Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Pyrethrum plant derived material or plant derived rotenone...
Reexamination Certificate
2002-12-18
2004-12-28
Pryor, Alton (Department: 1616)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Pyrethrum plant derived material or plant derived rotenone...
C514S421000, C514S461000, C514S468000, C514S529000, C514S531000, C514S534000, C514S540000, C514S658000
Reexamination Certificate
active
06835719
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to environmentally safe pesticides, and more particularly, to a pesticide formulation containing sulfur combined with pyrethrins and/or pyrethroids for the control of plant diseases, insect pests, and mite pests.
BACKGROUND OF THE INVENTION
With the rising concern about environmental safety there has been a renewed interest in the use of naturally occurring substances, including plant oils and their derivatives, as pesticides. Substances such as pyrethrins derived from chrysanthemum flowers, azadirachtin from the neem tree, and rotenone from derris roots have become popular control actives for a variety of insect pests. Pyrethrum extract, obtained from
Chrysanthemum cinerariaefolium
, contains several esters that are very effective insecticides against a wide range of insect pests. These esters, collectively called pyrethrins, are the most common botanical pesticides in the lawn and garden pesticide market. The pyrethrins are contact insecticides, causing rapid knockdown and mortality of insects at very low concentrations. These features and their relatively safe mammalian toxicological profile have contributed to the success in the marketplace and allowed them to compete against synthetic hydrocarbons. Synthetic synergists, such as piperonyl butoxide (PBO), are commonly used to enhance insecticidal activity in commercial formulations of insecticides especially pyrethrum extract and pyrethroids. However, with the increased interest in organic gardening and recent official organic certification procedures, there has been a desire to utilize only natural constituents in pesticide formulations.
Pyrethroids are synthetic analogues of pyrethrins. They are often more toxic and last longer in the environment than pyrethrins. Pyrethroids are effective against a wide range of insects. Of the more than 1000 pyrethroids developed, about 10 are currently used in the United States. Pyrethroids are classified as Type I or Type II based on differences in basic structure and poisoning symptoms.
Sulfur, which is one of the oldest fungicides known, is also widely used today as a pesticide for the control of powdery mildews, rusts, leaf blights and fruit rots. Agrios, G. N., Plant Pathology, 4th edition, p. 208. Sulfur disrupts the metabolic processes of fungi and protects plants from disease by inhibiting spore germination. Ellis, B. W. and F. Marshall Bradley, eds., Natural Insect and Disease Control, p. 369. Sulfur is also sometimes used as a miticide. For example, Kumulus D F, a water dispersible granular fungicide, is an approved pesticide for use against rust mites. Problems associated with sulfur formulations include unsightly residue on ornamentals and the tendency of sulfur to settle out when in liquid form. Olkowski, W. et al, Common Sense Pest Control, p. 109. Some plants are sensitive to sulfur and plant damage can occur when temperatures during application are greater than 30° C.
In recent years, consumers have sought less time-consuming ways to apply pesticides. As a result, ready-to-use formulations that require no mixing are now very popular. Moreover, many consumers would also prefer to have one product that controls all pest-related problems on their plants, rather than having to make a separate application with a different product for each problem. While some combination products are currently marketed for the control of fungi, insects and diseases, these products are not always effective against all three target groups.
Accordingly, there exists a need for effective, environmentally safe, easy to use insecticides for simultaneous control of plant diseases and insect and mite pests.
SUMMARY OF THE INVENTION
The present invention is directed to an environmentally safe pesticidal liquid suspension composition including a mixture of sulfur combined with pyrethrins and/or pyrethroids. The composition can also optionally include an antioxidant. In use, the pesticidal composition is effective to control plant diseases, as well as insect and mite pests.
The composition can be prepared as a concentrate or a ready-to-use formulation. Formulations can be applied to plants, both indoors and outdoors, to control plant disease and insect and mite pests, and to reduce plant damage from such pests. The formulations can be applied to plants with minimal phytotoxicity and do not leave unacceptable levels of visible sulfur residue.
Unless otherwise noted, all percentages referred to herein are percent by weight.
DETAILED DESCRIPTION OF THE INVENTION
Pyrethrins are incompatible with many compounds and are readily degraded. Oxidation, alkaline hydrolysis and breakdown by microbes are all common modes of degradation. Degradation makes formulations containing pyrethrins, particularly water-based formulations, difficult to stabilize. Anaerobic bacteria are commonly found in sulfur formulations and can further increase the likelihood of pyrethrins degradation. The chemical nature of sulfur and pyrethrins have prevented and/or discouraged a liquid formulation containing these two substances. Sulfur could even actually accelerate the degradation of pyrethrins. Since pyrethrum extract is oil soluble or lipophylic, it must be emulsified to add into a liquid system. Sulfur, on the other hand, is a particulate and as a result requires suspension in a liquid system. Not only is it difficult to combine a particulate fungicide with an oil-based insecticide, there are additional problems associated with combining sulfur with any oil based active ingredient. Oil is known to increase sulfur phytotoxicity. As a result, commercial sulfur labels contain cautions against mixing sulfur with oil and carry warnings such as: “do not use within 30 days of an oil spray and do not mix with oil.”
In general, the present invention provides effective, environmentally safe, easy to use, liquid suspension pesticide formulations for the control of diseases, and insect and mite pests on plants. The pesticide formulation includes a mixture of sulfur combined with pyrethrins and/or pyrethroids, the combination of which is particularly advantageous in controlling plant diseases, as well as combating insect and mite pests. The composition also preferably includes antioxidants, which are effective to stabilize the formulation.
Three types of sulfur formulations are generally available: sulfur dust, wettable sulfur and colloidal sulfur. Wettable sulfur, which consists of finely ground sulfur particles and a wetting agent, is available in two types of formulations: wettable powder and water dispersible granule formulations. Colloidal sulfur, which consists of very small particle sizes which are formulated as a wet paste, is available in a liquid flowable formulation. The present invention preferably utilizes wettable powder, water dispersible granules, and liquid flowable sulfur formulations. An example of a water dispersible granule is Kumulus from BASF Corp., Mount Olive, N.J., and a wettable powder is Suffa WP 90 from Drexel. Examples of liquid flowable formulations include Red Ball Sulfur from International Sulfur Inc., Mt. Pleasant, Tex., and THAT sulfur from Stoller's Chemical Co., Houston, Tex.
The sulfur active ingredient is preferably used at an end-use concentration in the range of about 0.025% to 1.0% (250 to 10,000 ppm), and more preferably at a concentration in the range of about 0.2% to 0.4% (2000 to 4000 ppm). Concentrated formulations obviously have higher levels of active ingredients but are typically diluted prior to use. Depending on the dilution rate, concentrates may contain in the range of about 2% sulfur to 40% sulfur (20,000 to 400,000 ppm ai sulfur), preferably within the range of about 4% sulfur and 20% sulfur (40,000 to 200,000 ppm ai sulfur). Based on the disclosure that follows, one of ordinary skill in the art will readily appreciate that the concentration of sulfur may vary somewhat depending on the target pest, mode of application and application rate.
As previously stated, the composition further includes a second component which can be pyrethri
Almond David S.
Parker Diana L.
Puritch George S.
Sedun Frederick S.
Wilson Cameron D.
Nutter & McClennen & Fish LLP
Pryor Alton
W. Neudorff GmbH KG
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