As part of its ongoing commitment to innovation in the field of plasticulture, Solplast has developed a photoselective antivirus/antiblackening film.
Most virus infections that occur inside greenhouses are propagated by insects, such as the silverleaf whitefly (Bemisia Tabaci), which act as vectors, carrying the disease from one crop to another. The visual capacity of these insects lies within a range of radiation between 290 and 380 nm (UV-B). If a screen is installed that prevents this radiation from penetrating the greenhouse, these insects will become disoriented and their activity will diminish. This inhibits their effects in the form of plant diseases.
This screen is created with the antivirus film manufactured by SOLPLAST S.A., which uses a combination of photoselective additives to prevent UV-B radiation from penetrating inside the greenhouse, causing the insect vectors to become disoriented, as described above. It is important to keep in mind that blocking this radiation may negatively affect beneficial insects in the greenhouse (such as bees and bumblebees used as polinizers), since they will also become disoriented. Tests conducted by SOLPLAST S.A., in collaboration with the University of Almería, indicate that bumblebees are able to adapt to this situation.
It is also possible to compensate for this difference by placing more hives inside the greenhouse. The abovementioned tests conducted by SOLPLAST in the region of Mazarrón and Almería on tomato crops demonstrated 50 to 70% reductions in the activity of the silverleaf whitefly. In terms of the bumblebee activity inside the greenhouse, it was observed that after a while, they adapted to the decreased radiation caused by the antivirus film. It was also observed that by adding 50% more hives, the bumblebee activity returned to previous levels.
In addition, it was also demonstrated that UV-B radiation is responsible for the sporulation of certain pathogenic fungi, such as Botrytis Cinerea. By blocking this radiation, the sporulation process of this fungi is inhibited, halting its development at that point.
Furthermore, UV-B radiation is also responsible for the over-pigmentation (blackening) on the edges of the petals of certain dark-colored varieties of roses, to the extent that they appear almost black, which reduces their market value. By preventing this radiation from penetrating inside the greenhouse, there is a decreased risk of the appearance of blackening.
It is important to keep in mind, however, that UV-B radiation is responsible for fixing of color pigments on the light-colored varieties, and thus the use of this type of film would be ill-advised in some cases.
- Mechanical properties: high tensile strength, impact resistance and tear strength.
- Optical properties: good transmission of visible light, which permits the heating of the growing area, favoring photosynthesis and subsequent plant development.
- Excellent light diffusion: prevents areas of shade inside the greenhouse, homogenizing the light throughout the entire growing area, thus reducing irregular development.
- Optimal heat-insulation effect: the combination of its IR additives creates a barrier against long-wave infrared radiation emitted by the soil at night. This prevents sharp temperature drops, eliminating the risk of thermal inversion and keeping the greenhouse temperature a few degrees warmer than outside.
- Photoselective effect: highly resistant to degradation from both sunlight and chemical treatments applied inside greenhouses.