HU200253B - Method for increasing the yield of agrarian cultures by applying of hydrogels - Google Patents

Abstract

Field of the Invention The present invention relates to a method for increasing the yield of agricultural crops, such that, during the life cycle of 40% of the green weight of the plants, preferably flowering! by the end of the period, a hydrogel of 5 to 500 times the swelling capacity, capable of absorbing water and discharging water at a rate of 0.5-20 kg / hectare per treatment, is applied one or more times per treatment, optionally with 1-10 kg / ha of liquid non-oxidizing hydrocarbon oil and / or or oily aliphatic alcohol. EN 200253 A Scope of the description: 4 pages without drawing -1-

Description

FIELD OF THE INVENTION The present invention relates to a method for increasing the yield of agricultural crops by applying 0.5-20 kg per hectare of dry matter per application one or more times during the life stage of the plants to 40% of the green weight, preferably one or more times until the end of the flowering period. a hydrogel with a swelling capacity of 5 to 500 times, with an optionally 1 to 10 kg / ha of liquid non-oxidising hydrocarbon oil and / or aliphatic alcohols, is applied.

HU 200253 A

Scope of the description: 4 pages, without drawing

HU 200253 A

The present invention relates to a method for increasing the yield of agricultural crops using hydrogels.

It is known that the water demand of plants varies significantly depending on their state of development. After the development of 40% of the green mass, there are critical periods in the life of all plant species, when plants are more sensitive to persistent water scarcity and water scarcity can lead to severe damage to plants, developmental defects, and sometimes plant death. For cereals (such as wheat and barley), the critical period is the post-emergence stage of the flag leaves and then the grain formation stage. If the plant does not get enough water during this period, its stem growth will be suppressed, the ears will be smaller and the grain crop will be suppressed because grain filling is hindered. In the case of maize and sunflower, this critical period is the flowering stage. If the plants suffer from water shortage during the pollination (fertilization) period, the pollen tube is damaged and fertilization is delayed, resulting in a loss of yield.

Plants' water requirements can be met by irrigation, but irrigation is expensive and in many areas there is not enough water available for irrigation. In periods of drought, when the level of natural waters diminishes significantly, it is particularly difficult to provide irrigation water,

The amount of water needed for plant life has been tried indirectly by suppressing evaporation through the leaves. One such method is to apply hydrocarbon-type wax-like substances to the foliage. The disadvantage of this method is that the evaporation reduction coating thus produced has a long-term effect, even if the vegetation would have to be intensively evaporated for faster growth and development due to favorable weather conditions. In this case, the method is already disadvantageous and inhibits the development of plants.

Plants have a natural source of water, dew, even in the warmest of times. On clear, windy nights following warm days, the air cools down, and when it reaches the dew point, the moisture in the air condenses on the vegetation in the form of tiny drops of water, and then the dew drops fall to the ground. Dew formation is particularly abundant on nights after hot days. However, due to the rapid warming up of the day, the dew evaporates very quickly, so although some plants have been biologically modified to absorb dew (eg, through the dew roots of the grape, they can absorb the dew that has fallen on your heads). So there is a need for a method; whereby dew evaporation can be delayed according to the plant's biological needs.

In our experiments, it has been found that the evaporation of dew can be greatly retarded and the dew can be bound in a form that can be absorbed by the plant over a longer period of time by hydrogels formed from water-soluble polymers capable of reversible uptake and release of plant leaves.

It is known that most natural or synthetic polymers can be crosslinked to produce a hydrogel [R. L. Davidson, M. Kittig, Water-Soluble Resins (Reinhold Publishing Corp., New York, 1962), R. L. Davidson, Handbook of Water-Soluble Gums and Resins (McGraw-Hill, New York, 1980)]. These hydrogels have a high degree of reversible uptake and release of water, depending on the crosslinking density; they can absorb 2-500 times their own dry weight. These types of hydrogels are used in gel chromatography (T. Kremmer, L. Boros: Gel Chromatography, Technical Publisher, Budapest, 1974), for the preparation of microcapsule formulations, for drug formulation, and the like. '

It is known that some special hydrogels are capable of controlling the water balance of soils. Such a commercial product is Acrylhope (manufactured by Nippen Shokubai Kagaku Kogyo Co. Ltd., Tokyo, Japan). However, these gels have not yet been used to treat foliage in plants. Because of the reversibility of water uptake and dewatering, it was to be expected that when these gels were applied to the leaves of plants, the gel would bind water drops during night dew formation, with a high moisture content. It was also expected that the gel would clog much of the respiratory pores of plants and thus, like dust contaminants, inhibit the biological life of plants. Our practical experience is the exact opposite. In our experiments, we found that hydrogels capable of reversible uptake and release of water do not transfer the majority of the dew they bind to drier air, but rather to drier plants, and during periods of critical drought, they develop dew provide the plants with an additional amount of water equivalent to about 5-15 mm of precipitation. No damage due to dust contamination was observed in the plants treated with the appropriate treatment; treatment with hydrogels resulted in a yield increase of 10-20% on winter wheat compared to the control.

HU 200253 A

The invention thus relates to a method for increasing the yield of agricultural crops by improving water uptake. In accordance with the present invention, the above-ground portion of the plants is 0.5 to 20 kg / hectare, preferably 1 to 10 kg / hectare of dry matter per application, one or more times during the life cycle after the development of 40% of the green mass, preferably up to the end of the flowering period. an appropriate amount of a reversible water uptake and drainage hydrogel (prepared by reacting a water soluble polymer in an aqueous solution of 0.01 to 10 wt.%, preferably 0.1 to 5 wt.%, to determine the amount of cross-linking agent. an amount of the polymer to form a hydrogel having a swelling capacity of 5 to 500 times, and then the water-soluble polymer in an aqueous solution of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, before, during or after application to the plant. reacting with the amount of crosslinking agent so determined and, if desired, carrying out the reaction on the gel before, during and / or after application of one or more agricultural chemicals, preferably foliar fertilizers and / or pesticides) in the form of a dry powder or water-containing hydrogel.

By "swelling ability" is meant that it is capable of absorbing water in an amount equal to a multiple of the dry weight of the gel for 48 hours at 20 ° C in distilled water.

The swelling capacity of the gel is preferably 20 to 100 times.

In a preferred method, treatment with hydrogel is combined with treatment with waxes known in the art. In this case, prior to applying the powdered hydrogel (i.e., xerogel) or during application of the water-containing hydrogel (e.g., mixed in the hydrogel), 1-10 kg / h of a 18-36C liquid non-oxidizing hydrocarbon oil and / or Aliphatic alcohols containing 20 carbon atoms are also applied to the above-ground parts of plants. These oily materials include, for example, paraffin oil, cetyl alcohol, hexadecyl alcohol, octadecyl alcohol, dodecyl alcohol, 2-ethylhexanol and the like.

The applied oily substances can, on the one hand, promote adhesion of the hydrogel or xerogel to the treated surface and, on the other hand, reduce evaporation through the leaves of the plants, thus improving the utilization of water during the drought period.

Examples of water soluble polymers include polyacrylamide, hydrolyzed polyacrylamide, acrylamide copolymers, acrylamide-grafted starch and other polysaccharides, acrylonitrile-grafted and partially hydrolysed polysaccharides, and polyvinyl alcohol, water-soluble derivatives and copolymers. These are cross-linked by known methods, such as mono- or polyvalent aldehydes (such as formaldehyde, furfural, glyoxal or glutoraldehyde), to carboxyl-containing polymers with variable valence metal salts (such as calcium, magnesium or iron salts). Preferably, boric acid or borax can be used to cross-link the polyvinyl alcohol and its derivatives.

Preferably polymers having an average molecular weight greater than 20,000 are used. Polyacrylic ·? The molecular weight of the amide and its derivatives is preferably from ^{5 to 5} · 10 · ⁷ · ⁷ , and the molecular weight of the polyvinyl alcohol and its derivatives is preferably from 3 to 10 ⁴ to 3 to 10 ⁵ .

If necessary, the hydrogel formed during the crosslinking of the polymer can be converted into an xerogel powder by careful drying and grinding. If this xerogel powder is used for the treatment of the present invention and the gel powder is sprayed onto the wet surface of the plant, the granules will swell and adhere to the surface of the plant. The adherence of the gel particles can be enhanced by various additives, i.e., gel softeners. Adhesives which may be used include, for example, urea, glycerol, ethylene glycol and homologues thereof. They may be present in an amount of 1-100% by weight, preferably 3-20% by weight, of the xerogel.

The size of the xerogel particles may be from 0.01 to 1 mm, preferably from 0.03 to 0.3 mm. To further promote xerogel adhesion, the plants may be sprayed with an aqueous emulsion of hydrocarbon oils or an aqueous emulsion of alcohols prior to application of the xerogel.

The water-containing hydrogels are sprayed in the form of small droplets onto the above-ground parts of the plants. Water-containing hydrogels usually adhere well to the treated surface and can therefore be applied to dry plants. However, if desired, water-containing hydrogels may be treated with tackifying agents and / or the hydrocarbon oils or aliphatic alcohols listed above.

In the treatment according to the invention, the xerogels or hydrogels can be applied, if desired, together with agrochemicals, such as plant growth regulating, fungicidal and / or insecticidal agents or fertilizers. These agrochemicals can be incorporated into xerogels or hydrogels (sometimes incorporated into the gel structure itself), but can be applied to the plants separately, before, after, or in parallel with the application of the gels.

The invention is illustrated in detail by the following non-limiting Examples.

Example 1

Off-road vehicle Beren-35 for liquid fertilizer application

EN 200253 A 3.5 m ³ 2 wt.% Nonionic polyacrylamide solution (average molecular weight: 3-10 ^{4 * 6} ) was added to a 4 m ³ container of treatment and 350 liters of technical grade 87% glycerol was added as a tackifier. added. The mixture was dissolved and carefully homogenized with 80 L of 40% w / w aqueous sodium hydroxide solution and then mixed with 70 L of 3% w / w aqueous glutaraldehyde solution.

The machine was then started and sprayed on 10 liters of hectare with 250 liters of gelling mixture in about 30 minutes. This corresponded to 5 kg / g / ha of dry matter.

The effects on MV average yield of winter wheat 15 are shown in Table I.

Example 2

Into the container of the apparatus described in Example 1, 3.0 m ^{3 of a} 5 wt% aqueous solution of polyvinyl alcohol (degree of hydrolysis: 88%, average molecular weight: 200,000) was added, and 300 kg of urea, 300 l of aqueous 25 paraffin oil emulsion were added. Chinoin Tannol) and finally 400 liters of 10% w / w aqueous borax solutions

The machine was then started and sprayed with 200 liters per hectare of gelling material in about 30 to 50 minutes.

The effect on the average yield of MV-4 winter wheat is shown in Table I.

Example 3

An experimental winter wheat parcel (MV-4 variety) was sprayed with 3 kg / ha paraffin oil emulsion. Subsequently, an acrylex P-300 gel powder (manufactured by Reanal Fine Glass Factory) was applied to the plot using a dusting device. The gel powder had a particle size of 0.02-0.04 mm; this gel powder can absorb about 45 to 30 times its own weight of water.

The effect on the average yield of MV-4 winter wheat is shown in Table I- 50

Example 4

In each case, as in Example 2, 55 were used, but 200 liters of water were used instead of 300 liters of aqueous paraffin oil emulsion.

The effect on the average yield of MV-4 winter wheat is shown in Table 1. It should be noted that the treatment was carried out in each case in 1986, on plants of advanced stage of the stomach.

Table I

The number of the example Average yield, kg / ha control Handled Difference% First 4.0 4.4 10 Second 3.7 4.6 24.3. Third 3.9 4.7 20.5 4th 3.7 4.4 18.9

PATENT CLAIMS

Claims (4)

1. A method of increasing crop yields by improving water uptake, characterized in that the above-ground portion of the plants is 0.5 to 20 kg / hectare of dry matter per application one or more times during the life cycle after development of 40% of the green weight, preferably until the end of the flowering period. applying an amount of reversible water uptake and release hydrogel in the form of a dry powder or water-containing hydrogel, and optionally, prior to applying the dry powder or water-containing hydrogel, 1 to 10 kg / ha of 18-36 CK liquid non-oxidizing hydrocarbon oil; We also apply aliphatic alcohol containing 20 carbon atoms to the above-ground parts of the plants. 2. A process according to claim 1, wherein the treatment is carried out in an amount of 1 to 10 kg / ha of dry matter. The process according to claim 1 or 2, wherein the treatment comprises a gel having a swelling capacity of 20-100 times. A process according to any one of the preceding claims, characterized in that paraffin oil is applied to the area to be treated prior to applying the dry powder or during application of the water-containing hydrogel. Published by the National Office of Inventions, Budapest R 4938 Responsible for publishing: Zoltán Himer Head of Department