Maintaining progress in productivity with
Dazide ENHANCE
Holland, the powerhouse of European horticulture continues to
drive and, in some ways dictate, how the rest of Europe grows,
produces and sells its flowers and plants.
Among those exports, it's perhaps not surprising that the tulip
is no longer queen of the Dutch blooms. Instead, pick of the
pops are chrysanthemums, grown by nurseries such as
Zonnehoek in Kwintsheul. Zonnehoek is actually bucking the
trend of fewer hectares: their three hectares of glasshouses,
only six years old, it set to increase in size following the
acquisition of another site, and continued investment.
One particularly pertinent example in the ornamental market is
plant growth regulation. Where traditional flower wholesalers
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Short long day: The comprehensive
automatic system of blinds and artificial light
allows precise manipulation of flowering and
vegetative growth stages.
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might have been content with long stems, up to 75cm in
length, to allow for trimming and so on, today's supermarket
buyers - who in the UK account for 60 per cent of the cut flower
sales - dictate far more stringent requirements. They want stems
no longer than 65cm and there's very little room for variation -
which requires close attention to detail from Zonnehoek's Crop
Consultant Jon Krouwer. He makes a weekly visit to the greenhouse
to assess the crop and advise upon any necessary treatments. Each crop
is different, he says; so daminozide dose rates (in this case,
Fine Agrochemicals 'Dazide ENHANCE')
have to be tailored to suit. It's certainly clear how even small
differences in PGR use affect the plants growth. What's more, each
cultivar has to be 'learnt', how it responds to climate performance in the
greenhouse, and so on, with seasonal changes often exaggerating the difference.
For example, summer crops of Deliflor's Delianne spider cultivar can often
require up to twice the PGR dose rate of those grown in winter. With
Zonnehoek shortly planning to switch to the Anastasia cultivar, Jan will be
paying close attention to the first crops to see how the cultivar reacts
to changes in temperature, humidity and soil moisture.
That will provide the information needed to tailor daminozide applications:
how much to apply, and when to apply it.
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| Each crop has to be managed differently to get the
most out of growth regulation.
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"In Holland, greenhouse growers seem to demand a
far greater input from their agronomists than is
normally the case in the UK", says Wilbert Flier, Fine's
technical services manager based in the Netherlands.
"But the more regular visits certainly seem to pay off,
as both the agronomists and client have greater contact
and know more about crop progress and
development. "That's particularly important when using
a product such as Dazide ENHANCE, which many
growers see as an essential management tool", he
continues. "The compact growth bud formation that the
product encourages are precisely what the auction
buyers here in the Netherlands are looking for".
Zonnehoek complements the use of Dazide ENHANCE to fine-tune plant growth and
development with a comprehensive system of automated blinds and shades throughout the
greenhouses, which force the plants into 'long-day' and 'short-day' photosynthesis modes.
Chrysanthemums are naturally short-day plants: that is, they form their flowers only when
the day length is less than 12 hours. So by keeping the plants on a long-day regime,
the amount of vegetative growth can be controlled, before switching to short-day to force
the plant into flowering.
Article supplied by The Commercial Greenhouse Grower - April 2006