'There is no such thing as a year without acid'

The Bos brothers in Wieringerwerf (NH) belong to the group of enthusiastic and passionate bulb growers. They like to talk about their profession and their way of working – which is sometimes different from the average. In addition to viruses, they are also quite keen on Fusarium. ,,A year without acid does not exist; we therefore have to keep a close eye on it'', says Jaap Bos.

Marco, Gijs and Jaap Bos have an arable and flower bulb business together in Wieringerwerf (NH). Every year they grow about 13 hectares of tulips, partly on rented land. The main types are First Class and Leen van der Mark. They also grow a handful of smaller (and newer) varieties. They also breed about 5,5 million bulbs every year.

The arable crops on the farm are: ware potatoes, sugar beet, chicory roots, carrots, grass seed and grain. Gijs is mainly involved in arable farming, Jaap and (son) Marco mainly in bulb cultivation.

We meet Marco and Jaap Bos in one of the sheds, together with Nico van Langen of CAV Agrotheek. They are looking at a recently purchased, second-hand planter that will be mounted behind the crawler tractor in the coming weeks. The planting machine – an oldie with at least 25 years of planting in its legs – is lightweight and therefore fits in well with the company's philosophy: on the land with as little weight as possible. Marco acknowledges that it might be easier to buy a standard machine. ,,But we have our own ideas about how to plant bulbs. And not unimportant: we like to tinker a bit'', he laughs.

Concerns about TVX and TBV
In the company canteen, the conversation soon turns to the fight against the virus in tulips and the associated challenges. Marco says that the company has had problems with the TVX virus in a number of parties in recent years. Fortunately, by tackling possible sources of smearing and paying more attention to industrial hygiene, such as the systematic disinfection of the sorting machine and the scalding container, the problems have become considerably less. ,,Hopefully we've got the right line now and we can keep it under control. We have become sharper anyway," said Marco.

In addition to TVX, TBV also demands constant sharpness and attention from the growers. This year, due to the cooler weather, less irrigation and a longer selection period, this virus seems to play a less prominent role than in previous years. But according to Nico van Langen, that does not alter the fact that it is a growing problem – seen over several years. “We have to take into account more warm summers in the coming years and therefore a higher louse pressure. In addition, fewer resources will be available to combat lice and selection work will come under increasing pressure due to ongoing scaling up. I therefore expect more problems with viruses."

Due to the disappearance of lice repellents and lice killers – as well as the decreasing effectiveness of pyrethroids, Van Langen likes to champion the use of mineral oil. Regardless of the weather, the addition of oil always works for around 80 percent. Pyrethroids are nowhere near reaching that percentage. You can be very happy if it works for 50 percent; often it is less. In my view, the use of oil is a must, especially for virus-sensitive species," says Van Langen. The Bos brothers have so far not worked with mineral oil and they are also a bit wary about it because of the stories about possible loss of yield. Van Langen, however, resolutely dismisses these stories. “The added value of oil has been clearly established in various independent tests in recent years. And even already would If mineral oil results in a loss of yield of a few percent, the benefits of less virus contamination far outweigh this."

'Less acidic than in other years'
After a second cup of coffee, the conversation shifts to Fusarium. Jaap Bos expects that the initial pressure may be less than in other years. ,,The harvest period may have been a bit on the wet side, but fortunately the temperature was also quite low then. In addition, the ground was quite soft this year, which resulted in relatively little damage. I therefore expect that the amount of acid will not be too bad; in any case below the multi-year average.” Marco adds that they have been quite 'economical' with drying this year, but that this is not yet reflected in the amount of acid. Nevertheless, father and son remain alert. “There is no such thing as a year without acid. And: sour planting is sour harvesting'', Jaap knows from experience.

The company has been using the Inflow foaming method for bulb disinfection since last year. To do this, they rent a machine from CAV Agrotheek – one of the companies that has launched and promoted this method in recent years. Although Marco points out some 'points for improvement' for the machine at Van Langen, he is very pleased with this way of disinfecting. “Inflow foaming is just as effective as dipping and showering, but you have virtually no leakage losses. It is precisely with regard to emissions – and in particular the peak loads to surface water – that we as a sector will have to become much stricter. Far too often I see boxes along ditches or field sprayers outside during rain showers. If we want to maintain the right to exist as a sector, we have to go to zero emissions'', says Marco. Nico van Langen fully agrees with these words and emphasizes that responsible behavior can also contribute to the conservation of resources. “Land runoff is by far the largest emission route. By applying Inflow foams we can make a huge difference'', is his conviction.

Choice of means 'ever easier'
According to Van Langen, the choice of means for bulb disinfection is becoming 'increasingly easier', because more and more products are being lost. ,,This autumn the authorization of the drug Topsin M® will expire and Mirage® Elan will also be banned next season. Both agents are now widely used in the bath; We have to designate smart replacements for that.” Van Langen sees a great role for this Rudis"A drug with a similar effect to Mirage, but slightly better because of its newer formulation," he says. Although many companies prefer to maintain a broad cocktail against Fusarium as a precaution, Van Langen argues in favor of fine-tuning per species. ,,In some species the emphasis is entirely on Fusarium, but some also on Rhizoctonia and other diseases. In my opinion you also have to look for the right means with added value'', he concludes.

More information?
Have a look at crop page 'Time for Tulips' for a complete overview of articles, recommendations, products and more.

^{Topsin M® is a registered trademark of Certis Europe
Mirage® Elan is a registered trademark of ADAMA}

This business case is powered by: