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Hygiene: top priority in Roselily greenhouse

Growing a healthy crop of lilies seems more of a challenge than ever.

Hygiene: top priority in Roselily greenhouse Growing a healthy crop of lilies seems more of a challenge than ever. The chance of a virus infection makes it essential to start out clean and prevent these risks. But how do you do this? The ten Roselily growers invested in a virus-free greenhouse that operates according to a strict hygiene protocol.

First ring the doorbell, then cross the doormat impregnated with disinfectant, and then wash your hands. Not until you follow this procedure may you enter the Roselily complex in Breezand. The protocol for the greenhouse is even stricter. Ronald Timmer, the greenhouse manager, is one of the few with a key to access the airlock where you have to don white overalls, boots and overshoes. Even then, the only ones allowed in are an advisor or inspector for ‘a necessary visit’, according to Timmer. Clearly, everything here revolves around excluding the possibility of spreading disease.

For the members of Coöperatieve Kwekersvereniging ‘Roselilies’ U.A., these efforts are all about the production of disease-free planting material. The increasing risk of a virus infection – namely PlAMV – meant the need to speed up the search for a virus-free greenhouse. The basis for this was found in the form of greenhouses formerly used by Ronald Timmer to grow flowers. First, however, the place had to be made free of viruses. “The boiler was removed because the greenhouse would not be used in the winter. Next, insect screens were installed in all the vents and the greenhouse was equipped with an entry airlock to prevent air from being transferred into the tissue culture greenhouse.” After these alterations, the entire Roselily complex was disinfected. “We repeat this process every year as close as possible to the planting season. This is also accompanied by washing and steaming all the containers with a mobile system. Steam kills everything. This process also includes steaming the support surfaces in the greenhouse and all of its heat-resistant materials. The machinery is also disinfected during the planting and processing that follows each change of lots.”

A testing greenhouse
Roselily was very much aware of the need for a separate area for conducting extensive tests on its Roselily cultivars. “We want to know as much as we can about a variety before we start propagating it. This way, we hope to be able to estimate its marketing potential as soon as possible.” At this time, more than twenty cultivars are planted in the testing greenhouse: commercial varieties and potential new cultivars such as Roselily Aisha®, Roselily Leona® and Roselily Samantha®. “All the bulbs we plant in the testing greenhouse are saleable bulbs that have been produced under virus-free conditions. Short lines of communication are important.”

Virus-free stock
Roselily has virus-free stock available in its tissue culture greenhouse. These are the bulbs smaller than size 5 that were not scaled the year before. “We can rely on these for scaling at any time. If we didn’t have this resource, we would have to start back at square one with tissue culture: an expensive and time-consuming process.” The ‘under 5’ bulbs are planted first and then the tissue culture material. The planting period runs from March to June. “The last to be planted are the bulbs on scales that were produced last year from tissue culture and are larger than bulb size 8. All material between these sizes (bulb sizes 5 to 8) is planted in a field at one of the Roselily grower’s locations dedicated exclusively to the growing of planting material in order to avoid contact with previous lots. Roselily works closely with Aad Prins for advice on the technical aspects of cultivation. Obviously, all of this involves a considerable financial investment. “Roselily is convinced, however, that this will result in quality, reliability and stability that will offset these extra costs. Losses caused by disease that turns up later in the lots would involve even higher costs.” Hygiene is the key.

About Roselily
Coöperatieve Kwekersvereniging ‘Roselilies’ U.A. is a cooperative growers’ association that was founded in 2008 for professionally propagating double-flowering lilies developed by De Looff Lily Innovation and marketing these products together with CNB and its buyers. Affiliated with this growers’ association are ten companies in the northern region of the Province of North Holland: Boltha bv, Harm Peter Duineveld, Gouwenberg, Fa. W.W. van Haaster & zn, Kesteloo Bloembollen bv, fa. J. Th. Kreuk en Zn, W. Th. Langelaan en Zonen bv, W. van Lierop & Zonen bv, Meelébo bv and Westend Bulbs bv.

Source: Bloembollen Visie
By: Jeannet Pennings
Photography: René Faas