The use of PGRs in ornamental cultures is likely to be more restricted in the near future. As an example, from March 2020 onwards, propiconazole will be banned in a lot of countries. BOL took on the challenge to test what is achievable with regards to growth control through growing media and feeding.
Up to 13% growth reduction is achievable in helianthus culture through substrate and feeding strategy. Image Demokwekerij Westland
Already in 2018 BOL has experimented with a special designed growing medium at various growers. A 10% growth reduction seemed to be feasible in the first part of the culture. However, the growth reduction did not always continue to the same extent towards the end of the culture. Possibly the feeding regimes that the trial growers had in place resulted in elongation in the second part of the culture.
As a trial with different feeding strategies is hard to execute in a commercial nursery, BOL, therefore, decided to test different feeding strategies at a research station. At Demokwekerij Westland 2 different growing mediums and 3 different feeding regimes have been tested on a Helianthus crop. In the trial no PGRs have been applied. This to have a clear view on the effect that the growing medium and the various feeding regimes have on the growth.
The results show that a special designed growing medium has an effect on the length of the crop. When used in combination with a special feeding regime a growth reduction of 13% was possible without use of any PGRs. There was no significant difference in flower size or branching between the various treatments.
Eric Forschelen, adviser at BOL, is convinced that with further fine-tuning of the substrate even more growth reduction should be possible: “We do not have the illusion that through the growing media PGRs are no longer required, but with this trial we have proven a certain growth reduction can safely be accomplished.”
BOL has also run a number of trials with growing media that give more compact growth at various pot and bedding plant growers during this spring season. A lot of data has been collected and the results are very promising. For one it has become clear that tailor-made solutions are needed for different crops.
BOL is a manufacturer and supplier of a wide range of growing media and substrates for professional growers. With 60 years’ experience, they know what is required to have a successful crop.
For more information:
J.C. Bol & Zn. B.V.
Nieuw Oranjekanaal 95
3151 XL Hoek van Holland
T: +31 174 51 7300
E: administratie@bolpotgrond.nl
https://bolpotgrond.nl/