Field of the invention

The present invention relates to a method for treatment of a plant or a fungus with a solution comprising water and a nanofibrillated polysaccharide. Background

In horticulture and agriculture there is an ongoing struggle to find ways to reduce the amount of water needed by the plants. Especially in areas prone to drought there is an obvious problem with limited amount of water available. Furthermore, the water tend to evaporated from the plants and/or the ground which both increases the amount of water needed as well as increases the amounts of salts and other components that will accumulate into the ground.

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

Another was to solve the problem is by using water absorbing additives. The water absorbing additive absorbs excess water and releases it through osmosis to the roots of the plants. The most common used water absorbing additives are water absorbing polymers, such as polyacrylamides which also are called water crystals. The drawbacks with water absorbing polymers are high cost, low biodegradability, toxicity and that it might be difficult to apply the water absorbing polymers evenly to the plants. Furthermore, in horticulture and agriculture there is also a need to decrease the amount to fertilizers used. Due to demands of high water amounts, i.e. high water flows to the plants, especially in areas with warm or hot 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 the plants to be able to absorb the fertilizers. There is thus a need for an improved method for treating plants in order to reduce the amount of water and fertilizers needed in horticulture and agriculture. Summary of the invention

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

These objects and other advantages are achieved by the method according to claim 1 . The present invention relates to a 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 thereby forming a suspension wherein the concentration of nanofibrillated polysaccharide in the suspension is above 1 ,5% by weight and (iii) subjecting the plant or fungus to said suspension in order to provide the plant or fungus with water. By treating a plant or a fungus with a suspension comprising a nanofibrillated polysaccharide it has been shown that the water consumption of the plant or fungus is reduced. It may be preferred that the nanofibrillated polysaccharide is

microfibril I ated cellulose. It has been shown that microfibrillated cellulose has excellent water binding properties as well as excellent water releasing properties. Furthermore, microfibrillated cellulose is biodegradable which makes it a very environmental friendly material to use.

It is preferred that the concentration of the nanofibrillated

polysaccharide in the suspension is between 1 ,5-30% by weight, preferably between 3-10 % by weight. Concentrations below 1 ,5% by weight did not seem to give the advantage with optimal water releasing properties of the suspension. Furthermore, concentrations above 30% by weight seem to be less beneficial since the suspension almost is in solid state and the water release is very limited.

The suspension may be in form of a gel. It may be beneficial to subject the plant or fungus to a gel formed suspension since a gel may be easier to distribute to the plant or fungus and the water loss, i.e. water being flown away from the plant or fungus is strongly reduced. It may be preferred to pour the suspension onto the plant or fungus. In this way it is possible to subject the plant or fungus to the suspension in a very 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 when the plant or fungus is subjected to the suspension. Water is preferably thereafter added in order for the plant or fungus to be able to absorb any water from the suspension. Once water is added to the solid suspension, the nanofibrillated polysaccharide of the suspension is redispersed and absorbs the water which makes it possible for the plant or fungus to absorb the water of the suspension.

A benefit with the present invention is that it is also possible to add different additives to the solution and/or to the suspension and due to the characteristic of the suspension, the additive will mostly be retained in the suspension until the plant or fungus can absorb it. Consequently, smaller amounts of additives are removed by waste water etc.

It may be preferred to add a nutrition agent to the solution and/or to the suspension. In this way the plant or fungus is also subjected to nutrition agents at the same time as it absorbs the water.

It is also possible to add a pesticide or biocide to the solution and/or to the suspension. In this way the plant or fungus is also subjected to pesticide or biocide at the same time as it absorbs the water. It is thus possible to also protect the plant or fungus from e.g. microbial and/or unwanted fungus growth.

For some applications it may be beneficial to add growth hormones to the solution and/or to the suspension. The growth hormones will thus be absorbed by the plant or fungus once it absorbs the water of the suspension.

It may be preferred that the plant is a cut flower. By subjecting a cut flower, such as a tulip or rose, to suspension it has been shown that the lifetime of the cut flowers are strongly improved at the same time as the amount of water needed is reduced. It may be preferred that the plant is a plant planted in soil, such as a tree, a bush or crops. By subjecting the roots of a plant planted in soil to the suspension the amount of water need by the plant is reduced.

Detailed description

Definition of nanofibrillated polysaccharide

This definition includes bacterial cellulose or nanocellulose spun with either traditional spinning techniques or with electrostatic spinning. In these cases, the material is preferably a polysaccharide but not limited to solely a polysaccharide. A polysaccharide can be e.g. starch, protein, cellulose derivatives etc.

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

Definition of microfibrillated cellulose

The microfibrillated cellulose (MFC) is also known as nanocellulose. It is a material typically made from wood cellulose fibers, from both hardwood or softwood fibers. It can also be made from microbial sources, e.g. seaweed fermented fibers, agricultural fibers such as wheat straw pulp, bamboo or other non-wood fiber sources. In microfibrillated cellulose the individual microfibrils have been partly or totally detached from each other. A

microfibrillated cellulose fibril is normally very thin (e.g. a width of 5-200 nm) and the length is often between 100 nm to 10 pm. However, the microfibrils may also be longer, for example between 10-200 pm, even lengths of 2000 pm can be found due to wide length distribution.

Fibers that have been fibrillated and which have microfibrils on the surface and microfibrils that are separated and located in a water phase of a slurry 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 the definition of MFC. The fibrils may also be polymer coated fibrils, i.e. a modified fibril either chemically or physically, being thus either hydrophilic or hydrophobic.

Microfibrillated cellulose (MFC) can be produced in a number of different ways. It is possible to mechanically treat cellulosic fibers forming microfibrils. The production of nanocellulose or microfibrillated cellulose with bacteria, or fermentation, is another option. It is also possible to produce microfibrils from cellulose by the aid of different chemicals and/or enzymes which will break the interfibrillar bonds, or even dissolve the fibers and fibrills. One example of production of microfibrillated cellulose (MFC) is shown in WO2007091942 which describes production of MFC by the aid of refining in combination with addition of an enzyme.

Definition of plant

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

Definition of fungus

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar 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 subjecting plants or fungi to water, eventual nutrients or other additives. The plant or fungus is subjected to a suspension that comprises a nanofibrillated polysaccharides in an amount of at least 1 ,5% by weight (of the total weight of the suspension). It has been shown that by subjecting a plant or a fungus to the suspension comprising a nanofibrillated polysaccharide, such as microfibrillated cellulose, the needed amount of water can be reduced. Due to that microfibrillated cellulose has high amounts of fixed -OH groups at the surface of the fibrils, the MFC has a great absorption capability of polar solvents, e.g. water. Due to this property, the MFC can be used as a carrier and/or distributor of liquids, for example to plants. Furthermore, MFC has a very high water binding capacity which reduces the evaporation rate of water and decreased evaporation of water which strongly reduces the amount of water that needs to be added to plants in horticulture and/or agriculture.

Furthermore, MFC has the property to form solid remaining materials at low solid concentrations. Due to this property, a continuous hydrostatic pressure is formed within the plant or fungus when the plant or fungus absorbs water from the suspension, compared to if the plant or fungus would absorb liquid water. This continuous hydrostatic pressure will ensure an even but yet restricted water flow to the plant or fungus. A restricted water flow from the suspension also closes the pores/epistles of the plant surface since the plant "believes" it is going into a dry season. In this way the plant decreases the water evaporation from its surface and the water consumption decreases without significantly affecting the growing rate of the plant.

It is preferred that the concentration of the nanofibrillated

polysaccharide in the suspension is between 1 ,5-30% by weight, preferably between 3-10 % by weight of the total weigh of the suspension.

Concentrations below 1 ,5% by weight did not seem to give the advantage with the even but yet restricted water flow from the suspension to the plant or fungus, i.e. no continuous hydrostatic pressure was formed. Furthermore, concentrations above 30% by weight seem to be less beneficial since the suspension will be in almost solid state and the water release is very limited.

It may be preferred to pour the suspension onto the plant or fungus. In this way it is possible to subject the plant or fungus to the suspension in a very easy way. However, it may also be possible to add the suspension to the plant or fungus in any possible way.

The suspension may be in form of a gel. It may be beneficial to subject the plant or fungus to a gel formed suspension since a gel may be easier to distribute to the plant or fungus and the water loss, i.e. water being flown away 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 suspension in solid form it is very easy to distribute and transport, since the amount of water being transported in limited. Once water is added to the solid

suspension, the nanofibrillated polysaccharide of the suspension is

redispersed and absorbs the water which makes it possible for the plant or fungus to absorb the water of the suspension. Normally the suspension is in solid form when it has a concentration of between 30-100% by weight.

However, it is possible to increase the concentration of the suspension to 100% by weight, i.e. the suspension will thus comprise no water or liquid. This may be beneficial when the suspension should be transported to the site where the plants or fungi to be treated are located. However, it is of course not possible to provide a plant or a fungus with water if the suspension does not comprise any. Consequently, water must be added to the suspension either 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. It is also possible that water is added by rainfall. Once water is added, the nanofibrillated polysaccharide of the suspension will absorb the water or liquid and thereafter provide the plant or fungus with the water. The amount of water that needs to be added is decided by the dry content or concentration of the suspension. It is however important that the concentration of the suspension 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 to subject the plant or fungus to different additives at the same time as the plant or fungus is provided with water. Additives may be added to the solution and/or to the suspension. Due to the characteristic of the suspension, the additive will mostly be retained in the suspension until the plant or fungus can absorb it. Consequently, smaller amounts of additives are removed from the plant or fungus by for example waste water flows etc. By the present invention 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 the suspension until it is absorbed by the plant or fungus. It is also possible to reuse unused additives after harvesting of the plant or fungus, since the additive still are retained in the suspension. Possible additives are nutrition agents, such as fertilizers and minerals, pesticides or biocides, or growth hormones. 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.

It may be preferred that the plant is a cut flower. By pouring the suspension to the cut flower, for example in the vase in which the cut flowers are standing, it has been shown that the lifetime of the cut flowers are strongly improved at the same time as the amount of water needed is reduced. It may be preferred that the plant is a plant planted in soil, such as a tree, a bush or crops. By subjecting the roots of a plant planted in soil to the suspension the amount of water need by the plant is reduced.

Example

Tulips 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 a water carrier material in the samples below. The microfibrillated cellulose was added to a water solution in order to form a suspension with different concentrations 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 weight

3. 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 suspension with the mentioned concentrations of MFC was added to a vase in which the tulips were placed (6 tulips in each vase).

To each vase 22,5 ml of either water (to sample 1 ) or respective suspension (to sample 2 and 3) was added. After approximately 4 hours almost all water in sample 1 had vanished so 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 an additional 30 ml water was added to sample 1 (note that no additional liquids were added to sample 2 or 3). Consequently, in total 85,5ml of water was added to sample 1 , 52,5 ml of suspension with a concentration of 1 , 1 % was added 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 test ended.

Consequently, the tulips subjected to the suspension with a

concentration of 3,2% by weight lasted approximately 24 hours longer compared 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 and approximately 14 hours longer compared to the tulips subjected to the suspension with a concentration of 1 , 1 % by weight (sample 2).

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