Pseudomonas fluorescens inhibit annual bluegrass and rough bluegrass root growth and germination

Abstract

A biocontrol agent containing one or more novel and isolated Pseudomonas fluorescens strains (P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), and P. fluorescens biovar A strain LRS12 (NRRL B-50853)) and a biocontrol agent containing one, two or three of these bacteria with an agriculturally acceptable carrier are useful for the control of annual bluegrass and rough bluegrass root growth and germination. The biocontrol agents of this invention may be applied to the soil and/or seeds in the fall with inhibition occurring in subsequent years. The biocontrol agent can also be used in combination with herbicides that can inhibit the growth and seed production of any standing annual bluegrass and/or fertilizer to stimulate growth of the desirable plant that will compete with the annual bluegrass weed and/or rough bluegrass. Methods for use of these biocontrol agents to control to growth of annual bluegrass and rough bluegrass are also provided.

Description

BACKGROUND OF INVENTION[0001]1. Field of Invention[0002]This invention relates to novel isolated Pseudomonas fluorescens strains that have been isolated, selected, and characterized from the naturally occurring soil bacterial populations because they inhibit the growth of annual bluegrass (Poa annua L.) or inhibit the growth of both annual bluegrass (Poa annua L.) and rough bluegrass (Poa trivialis), but do not inhibit the growth of desired grasses, such as turfgrasses, cereal crops, and native plants. This invention also relates to novel compositions that contain the novel Pseudomonas fluorescens strains described herein. In addition this invention relates to methods of using the novel, isolated P. fluorescens strains and the novel compositions, alone or in combination with other P. fluorescens strains, herbicides, and / or fertilizers.[0003]2. Description of the Prior Art[0004]Annual bluegrass (Poa annua L.) is a cool-season annual grass that is a major weed species in turf, turfgra...

AI Technical Summary

Benefits of technology

[0009]It is another object of this invention to have a biocontrol agent that can control and / or inhibit annual bluegrass or can control and / or inhibit both annual bluegrass (Poa annua L.) and rough bluegrass root growth and seed germination and that the biocontrol agent contains P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), P. fluorescens biovar A strain LRS12 (NRRL B-50853), combinations thereof, and compositions containing one or more of these bacteria, P. fluorescens strain LRS12 (NRRL B-50853) controls and / or inhibits root growth and seed germination of both P. annua L. and P. trivialis.

[0010]It is an object of this invention to have a biocontrol agent that can control and / or inhibit annual bluegrass or can control and / or inhibit both annual bluegrass and rough bluegrass root growth and seed germination. The biocontrol agent contains P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), or P. fluorescens biovar A strain LRS12 (NRRL B-50853), or combinations thereof, where P. fluorescens strain LRS12 (NRRL B-50853) controls and / or inhibits root growth and seed germination of both P. annua L. and P. trivialis. The concentration of the bacteria applied to the treated land ranges between approximately 105 to approximately 1011 cfu bacteria per square meter of treated land. For one alternative embodiment, if one single bacterial strain is present in the biocontrol agent, the bacteria's concentration is approximately 108 cfu bacteria per square meter of treated land. For another alternative embodiment, if two or all three strains of bacteria are present in the biocontrol agent, the concentration for each strain of bacteria ranges from approximately 107 to approximately 108 cfu bacteria per square meter of treated land. It is another object of this invention that the biocontrol agent contains a herbicide and / or a fertilizer.

[0011]It is an object of this invention to have a biocontrol agent that can control and / or inhibit annual bluegrass or can control and / or inhibit both annual bluegrass and rough bluegrass root growth and seed germination and that the biocontrol agent contains an agriculturally acceptable carrier and either P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), or P. fluorescens biovar A strain LRS12 (NRRL B-50853), or combinations thereof, where P. fluorescens strain LRS12 (NRRL B-50853) controls and / or inhibits root growth and seed germination of both P. annua L. and P. trivialis. It is further object of this invention that the biocontrol agent can optionally contain a herbicide and / or a fertilizer. It is another object of this invention that the agriculturally acceptable carrier can be a seed from one or more desired plants, rice, talc, one or more carbohydrates, one or more polysaccharides, one or more polymeric porous materials, milk, water, medium, and pellets made from a cereal grain flour or meal. The concentration of the bacteria applied to the treated land ranges between approximately 105 to approximately 1011 cfu bacteria per square meter of treated land. For one alternative embodiment, if one single bacterial strain is present in the biocontrol agent, the bacteria's concentration is approximately 108 cfu bacteria per square meter of treated land. For another alternative embodiment, if two or all three strains of bacteria are present in the biocontrol agent, the concentration for each strain of bacteria ranges from approximately 107 to approximately 108 cfu bacteria per square meter of treated land.

[0012]It is another object of this invention to have a method for controlling the growth of annual bluegrass and / or rough bluegrass in an area in need of treatment by applying a biocontrol agent in an amount effective to control the growth of annual bluegrass and / or rough bluegrass to the area. It is a further object of this invention that the biocontrol agent contains P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), or P. fluorescens biovar A strain LRS12 (NRRL B-50853), or combinations thereof; and optionally a herbicide and / or a fertilizer, where P. fluorescens strain LRS12 (NRRL B-50853) controls the growth of both P. annua L. and P. trivialis. The concentration of the bacteria applied to the treated land ranges between approximately 105 to approximately 1011 cfu bacteria per area in need of treatment. For one alternative embodiment, if one single bacterial strain is present in the biocontrol agent, the bacteria's concentration is approximately 108 cfu bacteria per area in need of treatment. For another alternative embodiment, if two or all three strains of bacteria are present in the biocontrol agent, the concentration for each strain of bacteria ranges from approximately 107 to approximately 108 cfu bacteria per area in need of treatment. It is a further object of this invention that the application of the biocontrol agent occurs when the soil is moist (i.e., after rain or irrigation) or prior to irrigating the area in need of treatment or when rain is anticipated to occur shortly after application of the biocontrol agent. It is another object of this invention that the air temperature in the area in need of treatment should be between approximately 32° F. and approximately 70° F. in one embodiment, or between approximately 32° F. and approximately 50° F. in another embodiment, when the biocontrol agent is applied. One can apply the biocontrol agent to bare soil and / or on plants present in the area being treated. One can apply the biocontrol agent in any manner, including spraying, broadcasting, or injecting into the soil.

[0013]It is another object of this invention to have a method for controlling the growth of annual bluegrass and / or rough bluegrass in an area in need of treatment by applying a biocontrol agent in an amount effective to control the growth of annual bluegrass and / or rough bluegrass to the area. It is a further object of this invention that the biocontrol agent contains an agriculturally acceptable carrier, and P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), or P. fluorescens biovar A strain LRS12 (NRRL B-50853), or combinations thereof; and optionally a herbicide and / or a fertilizer, where P. fluorescens strain LRS12 (NRRL B-50853) controls the growth of both P. annua L. and P. trivialis. It is another object of this invention that the agriculturally acceptable carrier can be a seed from one or more desired plants, rice, talc, one or more carbohydrates, one or more polysaccharides, one or more polymeric porous materials, milk, water, medium, and pellets made from a cereal grain flour or meal. The concentration of the bacteria applied to the treated land ranges between approximately 105 to approximately 1011 cfu bacteria per area in need of treatment. For one alternative embodiment, if one single bacterial strain is present in the biocontrol agent, the bacteria's concentration is approximately 108 cfu bacteria per area in need of treatment. For another alternative embodiment, if two or all three strains of bacteria are present in the biocontrol agent, the concentration for each strain of bacteria ranges from approximately 107 to approximately 108 cfu bacteria per area in need of treatment. It is a further object of this invention that the application of the biocontrol agent occurs when the soil is moist (i.e., after rain or irrigation) or prior to irrigating the area in need of treatment or when rain is anticipated to occur shortly after application of the biocontrol agent. It is another object of this invention that the air temperature in the area in need of treatment should be between approximately 32° F. and approximately 70° F. in one embodiment, or between approximately 32° F. and approximately 50° F. in another embodiment, when the biocontrol agent is applied. One can apply the biocontrol agent to bare soil and / or on plants present in the area being treated. One can apply the biocontrol agent in any manner, including spraying, broadcasting, or injecting into the soil.

[0014]It is another object of this invention to have a kit for the control the growth of annual bluegrass and / or rough bluegrass growth, which has one or more containers containing a biocontrol agent effective in controlling annual bluegrass and / or rough bluegrass root growth or germination; optionally a container containing a herbicide; optionally a container containing a fertilizer; and instructions for applying the biocontrol agent to the area in need of treatment. The biocontrol agent contains an agriculturally acceptable carrier and one or more of the following Pseudomonas fluorescens strains: P. fluorescens biovar B strain XJ3 (NRRL B-50851), P. fluorescens biovar B strain XS18 (NRRL B-50852), and P. fluorescens biovar A strain LRS12 (NRRL B-50853), where P. fluorescens strain LRS12 (NRRL B-50853) controls root growth or germination of both P. annua L. and P. trivialis. It is another object of this invention that the agriculturally acceptable carrier can be a seed from one or more desired plants, rice, talc, one or more carbohydrates, one or more polysaccharides, one or more polymeric porous materials, milk, water, medium, and pellets made from a cereal grain flour or meal. The amount of P. fluorescens in its container is such that between approximately 105 to approximately 1011 cfu P. fluorescens can be applied to the area to be treated. For one alternative embodiment, if one single P. fluorescens strain is present in the biocontrol agent, it is present in an amount such that approximately 108 cfu P. fluorescens can be applied to the area to be treated. For another alternative embodiment, if two or all three strains of P. fluorescens are present in the biocontrol agent, each bacterial strain is present in an amount such that approximately 107 to approximately 108 cfu per bacterial strain can be applied to the area to be treated.

Problems solved by technology

Because annual bluegrass is a grass weed growing with turfgrass, selective control is difficult.

A few post-emergent herbicides reduce Poa annua L. growth, but they could also kill desirable turfgrasses.

As such, usage of these post-emergent herbicides are limited.

Pronamide can be used in warm-season turfgrass for established annual bluegrass, but it is slow acting.

Golf-course managers have few tools to combat Poa annua L. and the invasion of this weed often means that greens must be ripped out and replaced every ten years.

However, P. fluorescens strain WH6 and other related species failed to reduce germination of annual bluegrass in the field.

Thus, information about microbial treatments for control of weeds other than annual bluegrass cannot be used to predict strains of microorganisms that would reduce annual bluegrass under field conditions or predict criteria for selecting such strains.

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