blade Primary Secondary Rear Cross

Elevator BoomSeries10

5

10

15

20

25

30

35

40

45

41% Cumulative damage by the time tubers reach the boom.

Low Medium High0

5

10

15

20

25

30

35

Low Medium High

Tuber Loading on Conveyors

Soil Loading:

% B

ruis

eTuber 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.

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%

Iam A. Farmer September 3, 2003

422 Fry Lane, Spudtown 555-1234

1750 4 14.8 202 2.3

1.97

1.77

1.77

1.77

1.77

12

12

8

8

10

117

117

169

141

87

230

207

199

166

128

272

131

141

141

121

12

12

18

14

18

14

8

13

12

OK

50

Using Formulas to Adjust Harvester

Conveyor Speeds: Harvest Ground

Speed1. (Distance in feet Time in Seconds) x 60 =

ft/min1. (50 ft

14.8 sec) 60 sec/min 202 ft/min x =

2. ft/min 88 = miles per

hour2. 202 ft/min

88 (ft/min/1 mph) 2.3 mph =

3. 2.3 mph 88 (ft/min/1 mph)

202 ft/min = x

Iam A. Farmer September 3, 2003

422 Fry Lane, Spudtown 555-1234

1750 4 14.8 202 2.3

1.97

1.77

1.77

1.77

1.77

12

12

8

8

10

117

117

169

141

87

230

207

199

166

128

272

131

141

141

121

12

12

18

14

18

14

8

13

12

OK

50

Potato Harvester Rear Cross

Rear Cross Head Sprocket

Determine conveyor pitch (distance between links) and number of teeth in head sprocket.

Measuring RPM’s of a head sprocket

Using Formulas to Adjust Harvester

Conveyor Speeds: Current Conveyor

SpeedConveyor Pitch (in.) x Number of Teeth in

Head Sprocket x Head Sprocket RPM 12

in/ft = Current Conveyor Speed

1.77 in

8 teeth 169 RPM

12 in/ft 199 ft/minx x =

45 mm 25.4 mm/in = 1.77 in

Iam A. Farmer September 3, 2003

422 Fry Lane, Spudtown 555-1234

1750 4 14.8 202 2.3

1.97

1.77

1.77

1.77

1.77

12

12

8

8

10

117

117

169

141

87

230

207

199

166

128

272

131

141

141

121

12

12

18

14

18

14

8

13

12

OK

50

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/min 141 ft/minx =

Change which

Gear?Driver Gear

Driven Gear

Potato Harvester Rear Cross Driver Gear

18 teeth on rear cross driver gear

Iam A. Farmer September 3, 2003

422 Fry Lane, Spudtown 555-1234

1750 4 14.8 202 2.3

1.97

1.77

1.77

1.77

1.77

12

12

8

8

10

117

117

169

141

87

230

207

199

166

128

272

131

141

141

121

2

12

18

14

18

14

8

13

12

OK

50

Using Formulas to Adjust Harvester

Conveyor Speeds: Desired Sprocket

Size

(141 ft/min

199 ft/min)

18 teeth 13 teeth x =

(Desired Conveyor Speed Current Conveyor

Speed) x Teeth in Current Sprocket = Desired

Sprocket SizeUse this formula when changing the driver sprocket.

Iam A. Farmer September 3, 2003

422 Fry Lane, Spudtown 555-1234

1750 4 14.8 202 2.3

1.97

1.77

1.77

1.77

1.77

12

12

8

8

10

117

117

169

141

87

230

207

199

166

128

272

131

141

141

121

12

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.

*

*

Other Places Potatoes May be Bruised during Harvesting and Handling

Keep stinger as close to truck as possible. Keep stinger as close to truck as possible.

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

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

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

Pile tubers in stages to minimize roll back.

Educate, educate, educate harvest personnel to minimize bruise damage.

Shatter bruise

Black spot bruise

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

Thank You

March 6, 2014