Dutch rose grower Barry Brockhoff has been using NatuGro since 2014 with excellent results. 'NatuGro is here to stay; we'll never stop using it. We've seen nothing but progress.'
Brockhoff's adviser, Jan Hoogstrate from Horticoop, suggested he use NatuGro in 2014. 'Jan thought it was something for me. I'm always open to new things and took the right approach from the very start.'
Four test beds were created for a five-year crop at his 2.7-hectare company (which focuses on the cultivar Red Naomi), each of which is 880 m² in size (one watering system). These beds were used to test Vidi Parva, Vidi Fortum, Vidi Terrum, and Fortafol. The products were trickled onto one bed, sprayed onto another, and sprayed and trickled onto a third. The fourth bed was left untreated, as a reference.
Jan Hoogstate was pleasantly surprised when he visited the company. 'He said things were going extremely well,' explains Brockhoff. 'I knew what he meant; even I could see the difference. There were a lot more branches and longer branches as well, which means the overall yield was much higher.'
Of the three application methods, trickling proved the most efficient. 'This became our preferred method in 2015,' explains Koppert consultant Age Tanja. 'That was also the year we involved Koppert's NatuGro expert Dave Heij. The goal for Brockhoff, Horticoop, and Koppert was to fine-tune the NatuGro application method.'
The products were injected directly into each watering system and an injection point was installed in each bed. As a result, the mixing tub was no longer needed and the application method was much more precise.
Brockhoff Rozen used ten beds in 2016, one of which was left untreated. The other beds were used to individually test the NatuGro products. Veni-Prisma and Veni-Calcium were added to the test list.
Now, in 2017, NatuGro is being used on the entire garden and Brockhoff has come to some pretty clear conclusions. 'Compared to the untreated crops, I see nothing but progress. By far the biggest difference is in the beds where NatuGro is administered continuously, so where the products are applied in seven daily watering sessions instead of one big one.'
Mildew less severe
Another clear advantage is that Veni Prisma appears to boost the entire NatuGro system. 'We're still investigating how this works, but we do know that Veni Prisma enhances the effects of other NatuGro products,' says Tanja.
Brockhoff has also seen above-ground benefits to using an efficient crop supplement like NatuGro. 'The crops are stronger above ground as well. Mildew is far less severe now.'
The rose grower is at an advanced stage of using biological crop protection. Spider mites and whitefly are no longer a problem and thrips is kept in check with the help of Amblydromalus limonicus. The most troublesome pest is the mealy bug, which Cryptobug should help to keep at bay.
Brockhoff also consults his colleague Joop van den Nouweland in Waddinxveen on a regular basis. 'We keep each other up to date and we learn from each other.'
Moving ahead with Trianum
The successes of NatuGro align with Brockhoff's strategy to use as few chemicals as possible to grow a strong and high-yielding crop. Brockhoff plans to introduce Trianum this month and will attend a meeting with all other parties to determine how NatuGro products should be used next year. 'The question isn't whether we'll use them, but how,' according to Brockhoff and his employee Bart van de Wetering, who specializes in crop protection. 'We'll never stop using NatuGro.'