The document discusses pruning and spacing techniques for tomatoes grown in high tunnels, finding that pruning to a single or double stem increases yield and fruit size for determinate varieties, while removing suckers increases and prolongs yield for indeterminate varieties. Closer plant spacing of 12-18 inches produced higher early and total yields compared to 24 inch spacing. Proper pruning and spacing techniques can optimize tomato production in high tunnel systems.

1. Pruning and Spacing
Tomatoes in High
Tunnels
Terrance T, Nennich
Extension Professor
Fruit and Vegetable Production
University of Minnesota Extension

2. NCROC
 These studies were conducted at the North
Central Research and Outreach Center , Grand
Rapids Minnesota

4. Pruning
 Increases fruit size.
 Promotes earlier harvest
 Reduces disease incidence.
 Reduces grey wall.
 Better air flow

5. Pruning is most
practical for…
•Small tomato
plantings.
•High Tunnel tomato
varieties.
•Late-season
determinate varieties.

6. Pruning
Timeliness is of the
most Importance

8. Determinate Types
Bush tomatoes
Ends with terminal buds
Easier to prune
Growth is smaller
Most new releases are determinate
Act different in high tunnels

9. Pruning Determinant
Types
Wait until plant has first flowers and tomato is the
size of a nickel
Going down skip one branch
Prune out everything below
Can be pruned to one or two leaders
This will increase size and make a earlier harvest.

10. Non-pruned
Pruned

14. Determinate Tomato Pruning Study
Lbs/Plant Ripe Fruit Harvest
Pruning 1st % # Fruit/ Lbs / Lbs/
Early* Ripe
Treatment Ripe Good Plant Fruit Sq. Ft.
2003-Cultivar Debut
Single Stem 7/24 2.5 8.8 63% 17.0 0.534 1.40
Double Stem 7/21 1.9 12.3 58% 25.2 0.505 1.95
2004-Cultivar Sunshine
Single Stem 7/26 1.6 10.5 76% 19.6 0.534 1.67
Double Stem 7/23 1.2 12.1 73% 23.2 0.523 1.92
No Prune 8/9 0.0 22.1 81% 47.8 0.462 3.51
* Early harvest through 8/2

17. Do not over prune. Fruit needs leaf cover to prevent sunburn.
Source: L. Kamar

18. Indeterminate Types
 Continual Growth
 7-15 foot of height.
 Continual tomato production
 Even production
 Smaller production in given time.

20. Pruning Indeterminate
Types
Wait until plant has first flowers and tomato is the
size of a nickel
Going down skip one sucker branch
Prune out everything below
Can be pruned to one or two leaders
All suckers must be removed during the season.

22. Sucker or axillary
shoot
Must be less than 4
inches long.

23. PRUNING TOMATOES

24. Indeterminate Tomato Pruning Study- Cobra
2004 Lbs/Plant Ripe Fruit Harvest
Pruning 1st % # Fruit/ Lbs / Lbs/
Early* Ripe
Treatments Ripe Good Plant Fruit Sq. Ft.
Single Stem 8/6 0.1 15.5 74% 35.6 0.436 2.46
Double Stem 8/12 0.0 17.0 73% 46.4 0.367 1.70
No Prune 8/19 0.0 13.6 61% 47.8 0.286 2.16
* Early harvest through 8/2/04

25. 2006 Indeterminate Tomato Production - Cobra
Lbs/Plant Ripe Fruit Harvest
1st % # Fruit/ Lbs / Lbs/
Early* Ripe Total
Treatment Ripe Good Plant Fruit Sq. Ft.
Spacing
18" 7/20 5.8 15.7 24.9 b 64% 40.7 b 0.392 2.50
24" 7/20 7.2 19.5 29.7 a 66% 48.1 a 0.407 2.32
Stems
Single 7/19 6.7 16.2 24.8 b 65% 37.7 b 0.428 a 2.23
Double 7/21 6.4 19.0 29.8 a 64% 51.1 a 0.372 b 2.58
* Early harvest through 8/2/06

29. Sanitation
Prune with clean tools
Disinfect while using
If there any plants that are stunted
or diseased do them last or pull
them out.

30. Spacing Studies

31. Spacing Studies
 Will plant spacing make a difference with
 Earliness??
 Tomato Size ??
 Total yield??

32. Determinate Tomato Spacing Study
Lbs/Plant Ripe Fruit Harvest
1st % # Fruit/ Lbs / Lbs/
Early* Ripe
Spacing Ripe Good Plant Fruit Sq. Ft.
2003-Cultivar Debut
12” 7/24 3.1 9.1 68% 16.7 0.558 2.17
18” 7/21 2.9 8.3 68% 18.0 0.476 1.32
24” 7/21 4.0 8.3 59% 13.7 0.583 0.99
2004-Cultivar Sunshine
12” 7/23 1.2 7.9 72% 17.0 0.467 1.88
18” 7/28 1.0 8.1 79% 17.8 0.458 1.28
24” 7/26 1.2 9.8 69% 17.8 0.550 1.17
* Early harvest through 8/2

33. 2006 Determinate Tomato Production
– Sunstart
Lbs/Plant Ripe Fruit Harvest
% # Fruit/ Lbs/ Lbs/
Early* Ripe Total
Treatment Good Plant Fruit Sq. Ft.
Stems x Spacing
Single 12" 5.15 b 7.47 b 11.00 c 69% 18.4 b 0.409 1.78 bc
Single 18" 5.10 b 8.70 b 12.52 c 70% 20.0 b 0.440 1.38 cd
Single 24" 5.20 b 7.95 b 11.99 c 66% 17.6 b 0.459 0.95 d
Double 12" 6.52 ab 9.50 ab 14.51 bc 65% 23.3 ab 0.410 2.26 a
Double 18" 7.60 a 12.13 a 17.62 ab 70% 29.0 a 0.421 1.93 ab
Double 24" 7.51 a 11.95 a 18.66 a 65% 28.2 a 0.425 1.42 cd
* Early harvest through 8/2/06

34. 2006 Determinate Tomato Production
- Sunstart
Lbs/Plant Ripe Fruit Harvest
1st % # Fruit/ Lbs/ Lbs/
Early* Ripe Total
Treatment Ripe Good Plant Fruit Sq. Ft.
Spacing
12" 7/8 5.8 8.5 b 12.8 67% 20.9 0.409 2.02 a
18" 7/6 6.4 10.4 a 15.1 70% 24.5 0.431 1.66 b
24" 7/7 6.4 10.0 ab 15.3 65% 22.9 0.442 1.18 c
Stems
Single 7/7 5.2 b 8.0 b 11.8 b 68% 18.7 b 0.436 1.37 b
Double 7/7 7.2 a 11.2 a 16.9 a 67% 26.8 a 0.419 1.87 a
* Early harvest through 8/2/06

35. Sunstart Yield By Fruit Category
(lbs/sq. ft.)
Treatment Early* Good Spoiled Immature Total
Single 12" 1.23 b 1.78 bc 0.60 ab 0.24 cd 2.62 bc
Single 18" 0.81 cd 1.38 cd 0.27 c 0.34 bc 1.99 cd
Single 24" 0.62 d 0.95 cd 0.33 c 0.15 cd 1.43 d
Double 12" 1.55 a 2.26 a 0.63 a 0.57 a 3.46 a
Double 18" 1.21 b 1.93 ab 0.46 abc 0.41 ab 2.80 ab
Double 24" 0.89 c 1.42 cd 0.40 bc 0.40 abc 2.22 bc
* Early harvest through 8/2/06

36. 2006 Indeterminate Tomato Production – Cobra
Lbs/Plant Ripe Fruit Harvest
1st % # Fruit/ Lbs / Lbs/
Early* Ripe Total
Treatment Ripe Good Plant Fruit Sq. Ft.
Stems x Spacing
Single 18" 7/19 6.4 15.4 24.1 b 64% 61.3 c 0.434 a 2.44 ab
Single 24" 7/19 6.9 17.0 25.7 b 67% 67.9 bc 0.422 a 2.03 b
Double 18" 7/20 5.2 16.1 25.5 b 64% 82.5 b 0.350 b 2.55 ab
Double 24" 7/21 7.6 21.9 33.9 a 65% 96.7 a 0.393 ab 2.60 a
* Early harvest through 8/2/06

37. Indeterminate Tomato Spacing Study
Cultivar-Cobra
Lbs/Plant Ripe Fruit Harvest
1st % # Fruit/ Lbs / Lbs/
Early* Ripe
Spacing Ripe Good Plant Fruit Sq. Ft.
2003
12” 8/8 0.1 9.6 59% 22.8 0.429 2.29
18” 7/28 1.1 11.8 58% 29.3 0.401 1.87
24” 8/1 0.6 15.8 72% 40.3 0.393 1.88
2004
12” 8/9 0.0 13.7 77% 32.7 0.419 3.26
18” 8/6 0.1 14.1 76% 34.6 0.408 2.24
24” 8/6 0.1 21.6 82% 43.6 0.496 2.57
* Early harvest through 8/2

38. Cobra Yield By Fruit
Category (lbs/sq. ft.)
Treatment Early Good Spoiled Immature Total
Single-18" 1.01 2.44ab 0.57 0.81ab 3.82a
Single-24" 0.82 2.03b 0.41 0.62b 3.06b
Double-18" 0.82 2.55ab 0.57 0.93a 4.04a
Double-24" 0.90 2.60a 0.57 0.86ab 4.05a

41. Pruning and Spacing
Tomatoes in High
Tunnels
Questions ??