Speed of growth & development

By André Kool, GreenQ 10 February 2010

Speed of growth

“Speed”

Flower-Harvest approximately 6-10 weeks

Lightlevel/plantload determines 24 Hr-average. 24 Hr-average

determines speed.

Important for speed is optimal day-climateCold heads and a death

climate cannot be compensated by a warmer night

Speed of growth

Higher 24 Hr-averages with relative warm nights will result in:

• 1.slightly faster from flower to harvest (less then a week)

• 2.Higher risk of weak heads and trusses (quality problems in hot summers)

• 3.Smaller fruits (but kg’s not compensated by more trusses and fruits)

• 4.Higher risk of unbalanced growth (too vegetative) because of weak trusses & small fruits

• 5.Higher risk of hollow fruits

Speed of truss formation and balance

• Relation between speed of truss formation & temperature

Truss / week

24-hour-average in °C

0 16 17 18 19 20 21

1.2

1.1

1.0

0.9

0.8

Speed of truss-formation

Speed of truss formation and balance

• T higher =more trusses=more generative plant ?

• No, because truss & flower get weak when you grow to fast and too small fruits will not restrain (control) vegetative growth!!

Lightlevel/plantload/stem density temperature

speed

Speed of truss-formation

Speed depends on 24 Hr-average (see graph)

However it’s not only 24 Hr-average:Experiments at Naaldwijk Station showed already in 80’s

D 20.8- N 16.3- 24 Hr average 18.4 0.86 Truss/weekD 18.3- N 18.4- 24 Hr average 18.4 0.83 Truss/week

Speed of truss-formation

Other research did also find a 3-5% slower truss formation at relativehigh night- and low day-temperatures.

In growing practise we see similar effects with regard toripening of fruits:

“Speed” is more determined by……

day temperature

Speeding up fruitripening?

• Pulling leafs: more exposure to radiation of heating pipes / sun light

• Short leafs long leafs (see pulling leafs)

• Relative high day & low night temperature

• High night=dangerous high risk of “hollow fruits” and hardly faster fruitripening

Hollow fruits: a risk of warmer nights

Fast harvest: choice of cultivar

Big size beef tomatoes

first harvest when truss 8-10 is flowering.

Small size (cherrie, cocktail) tomatoes

first harvest when truss 6-8 is flowering

“Smaller size tomatoes are more early”

Questions?

Thanks for your attention!

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