Henk in front of the practical screen system

Advisie Screen:
During the year 1999-2000 AdVisie has conducted research on the spreading of Verticilium on farms in the Netherlands. The aim of the research was to find a practical test for Verticilium, make practical handouts for the people on the farm and instruct them and to find practical solutions to stop the spreading of Verticilium.

The test was developed in cooperation with the Dutch research station. Selective media for petri dishes are made which can be used on the farms to test for Verticilium.  The handouts were made and given to all farms and to all organizations that have
people visiting mushroom farms. These forms were made for farmers, lorry drivers, pickers and all other people in the mushroom farms. The last part was to prevent spreading. It was found that infection at the moment of filling or casing was most likely and that it is caused by flies. This was the case when all the rest was taken care of.

During filling or casing the doors are open and flies leave the old rooms and are attracted by the smell of growing Phase III compost. We found out that they walked in over the walls of the tunnels or over the compost floor. In other cases they flew in and research showed that they flew at a low altitude (lower than five metres). Therefore we developed a system that could keep out flying insects and all dust.

Dust is also an important factor in the spreading of Verticilium.
Several ways were tested but water was the best solution and this way the AdVisie fly screen was developed. The water washes out the dust and the reflection of the light in the water keeps away the insects. The screen is a construction of pipes of
2.5 mm. Hanging in a frame of 4.5 metres high. One pipe covers the roof of the room that is being cased or filled. Together with the other 3 pipes it forms a square construction around the pile of compost or casing soil, closing in the area and the open
room completely. A bigger construction can be made (see photo) to close in the complete compost floor and the building.

This construction can be divided into sections.
Technical data:

Height of the construction: minimum of 4.5 meters so lorries can enter.

Length of water pipes: 20 metres maximum

Diameter of water pipes 25 mm.

Drill holes in the water pipes of 1 mm  every 4 cm.

Do not use nozzles because they cause drift and then the effect is gone.

Water pressure 1 to 1.5 bar.

Water consumption of the system 4 to 4.5 cubic metres per hour per 30 metres of pipe.

Strong construction to hang the pipes for safety reasons.

The water flow has to be started before the compost and casing arrives and before the room is opened.

During winter the construction is not needed.

Tests have proven that a farm with a  Verticilium infection can get rid of that Verticilium within three months, using the AdVisie fly. screen. These tests were conducted during the summer of 1999. A hot summer with a high density of insects
outside the farm. This can only be achieved however if the rest of the normal hygienic standard is maintained.

For more information you can contact:

AdVisie  
"the mushroom consultants"
Henk van Gerwen
Vondersestraat 44
5961 JR Horst "
The Netherlands
Mob. Phone. 0031 621842902
Fax. 0031773980427


AdVisie