1. Plant balance and crop steering By André Kool, consultant Green Q

2. Index Plant = factory Roots, Irrigation, Substrate
Fotosynthesis, LAI, CO2
Climate
Crop planning

3. How does the plant grow? Radiation CO2 (plant) temperature Feeding
humidity
Water

4. Plant = factory Head = new development, future
Leaves = factory producing assimilates
Stem = pipeline (logistics)
Roots entrance = mouth of the plant
Fruits = storage of assimilates

5. A strong root system Plant Roots Substrate Water management
Stimulate root growth to absorb optimal water and
fertilizers.

6. Water management Start time Stop time Shot lenght
Decrease of water content
Amount of gift and drain
EC drip and drain
pH drip and drain

7. Water management before planting on hole
Nursery / next hole
Stategy for 10 x 10 cm blocks ( 1 plant per block)
Before flowering first truss block weight g.
When flowering slightly more water ( g)
100 cc irrigations per block
Sometimes (frost, hot pipes) night irrigations are required
EC may raise from 2.0 up mS/cm but no lack of water!!!!!

8. Planting on hole (rooting)
When truss 1 is flowering/first flower of truss 2 starts to flower
During rooting in slab (+/-some days) more water to maintain contact slab-block
Roots can take water from slab? Reduce water!!!
Control period starts

9. After rooting
After rooting plants reacts “vegetative” (stem gets more thick)
“Generative” steering with water (and climate: more “active”)
Reduce gradually humidity slab (f.e. 9575%)
Measure weight and / or humidity
Guideline is 1% weight per day during 3 weeks
Low drain% 0-5%
EC slab rise up from +/- 3 to 5.0 max 6.0 mS/cm
After truss 3 and 4 are flowering, fruitload will start to limit vegetative growth
After control period back to “normal” irrigation strategy

10. After rooting
Dangers of generative steering by too less water (especially at high EC)
Dry+high EC= Magnesium deficiency symtoms (first in old leafs)
Dried flowers
Pythium (especially when humidity changes from wet to dry and reversely)
Weight scales can be helpful equipment!
Keep always looking to color flowers and plant

11. Night shot when decrease of water content is too big
Water management after control period (“normal” irrigation stategy)
Start time
after 100 J – 150 J
2-3 hour after sunrise till hour before sunset decrease of water content
Rockwool %
Cocopeat %
Night shot when decrease of water content is too big
reducing root pressure

12. Shot length Big shot  bigger break  dryer slab > generative
Small shot wetter slab > vegetative
Optimal shot length calculation:
2 - 5% of slab volume
Calculation and registration per m²

13. Decrease of water content

14. Weight scales & drain measurement

15. Decrease of water content slab
How is the calculation?
Big decrease  dryer > generative
Small decrease  wetter > vegetative

16. Drain and gift amount Amount of gift 2 – 3.5 sum of radiation
depends of stage of the crop
Time of first drain
30% total drain
Drain per shot

17. Drain (adult crop in summer)
2.5 * Joules
3.5 * Joules
40-50% drain
10-20% drain
Start
First drain
3 hr before stop
Stop

18. EC Drip and drain High EC > generative Low EC > vegetative
Depends on evaporation, higher in winter time
Influence slab / drain EC
Drip EC
Decrease of water content
Amount of drain
Shot length

19. pH drip and drain pH drip between 5.2 – 5.5
pH in slab between 5.5 – 6.2 for optimal uptake elements
Low Phuptake of positive ions
High pH uptake of negative ions
Steer the pH in root environment:
Ammonium nitrate based on pH & HCO3-level
Ureum based on pH & HCO3-level

20. Equipment to control Weight scale Humidity measurement Extra checks
- measuring EC / pH / drip-drain amount

21. Substrate Cocos in opposite of Rockwool: Higher decrease of water
content
Bigger shots
Higher drain EC

22. CO2 + LAI

23. Fotosynthese
Light suplies energy to transform CO2 + H20 into the leave to sugars

24. Production tomato (kg/m2)
Total plantgrowth (biomass production)
Leaf fotosynthesis
Light interception
Fraction to fruits (Biomass distribution)
Amount of fruits x potential fruit size

25. Leaf Area Index Optimum for summer between 3 - 4
This means 3 - 4m² leaves per m² floor
Average 16 leaves = 1m² LAI
LAI of 3 means 50 leaves per m²
Higher greenhouse, more light, needs higher LAI

26. Depending factors on optimum LAI
Plantload per m²
Amount of light
Time of the year
CO2 level

27. April 75 fruits per m² 36 leaves 1200 J
Plantload related to LAI truss small beef (Admiro, 170 gr) traditional greenhouse 100 kg CO2 / hour admiro
Density: 3.1
April 75 fruits per m² 36 leaves J
June 100 fruits per m² 48 leaves > 1600 J
August 85 fruits per m² 42 leaves J
September 60 fruits per m² 15 leaves, top is out

28. High modern greenhouse
10 % extra transmission > 10 % more density
More CO2 5 – 10 % extra density
For strong variaties lower density
Generative and open variaties higher density
Climate  Leaf lenght

29. Temperature strategy tomato & balance
AN,SR too cold:
-short internodes
-long leafs (rootpressure and low HD)
-fat head
-purple head
-too strong flowers
-pollination problems
Peak too cold:
-chlorosis (too less transpiration)
-short internodes
-pollination problems
PN too cold (in relation to plantload and lightconditions):
-fat, purple heads
-too strong trusses/flowers
Peak too warm:
-length internodes:
1.Fast-Slow rise to peak
2.High-Low T-pipe
3.High-Low HD
-short leafs (at high HD)
-weak truss
-pollination problems
AN,SR too warm:
-long internodes
-thin head, weak truss
-short leafs at high HD(dry air)
-long leafs at low HD
-hollow fruits
PN too warm:
-thin weak heads
-weak trusses & flowers
-small tomatoes
-hollow fruits
-too long leafs

30. CO2 efficiency 1500 x 1000 / CO2 x CO2 = effect From 350 to 450 ppm
1500 x 1000 / 350 x 350 = 12% extra growth
From 1000 to 1100ppm
1500 x 1000 / 1000 x 1000 = 1.5% extra growth

31. Light interception makes a difference
Bron: Nederhof

32. Artiplant
Artiplant
Measuring light on different levels in the crop

33. Increase of light interception
1.60
1.92

34. Advantages of removing top leaves
Better penetration of the light to the lower level of the plant (more activity)
More assimilates to the fruits
Higher production till 10% is possible but the total LAI must be high enough, be carefull with deleafing at the bottom of the plants

35. Effect of removing ( top leaves) 10% more production is possible

36. Disadvantages of removing top leaves and too open plants
Too low total LAI, reduction of production capacity
Too high radiation on young fruits, white fruits, hard skin, splitting fruits

37. How does the plant grow? Radiation CO2 (plant) temperature Feeding
humidity
Water

38. Functions Head = new development, future
Leaves = factory producing assimilates
Stem = pipeline (logistics)
Roots = entrance, mouth of the plant
Fruits = storage of assimilates

39. Principle Leaves with light and CO2 produce assimilates
Assimilates can be used for:
*Further development of the factory
*Storage in fruits
“Growing is creating the right balance in this process”

40. Good balance 30% for plant 70% for fruits
More to the plant means strong and nice plants but to low yield
More to the fruits means high production for the short term but on the long term the plant will be weaker and weaker till the factory is totally destroyed

41. Balance plant & light Example: the total light is 1200 units per m² 3
Heads per m2 3 4
Light per head
400
300
For maintencance
120
For fruit
280
180
Light for the fruit per m2
840
720
Production
100%
86%
Difference 0%
-14%

42. Tools to keep balance Density of plants and LAI Temperature Light CO2
Water and fertilizers
Mechanic
Variety, grafting

43. Density and Light A good base is 50% of the job
Grow with a plan and a strategy
The optimum system depends on the targets of the producer
There many ways to grow tomatoes
Successful growing is just making as less mistakes as possible

44. The GreenScheduler experience
crop
density
global radiation
flower speed
artificial light
fruit size

45. The GreenScheduler Light conditions Balance Variety Crop density
planning
Load and
production
Result

47. Light - Temperature
Available light is the limiting factor in most cases
High radiation (600 Watt) gives extra generativity
With density, temperatures,CO2 and irrigation we can anticipate on this fact
The optimum temp range for tomato is between degree °C

48. DIF
Difference between day and night temp has big influence on the character of the plant
A big DIF gives a greater development on the fruits relative warm day, relative cold night
A small DIF gives a greater development to the plant relative cool day, warm night

49. Climate influence

50. Generative or vegetative?
How can I recognize the condition of the plant?

51. Same greenhouse, same varytie: where are the most and biggest tomatoes
Same greenhouse, same varytie: where are the most and biggest tomatoes? Left or right?

52. Weak

53. Generative

54. Fast and strong fruitsetting

55. Condition of the plant Generative Vegetative Condition head Flat Round
Flowering height
Height
Low
Truss position
Upwards
Bending truss tip
Bent
Straight / upwards
Position flower knot
Size of flower knot
Thick
Thin
Truss stem
We have the generative items for the condition of the plant and the vegetative items for the condition of the plant

56. Condition of the plant Generative Vegetative Flower colour
Bright yellow
Pale yellow
Setting
Strong
Weak
Swelling fruits
Plant balance
Fruits
Leafs
Leaf length
Short
Long
Leaf volume
Open
Full
Virus image head
Much
Less

57. Condition of the plant
Powerful or
Weak

58. Too strong

59. Weak

60. Condition of the plant Powerful, strong Low speed Powerless, weak
High speed
Condition head
Powerful, thick
Powerless, thin
Anthocyaan / purple
Much
Less
Virus image head
Internodes
Short
Long
Crop colour
Dark
Light
Stem
Thick
Thin
Setting speed
Low
High

61. Condition of the plant Powerful, strong Low speed Powerless, weak
High speed
Plant load
High
Low
Leaf length
Stretched
Compact

62. Mechanic ways to manage the crop
Removing top leaves
Deleafing strategy
Truss pruning
Clipping or twisting

63. Varieties - grafting Combination rootstock, variety
Amount of tops per rootstock depends power in the crop

64. The start

65. During the crop

66. Not bad

67. New start interplanting

68. Plant balance local light levels= crop planning
Analyze light conditions before you start and work it outGreen Scheduler crop planning program
Every area in the world and every season has his own specific climate and light curves
So experience is very usable and valuable, but a 1 to 1 copy from place to place is not per definition successful

69. crop planning Crop planning
In the winter and spring we have to keep the crop open enough and density is often too high
In the summer we need enough power and LAI to survive
In autumn we need an open crop again….
crop planning

70. Grow with a plan with clear and realistic targets
Density
Speed of the crop
Production per week
Fruit size
Quality
Length and period of the crop
Green Scheduler crop planning!!

71. Other important factors
Availability and quality of labour
Technical possibilities
“Green management” capacities
Eliminate risks
Keep it clear and simple

72. Thank you for your attention!