MXPA00004383A - A plastic film for use in agriculture - Google Patents

Abstract

The invention provides a polymeric, multilayer, photoselective film for use in agriculture, comprising at least two layers, an upper layer facing the sky and a lower layer facing the ground, each of the layers being of a different color, and each being light-transmissive, wherein the upper layer is of a color which repels insects, and the lower layer is of a color whereby the solar radiation transmitted by the film and reaching the ground is of such a spectral composition as will largely deprive weeds of essential photosynthetically active radiation, while having a spectral component that will be absorbed by, and will heat, the ground.

Description

A PLASTIC FILM FOR USE IN AGRICULTURE Technical Field The present invention relates to a mulch film for use in agriculture. BACKGROUND ART The use of mulch films, that is, plastic films dispersed along the ground and provided with holes for sowing the seeds or planting the shoots, is well known in agriculture. Its purpose is to promote the growth of the plant by ensuring favorable growing conditions, such as increased soil temperatures, as well as reliable control of the herbs without the need for herbicides. This way of influencing the environment of the plant is possible by manipulating the properties of reflection absorption and transmission of the mulch film. Such a film is known from European Patent Publication No. 0398243, some of the teachings of which are incorporated herein by reference. Although, due to photoselective transmission, the green film according to said publication provides a useful response to the aforementioned problems, the subject matter does not attack the important problem of effective protection against insects that are vectors of various diseases plants and require the application of agrochemical products and / or networks for insects. Agrochemical products carry the environment and networks for insects reduce the yield of the crop, due to its reduction of light transmission. DESCRIPTION OF THE INVENTION It is thus one of the objects of the present invention to provide a mulch film that not only warms the covering earth and substantially reduces the growth of herbs, but also acts as a repellent with respect to insects, many of which act as vectors of disease, building this property on photoselective reflection of light. According to the invention, the above object is achieves by providing a multi-layered, polymeric photoselective mulch film for use in agriculture, comprising at least two layers, one upper layer towards the sky and one lower layer towards the earth, both light transmitting layers being where the top layer is one color substantially yellow and the lower layer is of a substantially blue color, whereby the solar radiation transmitted by said film and which reaches the earth is substantially in the green and farthest red of the solar spectrum, depriving the grass of radiation essential photosynthetically active and the component is red : < A far away, absorbed by, and warming, the earth, and through which the yellow color of the upper layer serves to repel insects that act as vectors of plant diseases. The invention further provides a crop culture method, comprising the steps of providing a multi-layered, light-transmitting mulch film, one of whose layers is yellow and the other is blue; extend this film along the earth with the yellow layer towards the sky and the blue layer towards the earth and provide holes conveniently separated in said film or use pre-prepared holes in said film for seeding seeds or planting shoots. Detailed description The film proposed by the invention is a Two-layer light transmitting film, stabilized for ultraviolet, preferably produced by the coextrusion of any of the commercially available polymers (polyethylene and its copolymers, PVC, etc.), with one layer of a substantially yellow color and the other layer of a color substantially blue. Together, these two layers transmit approximately 15 to 30 percent of the solar energy in the green range, with a maximum of approximately 0.56 μ. They also transmit in the far red region between 0.75 and 1.1 μ. The film thus filters out a large part of the radiation photosynthetic active (PAR), thus reducing in Greatly the growth of the grasses which is impeded by the absence of photosynthetically active radiation, at the same time that it passes to the far red, thus heating the earth. The characteristic property of the mulch film according to the invention resides, however, in the fact that the yellow surface of the upper film layer is known to repel insects and probably act as vectors for various plant viral diseases. The method for using the mulch film according to the invention is as follows: The film extends along the ground with the yellow surface towards the sky, and conveniently spaced holes are prepared (or holes are used previously). preparations) to plant seeds or plant shoots. The mulch film according to the invention originates in a coextruded tube or hose, which is cut to open longitudinally to produce the film. However, it is very possible to avoid the cutting stage, fill the tube with soil, close it at both ends and provide the aforementioned holes for planting and planting. The region of the tube with holes will still serve as a mulch, and these "mulch tubes" could be used in regions with poor soil. Although the green color mentioned above of the light transmitted by the two layers gives excellent results, ^ * * "t; ^ a > ^? s ~" ° ~ & i3a___ s_¿-- ^ J ^ Z ^ Sm ^ Favorable results are also obtained with transmitted light of violet, orange and brown colors. It will be apparent to those skilled in the art that the invention is not limited to the details of the embodiments illustrated above and that the present invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore considered in all respects as illustrative and not limiting, the scope of the invention being indicated by the appended claims instead of the foregoing description, and all changes that fall within the meaning and range of equivalence of the claims are therefore intended to be incorporated therein.

Claims (8)

1. A polymeric, multi-layered, photoselective film for use in agriculture, comprising at least two layers, an upper layer towards the sky and a lower layer towards the earth, each layer being of different color, and each a light transmitter; wherein the upper layer is of a color that repels insects, and the lower layer is of a color by means of which the solar radiation transmitted by said film and which reaches the earth is of such a spectral composition that it will deprive the herbs of radiation photosynthetically active, at the same time that it has a spectral component that will be absorbed and will heat the earth.

2. A multi-layered, photoselective polymeric mulch film for use in agriculture, comprising at least two layers, a top layer towards the sky and a lower layer toward the earth, both layers being light transmitters; wherein the upper layer is of a substantially yellow color and the lower layer is of a substantially blue color; whereby the solar radiation transmitted by the layer and reaching the earth is substantially in the green and far-red range of the solar spectrum, where the green component deprives the herbs of photosynthetically active essential radiation and the far-red component is absorbed and warms the earth; and by which the yellow color of the upper layer serves to repel insects that are likely to act as vectors of plant diseases.

3. The mulch film as claimed in claim 1, wherein the two layers are co-extruded.

4. The mulch film as claimed in claim 2, wherein the green component has its peak at a wavelength of 0.56 μ, and the far red component covers the range of 0.75-1.1 μ.

5. The mulch film as claimed in claim 1, wherein the colors of the two layers are such as to produce a transmitted light of a color selected from the group including violet, orange and brown.

6. The mulch film as claimed in claims 1 and 2, used in the form of a tube.

7. A method of cultivating crops, comprising the steps of: providing a multilayer mulch film, light transmitter, a layer of which is of a color that repels insects, and the other layer of which is a color by which the solar radiation transmitted by said film and which reaches the earth is of a composition ? > . . J_ * spectral such that it deprives the herbs of photosynthetically active essential radiation, at the same time that it has a spectral component that will be absorbed and will heat the earth; extend this mulch film along the earth with the layer that repels insects towards the sky and the other layer towards the earth, and provide conveniently separated holes in the film, or use holes previously prepared in the film, to sow seeds or plant shoots.

8. A method for cultivating crops, comprising the steps of: providing a multi-layered mulch film transmitting light, one layer of which is yellow and the other blue; extend the mulch film along the earth with the yellow layer towards the sky and the blue layer towards the earth, and provide conveniently separated holes in said layer, or use pre-prepared holes in the film to sow seeds or plant shoots.