NL2013020B1 - Method for preventing or inhibiting damages to plants during cultivation or for preventing growth retardation. - Google Patents

Abstract

The present invention relates to methods for preventing or inhibiting damages to plants during cultivation or for preventing growth retardation and to method for pest control in plants, especially methods for preventing, or inhibiting, damages caused by insects to plants. The method comprises the step of contacting said plants and/or a growth substrate for said plants with an aqueous suspension, or mixture, comprising amorphous silica or organic siliceous sedimentary rock; wherein said contacting is performed one or more times during the first 50% of the life cycle of said plants and said contacting is not performed during the second 50% of the life cycle of said plants. The present invention relates especially to the application of said methods on chrysanthemum, gerbera, strawberry, peony, lisianthus, orchid, phalenopsis, rose, carnation, lily, iris, freesia, impatiens, spathiphyllum, ranunculus and geranium.

Description

METHOD FOR PREVENTING OR INHIBITING DAMAGES TO PLANTS DURING CULTIVATION OR FOR PREVENTING GROWTH RETARDATION

Description

The present invention relates to methods for preventing or inhibiting damages to plants during cultivation or for preventing growth retardation and to method for pest control in plants, especially methods for preventing, or inhibiting, damages caused by insects to plants. The methods according to the present invention provide environmental friendly pest control means. The present invention further relates to suspension for use in the present pest control methods.

Pest control refers to regulation, or management, of undesired, or harmful, species such as insects or microorganisms. Pest control is at least as old as agriculture, as there has always been a need to keep crops free from pests. Techniques such as crop rotation, companion planting (also known as intercropping or mixed cropping), and the selective breeding of pest-resistant cultivars have a long history.

The use of chemical pesticides date back 4,500 years, when the Sumerians used sulfur compounds as insecticides. The Rig Veda, which is about 4,000 years old, also mentions the use of poisonous plants for pest control. It was only with the industrialization and mechanization of agriculture in the 18 th and 19th century, and the introduction of the insecticides pyre thrum and derris that chemical pest control became widespread. In the 20th century, the discovery of several synthetic insecticides, such as DDT, and herbicides boosted this development. Chemical pest control is still the predominant type of pest control today, although its long-term effects led to a renewed interest in traditional and biological pest control towards the end of the 20th century.

Biological pest control is the control of pests through the control and management of natural predators and parasites. For example: mosquitoes are often controlled by putting Bacillus thuringiensis ssp. israelensis, a bacterium that infects and kills mosquito larvae, in local water sources. The point of biological pest control, or any natural pest control, is to eliminate a pest with minimal harm to the ecological balance of the environment.

Mechanical pest control is the use of hands-on techniques as well as simple equipment, devices, and natural ingredients that provide a protective barrier between plants and insects. For example: weeds can be controlled by being physically removed from the ground. This is referred to as tillage and is one of the oldest methods of weed control.

It is an object of the present invention, amongst other objects, to provide new methods for pest control and especially to provide new methods for pest control with minimal harm to the environment.

This object of the present invention, amongst other objects, is met, according to a first aspect of the present invention, by methods as outlined in the appended claims.

Specifically, this object of the present invention, amongst other objects, is met, according to a first aspect of the present invention, by methods for preventing or inhibiting damages to plants during cultivation, the present methods comprise the step of: a) contacting the present plants and/or a growth substrate for the present plants, preferably the present plants, with an aqueous suspension, or mixture, comprising amorphous silica or organic siliceous sedimentary rock, preferably organic siliceous sedimentary rock; wherein said contacting is performed one or more times during the first 50% of the life cycle of the present plants and the present contacting is not performed during the second 50% of the life cycle of said plants.

According to the present invention, the present damages to plants to be inhibited, or prevented, are preferably damages caused by insect past and/or pathogenic microorganisms, preferably insect pests.

The present inventors have surprisingly discovered that by using the present methods, the pest load on developing, cultivated, or growing, plants can be kept sufficiently low to allow a very efficient biological pest control in the latter stages of development, cultivation or growth. Accordingly, the present method is advantageously combined with any other known method or methods for biological pest control.

Within the context of the present invention, the life cycle of a plant is defined as the timespan between the moment a plant is seeded, planted, or grafted for cultivation and the moment a plant is harvested. Generally, the present life cycle of a plant is between 2 weeks to 26 weeks such as 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22 or 24 weeks. Within the present context, 50% of the first life cycle of a plant means 1 week to 13 weeks from the moment a plant is seeded, planted, or grafted for cultivation such as 2, 3,4, 5, 6, ,7, 8, 9, 10,11, 12 weeks.

According to the present invention, it is essential not to use the present method in the second 50% of the life cycle of plant development, growth or cultivation considering the detrimental effects, such as water absorption and light blocking properties, of the present organic siliceous sedimentary rock or amorphous silica comprising mixtures or aqueous suspension on plants at a later point in the life cycle.

According to the present invention, the present aqueous suspension preferably only consists of water and organic siliceous sedimentary rock such as diatomaceous earth and the present mixture preferably only consists of a mixture of air and organic siliceous sedimentary rock such as diatomaceous earth.

According to a preferred embodiment of the present invention, the present contacting is provided by spraying, dripping or nebulizing, the present plants with a suspension, or mixture, comprising said organic siliceous sedimentary rock or said amorphous silica. The present organic siliceous sedimentary rock preferably is in the form of a fine powder. These powders are readily available in the art.

According to an especially preferred embodiment of the present invention, the present organic siliceous sedimentary rock is diatomaceous earth, preferably in the form of a powder or granulate.

Diatomaceous earth, also known as D.E., diatomite, or kieselgur/kieselguhr, is a naturally occurring, soft, organic siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder. It has a particle size ranging from less than 3 micrometers to more than 1 millimeter, but typically 10 to 200 micrometers. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 60 to 98% silica, with 2 to 4% alumina (attributed mostly to clay minerals) and 0.5 to 2% iron oxide.

Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. It is used as a filtration aid, mild abrasive in products including toothpaste, mechanical insecticide, absorbent for liquids, matting agent for coatings, reinforcing filler in plastics and rubber, anti-block in plastic films, porous support for chemical catalysts, cat litter, activator in blood clotting studies, a stabilizing component of dynamite, and a thermal insulator.

According to another especially preferred embodiment of the present invention, the present method is used for providing ornamental plants with protection for insect pests. The absence of the present pest control agent on plants when harvested provides an additional advantage of the present method for these types of plants.

According to yet another especially preferred embodiment of the present invention, the present method is used for providing protection for plants selected from the group consisting of chrysant, gerbera, strawberry, peony, lisianthus, orchid, phalenopsis, rose, carnation, lily, iris, freesia, impatiens, spathiphyllum, ranunculus and geranium.

The method according to the present invention preferably comprises, before step a, the following steps: providing a powder of diatomaceous earth; providing water spraying, dripping or nebulizing means; wherein said powder of diatomaceous earth is added to said water spraying, dripping or nebulizing means in a water flow through said water spraying, dripping or nebulizing means thereby providing an aqueous suspension, said aqueous suspension is subsequently used for contacting said plants or growth substrate by spraying, dripping or nebulizing.

The present water spraying, dripping or nebulizing means can be a mechanical sprayer comprising a water tank, a pump, a lance (for single nozzles) or boom, and a nozzle (or multiple nozzles) and further means for separately adding diatomaceous earth. The sprayers converts the suspension into droplets which can be large rain-type drops, for example suitable for dripping or tiny almost-invisible particles, for example suitable for nebulizing. This conversion is accomplished by forcing the spray mixture through a spray nozzle under pressure. The size of droplets can be altered through the use of different nozzle sizes, or by altering the pressure under which it is forced, or a combination of both. Large droplets have the advantage of being less susceptible to spray drift, but require more water per unit of area covered. Due to static electricity, small droplets are able to maximize contact with a target surface such as a leaf.

According to the present invention, the present diatomaceous earth is added to the water flow as close to the nozzle as possible to prevent sedimentation of the suspension.

The method according to the present invention can also preferably comprise, before step a, the following steps: providing a powder of diatomaceous earth; providing air spraying means; wherein said powder of diatomaceous earth is added to said air spraying means in an air flow through said air spraying means thereby providing a mixture, said mixture is subsequently used for contacting said plants or growth substrate by spraying.

The methods as described above are especially suitable to be used in enclosed and controlled environments such as a green house and are especially suitable for pest control of flies, trips, aphids or lice.

Considering the beneficial properties of the use of a suspension of diatomaceous earth, the present invention, according to a second aspect, relates to a suspension consisting of water and 10 to 50 wt.% such as 15, 20, 25, 30, 35, 40, 45wt%. Wt% as used herein is as a percentage weight of the total composition. The use of only a combination of water and diatomaceous earth provides environmental advantages over other diatomaceous earth comprising chemical agents to prevent sedimentation of the diatomaceous earth.

According to an especially preferred embodiment, the present growth substrate is bark and, preferably the present plants are orchids.

CLAUSES 1. Method for preventing or inhibiting damages to plants during cultivation or for preventing growth retardation, said method comprises the step of: a) contacting said plants and/or a growth substrate for said plants with an aqueous suspension, or mixture, comprising amorphous silica or organic siliceous sedimentary rock; wherein said contacting is performed one or more times during the first 50% of the life cycle of said plants and said contacting is not performed during the second 50% of the life cycle of said plants. 2. Method according to claim 1, wherein said damages are caused by insect pests and/or pathogenic microorganisms, preferably insect pests. 3. Method according to claim 1 or claim 2, wherein said contacting is provided by spraying, dripping, or nebulizing said plants and/or growth substrate with an aqueous suspension or mixture comprising said amorphous silica and/or said organic siliceous sedimentary rock. 4. Method according to any of the claims 1 to 3, wherein said organic siliceous sedimentary rock is diatomaceous earth. 5. Method according to any of the claims 1 to 4, wherein said diatomaceous earth is in the form of a granulate or powder. 6. Method according to any of the claim 1 to 5, wherein said plant is an ornamental plant. 7. Method according to any of the claims 1 to 5, wherein said plant is selected from the group consisting of chrysanthemum, gerbera, strawberry, peony, lisianthus, orchid, phalenopsis, rose, carnation, lily, iris, freesia, impatiens, spathiphyllum, ranunculus and geranium. 8. Method according to any of the claims 1 to 7, wherein said method comprises the steps, before step a, of: providing a powder of diatomaceous earth; providing water spraying, dripping or nebulizing means; wherein said powder of diatomaceous earth is added to said water spraying, dripping or nebulizing means in a water flow through said water spraying, dripping or nebulizing means thereby providing an aqueous suspension, said aqueous suspension is subsequently used for contacting said plants by spraying, dripping or nebulizing. 9. Method according to claim 8, wherein said aqueous suspension is provided by mixing said powder of diatomaceous earth with said water flow. 10. Method according to any of the claims 1 to 7, wherein said method comprises the steps, before step a, of: providing a powder of diatomaceous earth; providing air spraying means; wherein said powder of diatomaceous earth is added to said air spraying means in an air flow through said air spraying means thereby providing a mixture, said mixture is subsequently used for contacting said plants by spraying. 11. Method according to any of the claims 1 to 10, wherein said method is used on plants grown or cultivated in a green house. 12. Method according to any of the claims 1 to 11, wherein said insects are flies, trips, aphids, ants, slugs or lice. 13. Suspension consisting of water and 0.00003333333 to 65 wt.% diatomaceous earth. 14. Method according to any of the claims 1 to 12, wherein said growth substrate comprises bark and said plant is preferably orchid.

Claims (14)

A method for preventing or inhibiting damage to plants or preventing growth retardation during cultivation, the method comprising the step of: a) contacting said plants and / or a growth substrate for said plants with an aqueous suspension, or a mixture comprising amorphous silica or a sedimentary rock comprising organic silica; wherein said contacting is performed one or more times during the first 50% of the life cycle of said plants and said contacting is not performed during the second 50% of the life cycle of said plants. Method according to claim 1, wherein said damage is caused by harmful insects and / or microorganisms, preferably harmful insects. A method according to claim 1 or claim 2, wherein said contacting is provided by spraying, dripping or spraying said plants and / or said growth substrate with said aqueous suspension or said mixture comprising amorphous silica or a sedimentary rock comprising organic silica. The method of any one of claims 1 to 3, wherein said sedimentary rock comprising organic silica is diatomaceous earth. The method of any one of claims 1 to 4, wherein said diatomaceous earth is in the form of a powder or granulate. The method according to any of claims 1 to 5, wherein said plants are ornamental plants. The method according to any of claims 1 to 5, wherein said plants are selected from the group consisting of chrysanthemum, gerbera, strawberry, peony, lisianthus, orchid, phalenopsis, rose, carnation, lily, iris, freesia, impatiens, spathiphyllum, ranunculus and geranium. The method of any one of claims 1 to 7, wherein said method comprises, for step a, the steps of: providing a powder or granulate of diatomaceous earth; providing water spraying, sprinkling or spraying agents; wherein said powder or granulate of diatomaceous earth is added to said spraying, dripping or nebulizing agents in a water stream through said spraying, dripping or nebulizing agents thereby providing an aqueous suspension, said aqueous suspension is then used for contacting contacting said plants and / or said growth substrate by spraying, dripping or spraying. The method of claim 8, wherein said suspension is provided by mixing the diatomaceous earth with said water stream. The method of any one of claims 1 to 7, wherein said method comprises, for step a, the steps of: providing a powder or granulate of diatomaceous earth; providing air spraying agents; wherein said powder or granulate of diatomaceous earth is added to said air spraying means in an air stream through said air spraying means and thereby providing a mixture, said mixture is then used for contacting said plants by spraying. A method according to any of claims 1 to 10, wherein said method is used on plants that are grown, grown or cultivated in a greenhouse. The method of any one of claims 1 to 11, wherein said insects are flies, thrips, aphids, snails, ants or lice. 13. Suspension composed of water and: 0.00003333333 up to and including 65% by weight of diatomaceous earth. A method according to any of claims 1 to 12, wherein said growth substrate comprises bark and said plant is preferably an orchid.