Solarflex High Tunnel Films
For anyone not familiar with high tunnel films. High tunnel films have been in use in Europe since 1988. They were originally developed, in the United Kingdom, for open field raspberry growing, and have since been applied to many other crops. The first Haygrove high tunnels were built in Canada in 2002. It is a system that uses a greenhouse concept for growing crops but, in an open field system. Without the full expense of a greenhouse.
AT Films produces a series of products under the SOLARFLEX name that aid the tunnel grower in achieving higher total yields, by 30% to 40%. With a higher percentage of first quality produce, in some cases up to 85% and a longer growing season than is an achievable in the field. The length of the growing season is dependant on the earliness and severity of the winter weather. Consequently the extended growth period observed to date has varied from 2 months or more.
Because AT Films uses the toughest resins available Solarflex film on high tunnels will protect the crops from becoming damaged by rain, hail, wind, fall and winter weather, depending, again, on when the first severe frost occurs.
High tunnels due to their design combined with the Solarflex covering, allow non mechanized venting because of the open ended structure which aids in improving moisture control and thereby significantly reducing moisture related diseases such as botrytis, black spot, downey mildew, donolinia.
Controlling the type of light allowed through the polyethylene film with the use of specific additives also controls insects and pests. The film can also be designed to keep the light absorption to a minimum thereby making the film friendly to pollinators such as bees. The additives can diffuse the light which means the direct light is spread out as though it is coming from many angles. This does not reduce the quantity or the wavelengths of light coming through the film, nor does it reduce the amount of photo synthetically active radiation, known as PAR light, that is required for plant growth.
Allowing part of the ultra violet spectrum through the film also assists in controlling Botrytis or when all the ultra violet light passes through the film this can again positively affect the growth of some specific plants. Bees need a certain amount of ultra violet light to be able to see.
Other additives will reflect infra red light to prevent the tunnel from getting too hot during the day and any near infra red that becomes infra red as the temperature drops becomes reflected back into the tunnel to help retain the heat during the night.
The days for harvesting can be guaranteed as there will be no rain delays. Spraying can be performed when necessary independently of the weather. Less spraying would be required, compared to an open field, because the chemicals are being retained in the tunnel and not dispersed by the wind or rain.
The AT Films Solarflex tunnel covering is a 6mil polythene film that can be:
- Clear
- Diffuse
- Heat Retaining
- Bee Friendly'
- Totally UV Transparent
Albeit the Solarflex films can be produced in different forms the recommended and proven product is;
- AT Films DFSXT a film with additives that not only diffuse but prevent the “infra red” light from passing through the film. This has the effect of preventing the crops from scorching however, the “near infra red” is allowed through the film and gently heats up the tunnel. As the outside temperatures drop the “near infra red” loses energy and becomes “infra red” which is reflected back into the tunnel at night thereby retaining heat in the tunnel.
The following is a list of products now grown under high tunnels:
- Tomatoes
- flowers
- strawberries
- raspberries
- blackberries
- redcurrants
- blackcurrants
- cherries
- plums
- melons
- herbs
- nursery stock
- pot plants
- peppers
- chilies
- aubergines
- high value salad crops
- high value vegetable crops
- zucchini.