SE1350743A1

SE1350743A1 - A process for treating a plant with a solution comprising a nanofibrillated polysaccharide

Info

Publication number: SE1350743A1
Application number: SE1350743A
Authority: SE
Inventors: Martin Häggblom; Isto Heiskanen; Veikko Jokela
Original assignee: Stora Enso Oyj
Priority date: 2013-06-18
Filing date: 2013-06-18
Publication date: 2014-12-19
Also published as: WO2014203121A1

Abstract

12 Abstract The present invention relates to a method for treating a plant or afungus which method comprises the steps of; (i) providing a solutioncomprising water, (ii) adding a nanofibrillated polysaccharide to the solutionthereby forming a suspension wherein the concentration of nanofibrillatedpolysaccharide in the suspension is above 1,5% by weight and (iii) subjectingthe plant or fungus to said suspension in order to provide the plant or funguswith water.

Description

METHOD FOR TREATING A PLANT WITH A SOLUTIONCOMPRISING A NANOFIBRILLATED POLYSACCHARIDE Field of the invention The present invention relates to a method for treatment of a plant or afungus with a solution comprising water and a nanofibrillated polysaccharide.

Background ln horticulture and agriculture there is an ongoing struggle to find ways to reduce the amount of water needed by the plants. Especially in areasprone to drought there is an obvious problem with limited amount of wateravailable. Furthermore, the water tend to evaporated from the plants and/orthe ground which both increases the amount of water needed as well asincreases the amounts of salts and other components that will accumulateinto the ground.

The most common way to solve the problem with limited water accesstoday is by controllable watering systems, such as drip irrigation.

Another was to solve the problem is by using water absorbingadditives. The water absorbing additive absorbs excess water and releases itthrough osmosis to the roots of the plants. The most common used waterabsorbing additives are water absorbing polymers, such as polyacrylamideswhich also are called water crystals. The drawbacks with water absorbingpolymers are high cost, low biodegradability, toxicity and that it might bedifficult to apply the water absorbing polymers evenly to the plants.

Furthermore, in horticulture and agriculture there is also a need todecrease the amount to fertilizers used. Due to demands of high wateramounts, i.e. high water flows to the plants, especially in areas with warm orhot climates, a large part of the added fertilizers end up in the waste waters flows that flows away from the plants and are thus not absorbed by the plants.

Consequently, larger amounts of fertilizers need to be added in order for theplants to be able to absorb the fertilizers.

There is thus a need for an improved method for treating plants inorder to reduce the amount of water and fertilizers needed in horticulture andagriculture.

Summary of the invention The main objects of the present invention are to provide an improvedmethod for providing plants or fungi with water.

These objects and other advantages are achieved by the methodaccording to c|aim 1. The present invention relates to a method for treating aplant or a fungus which method comprises the steps of; (i) providing asolution comprising water, (ii) adding a nanofibrillated polysaccharide to thesolution thereby forming a suspension wherein the concentration ofnanofibrillated polysaccharide in the suspension is above 1,5% by weight and(iii) subjecting the plant or fungus to said suspension in order to provide theplant or fungus with water. By treating a plant or a fungus with a suspensioncomprising a nanofibrillated polysaccharide it has been shown that the waterconsumption of the plant or fungus is reduced. lt may be preferred that the nanofibrillated polysaccharide ismicrofibrillated cellulose. lt has been shown that microfibrillated cellulose hasexcellent water binding properties as well as excellent water releasingproperties. Furthermore, microfibrillated cellulose is biodegradable whichmakes it a very environmental friendly material to use. lt is preferred that the concentration of the nanofibrillated polysaccharide in the suspension is between 1,5-30% by weight, preferablybetween 3-10 % by weight. Concentrations below 1,5% by weight did notseem to give the advantage with optimal water releasing properties of thesuspension. Furthermore, concentrations above 30% by weight seem to beless beneficial since the suspension almost is in solid state and the waterrelease is very limited.

The suspension may be in form of a gel. lt may be beneficial to subjectthe plant or fungus to a gel formed suspension since a gel may be easier todistribute to the plant or fungus and the water loss, i.e. water being flownaway from the plant or fungus is strongly reduced. lt may be preferred to pour the suspension onto the plant or fungus. lnthis way it is possible to subject the plant or fungus to the suspension in avery easy way.

Furthermore, it may be preferred that the suspension is in solid form,preferably in the form of a sheet, composite material, foam or a powder whenthe plant or fungus is subjected to the suspension. Water is preferablythereafter added in order for the plant or fungus to be able to absorb anywater from the suspension. Once water is added to the solid suspension, thenanofibrillated polysaccharide of the suspension is redispersed and absorbsthe water which makes it possible for the plant or fungus to absorb the waterof the suspension.

A benefit with the present invention is that it is also possible to adddifferent additives to the solution and/or to the suspension and due to thecharacteristic of the suspension, the additive will mostly be retained in thesuspension until the plant or fungus can absorb it. Consequently, smalleramounts of additives are removed by waste water etc. lt may be preferred to add a nutrition agent to the solution and/or to thesuspension. ln this way the plant or fungus is also subjected to nutritionagents at the same time as it absorbs the water. lt is also possible to add a pesticide or biocide to the solution and/or tothe suspension. ln this way the plant or fungus is also subjected to pesticideor biocide at the same time as it absorbs the water. lt is thus possible to alsoprotect the plant or fungus from e.g. microbial and/or unwanted fungusgrowth.

For some applications it may be beneficial to add growth hormones tothe solution and/or to the suspension. The growth hormones will thus beabsorbed by the plant or fungus once it absorbs the water of the suspension. lt may be preferred that the plant is a cut flower. By subjecting a cutflower, such as a tulip or rose, to suspension it has been shown that thelifetime of the cut flowers are strongly improved at the same time as theamount of water needed is reduced. lt may be preferred that the plant is a plant planted in soil, such as atree, a bush or crops. By subjecting the roots of a plant planted in soil to thesuspension the amount of water need by the plant is reduced.

Detailed description Definition of nanofibrillated polvsaccharide This definition includes bacterial cellulose or nanocellulose spun witheither traditional spinning techniques or with electrostatic spinning. ln thesecases, the material is preferably a polysaccharide but not limited to solely apolysaccharide. A polysaccharide can be e.g. starch, protein, cellulosederivatives etc.

Also microfibrillated cellulose as defined more in detail below isincluded in this definition.

Definition of microfibrillated cellulose The microfibrillated cellulose (MFC) is also known as nanocellulose. ltis a material typically made from wood cellulose fibers, from both hardwood orsoftwood fibers. lt can also be made from microbial sources, e.g. seaweedfermented fibers, agricultural fibers such as wheat straw pulp, bamboo orother non-wood fiber sources. ln microfibrillated cellulose the individualmicrofibrils have been partly or totally detached from each other. Amicrofibrillated cellulose fibril is normally very thin (e.g. a width of 5-200 nm)and the length is often between 100 nm to 10 um. However, the microfibrilsmay also be longer, for example between 10-200 um, even lengths of 2000um can be found due to wide length distribution.

Fibers that have been fibrillated and which have microfibrils on thesurface and microfibrils that are separated and located in a water phase of aslurry are included in the definition of MFC.

Furthermore, cellulose whiskers, microcrystalline cellulose (MCC),microcellulose (MC), nanocrystalline cellulose (NCC), nanofibrillated cellulose(NFC) or regenerated cellulose fibers and particles are also included in thedefinition of MFC.

The fibrils may also be polymer coated fibrils, i.e. a modified fibril eitherchemically or physically, being thus either hydrophilic or hydrophobic.

Microfibrillated cellulose (MFC) can be produced in a number ofdifferent ways. lt is possible to mechanically treat cellulosic fibers formingmicrofibrils. The production of nanoce||u|ose or microfibrillated cellulose withbacteria, or fermentation, is another option. lt is also possible to producemicrofibrils from cellulose by the aid of different chemicals and/or enzymeswhich will break the interfibrillar bonds, or even dissolve the fibers and fibrills.One example of production of microfibrillated cellulose (MFC) is shown inWO2007091942 which describes production of MFC by the aid of refining incombination with addition of an enzyme.

Definition of plantThe definition of plant includes all kind of plants with the traits of being multicellular, possessing cellulose, and having the ability to carry outphotosynthesis. The definition includes all kind of plants that could be used inhorticulture or agriculture. Example of plants are cut flowers, trees, bushes,plant cells, grains, crops etc.

Definition of fungusA fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the morefamiliar mushrooms. These organisms are classified as a kingdom, Fungi,which is separate from plants, animals, and bacteria.

The present invention relates to an improved method for subjectingplants or fungi to water, eventual nutrients or other additives. The plant orfungus is subjected to a suspension that comprises a nanofibrillatedpolysaccharides in an amount of at least 1,5% by weight (of the total weight ofthe suspension). lt has been shown that by subjecting a plant or a fungus tothe suspension comprising a nanofibrillated polysaccharide, such asmicrofibrillated cellulose, the needed amount of water can be reduced.

Due to that microfibrillated cellulose has high amounts of fixed -OHgroups at the surface of the fibrils, the MFC has a great absorption capabilityof polar solvents, e.g. water. Due to this property, the MFC can be used as a carrier and/or distributor of Iiquids, for example to plants. Furthermore, MFChas a very high water binding capacity which reduces the evaporation rate ofwater and decreased evaporation of water which strongly reduces the amountof water that needs to be added to plants in horticulture and/or agricuiture.

Furthermore, MFC has the property to form solid remaining materialsat low solid concentrations. Due to this property, a continuous hydrostaticpressure is formed within the plant or fungus when the plant or fungusabsorbs water from the suspension, compared to if the plant or fungus wouldabsorb liquid water. This continuous hydrostatic pressure will ensure an evenbut yet restricted water flow to the plant or fungus. A restricted water flowfrom the suspension also closes the pores/epistles of the plant surface sincethe plant “believes” it is going into a dry season. ln this way the plantdecreases the water evaporation from its surface and the water consumptiondecreases without significantly affecting the growing rate of the plant. lt is preferred that the concentration of the nanofibrillatedpolysaccharide in the suspension is between 1,5-30% by weight, preferablybetween 3-10 % by weight of the total weigh of the suspension.Concentrations below 1,5% by weight did not seem to give the advantagewith the even but yet restricted water flow from the suspension to the plant orfungus, i.e. no continuous hydrostatic pressure was formed. Furthermore,concentrations above 30% by weight seem to be less beneficial since thesuspension will be in almost solid state and the water release is very limited. lt may be preferred to pour the suspension onto the plant or fungus. lnthis way it is possible to subject the plant or fungus to the suspension in avery easy way. However, it may also be possible to add the suspension to theplant or fungus in any possible way.

The suspension may be in form of a gel. lt may be beneficial to subjectthe plant or fungus to a gel formed suspension since a gel may be easier todistribute to the plant or fungus and the water loss, i.e. water being flownaway from the plant or fungus is strongly reduced.

Furthermore, it may be preferred that the suspension is in solid form,preferably in the form of a sheet, composite material, foam or a powder when the plant or fungus is subjected to the suspension. By adding the suspensionin solid form it is very easy to distribute and transport, since the amount ofwater being transported in limited. Once water is added to the solidsuspension, the nanofibrillated polysaccharide of the suspension isredispersed and absorbs the water which makes it possible for the plant orfungus to absorb the water of the suspension. Normally the suspension is insolid form when it has a concentration of between 30-100% by weight.However, it is possible to increase the concentration of the suspension to100% by weight, i.e. the suspension will thus comprise no water or liquid. Thismay be beneficial when the suspension should be transported to the sitewhere the plants or fungi to be treated are located. However, it is of coursenot possible to provide a plant or a fungus with water if the suspension doesnot comprise any. Consequently, water must be added to the suspensioneither before the plant or fungus is subjected to the suspension or after.Water can either be added by drop irrigation or other water adding methods. ltis also possible that water is added by rainfall. Once water is added, thenanofibrillated polysaccharide of the suspension will absorb the water or liquidand thereafter provide the plant or fungus with the water. The amount ofwater that needs to be added is decided by the dry content or concentrationof the suspension. lt is however important that the concentration of thesuspension is above 1,5% by weight in order to get the desired results.

Another benefit with the present invention is that it is also possible tosubject the plant or fungus to different additives at the same time as the plantor fungus is provided with water. Additives may be added to the solutionand/or to the suspension. Due to the characteristic of the suspension, theadditive will mostly be retained in the suspension until the plant or fungus canabsorb it. Consequently, smaller amounts of additives are removed from theplant or fungus by for example waste water flows etc. By the presentinvention it is thus possible to reduce the amount of needed nutrition agents,e.g. fertilizers, since the fertilizers or other additives will be retained in thesuspension until it is absorbed by the plant or fungus. lt is also possible toreuse unused additives after harvesting of the plant or fungus, since theadditive still are retained in the suspension. Possible additives are nutritionagents, such as fertilizers and minerals, pesticides or biocides, or growthhormones. Examples of nutrition agents are fertilizers and minerals, e.g.macronutrients such as sodium, phosphorus, potassium, calcium, magnesium and sulfur and micronutrients such as iron, chloride, manganese,molybdenum, zinc, copper and boron. lt may be preferred that the plant is a cut flower. By pouring thesuspension to the cut flower, for example in the vase in which the cut flowersare standing, it has been shown that the lifetime ofthe cut flowers arestrongly improved at the same time as the amount of water needed isreduced. lt may be preferred that the plant is a plant planted in soil, such as atree, a bush or crops. By subjecting the roots of a plant planted in soil to thesuspension the amount of water need by the plant is reduced.

ExamgleTulips of Rainbow brand were used. The stems of the tulips were cut approximately 2 cm from the bottom at a 45° angle.

Microfibrillated cellulose produced from sulphate pulp was used as awater carrier material in the samples below. The microfibrillated cellulose wasadded to a water solution in order to form a suspension with differentconcentrations as mentioned below.

Three test samples were set-up: 1. Reference sample with tulips in tap water 2. Tulips in MFC suspension with a concentration of 1,1 % by weight3. Tulips in MFC suspension with a concentration of 3,2% by weight To sample 1 tap water was added and to sample 2 and 3 a suspensionwith the mentioned concentrations of MFC was added to a vase in which thetulips were placed (6 tulips in each vase).

To each vase 22,5 ml of either water (to sample 1) or respectivesuspension (to sample 2 and 3) was added.

After approximately 4 hours almost all water in sample 1 had vanishedso an additional 30 ml of respectively liquids were added to respective vase.

After 14 hour, all of the tap water in sample 1 had vanished so anadditional 30 ml water was added to sample 1 (note that no additional liquidswere added to sample 2 or 3). Consequently, in total 85,5ml of water wasadded to sample 1, 52,5 ml of suspension with a concentration of 1,1% wasadded to sample 2 and 52,5 ml of suspension with a concentration of 3,2%was added to sample 3.

After 36 hour almost every tulip in sample 1 had wither and the tulips in sample 2 had begun to droop. However, the tulips in sample 3 were still fresh.

After 50 hours the tulips in sample 3 started to droop and the testended.

Consequently, the tulips subjected to the suspension with aconcentration of 3,2% by weight lasted approximately 24 hours longercompared to the tulips in tap water despite that 35% less water was added,i.e. despite less water consumption. The tulips in sample 3 lasted andapproximately 14 hours longer compared to the tulips subjected to thesuspension with a concentration of 1,1% by weight (sample 2).

By subjecting a plant, in this example tulips, to a suspension with aconcentration of 3,2% by weight of microfibrillated cellulose it was possible tostrongly increase the life of the plant. ln view of the above detailed description of the present invention, othermodifications and variations will become apparent to those skilled in the art.However, it should be apparent that such other modifications and variationsmay be effected without departing from the spirit and scope of the invention.

Claims

Method for treating a plant or a fungus which method comprises the steps of: - (i) providing a solution comprising water, - (ii) adding a nanofibrillated polysaccharide to the solution therebyforming a suspension wherein the concentration of nanofibrillatedpolysaccharide in the suspension is above 1,5% by weight and - (iii) subjecting the plant or fungus to said suspension in order toprovide the plant or fungus with water.
The method according to claim 1 wherein the nanofibrillatedpolysaccharide is microfibrillated cellulose.
The method according to any of the preceding claims wherein theconcentration of nanofibrillated polysaccharide in the suspension isbetween 1,5-30%-by weight, preferably between 3-10 % by weight.
The method according to any of the preceding claims wherein thesuspension is in form of a gel.
The method according to any of the preceding claims wherein the plantor fungus is subjected to the suspension by pouring the suspensiononto the plant or fungus.
The method according to any of claims 1-3 wherein the suspension isin solid form, preferably in the form of a sheet, composite material,foam or a powder.
The method according to any of the preceding claims wherein the step(iii) further comprises addition of water to the suspension after the plantor fungus has been subjected to said suspension.
The method according to any of the preceding claims wherein anutrition agent is added to the solution and/or to the suspension.
The method according to any of the preceding claims wherein apesticide or biocide is added to the solution and/or to the suspension.
10.
11.
12. 11 The method according to any of the preceding claims wherein growthhormones are added to the solution and/or to the suspension. The method according to any of the preceding claims wherein the plantis a cut flower. The method according to any of the preceding claims wherein the plantis a plant, such as a tree or bush, planted in soil.