Combinations of biological control agents and insecticides or fungicides

Abstract

Compositions are provided that improve overall plant vigor and yield by combining agriculturally effective amounts of at least one environmentally friendly biological control agent and at least one insect control agent and or fungicide. A composition of the present invention is particularly effective in the presence of plant parasitic nematode and fungal species. Along with a benefit of reducing insect pressure, the inventive composition enhances the root system of a plant and improves the establishment of the biological control agent within the rhizosphere, thereby enhancing the effectiveness thereof. Use of a composition of the present invention leads to an overall reduction in crop losses caused by either plant parasitic nematodes or fungi and this reduction is much greater than would have been expected from application of either component alone. Methods for utilizing compositions of the present invention are also provided. Further the compositions according to this invention display synergistic insecticidal, nematicidal, acaricidal or fungicidal activity.

Claims

1. A composition comprising a biological control agent and at least one insect control agent, wherein the biological control agent is Bacillus firmus CNCM I-1582 spores, wherein the at least one insect control agent is selected from the group consisting of clothianidin, imidacloprid, and thiamethoxam, and wherein the weight ratio of the biological control agent to the at least one insect control agent is between 50:1 and 1:50, wherein the at least one insect control agent is present in an amount from about 1% w/w to about 80% w/w based on the entire composition, and wherein the ratio is based on a preparation of spores containing 10.sup.11 spores/g of spore preparation.

2. A composition according to claim 1 further comprising a fungicide.

3. The composition according to claim 1 further comprising an isoflavone or a soil inoculant.

4. A seed treatment formulation comprising the composition according to claim 1.

5. A spray formulation for drench or in-furrow application comprising the composition according to claim 1.

6. The composition according to claim 1, comprising the Bacillus firmus CNCM I-1582 spores and clothianidin.

7. The composition according to claim 1, comprising the Bacillus firmus CNCM I-1582 spores and thiamethoxam.

8. The composition according to claim 1, comprising the Bacillus firmus CNCM I-1582 spores and imidacloprid.

Description

EXAMPLE 1

(1) Experiments were designed to illustrate the ability of certain bacteria to colonize root systems. In this particular experiment, both untreated cotton seeds and cotton seeds treated with spores of Bacillus firmus (a biological nematicide) were planted in autoclaved soil to minimize natural flora. The seedlings were harvested three weeks later. Using sterile water and a stomacher, root systems were processed to recover the bacteria.

(2) While all of the samples contained multiple species of bacteria, B. firmus was only isolated from the root systems of plants grown from the treated seed. This experiment illustrated that the B. firmus, when utilized as a seed treatment, was able to grow and proliferate within the rhizosphere.

EXAMPLE 2

(3) The experiment of Example 1 was then conducted with an altered recovery method. At harvest, half of the root systems from the treated seed were rinsed in sterile water for 30 seconds and instead of using a stomacher, the entire root system was placed directly onto a tryptic soy agar plate. B. firmus was again not recovered from the untreated samples and while it was recovered from the un-rinsed root systems of plants grown from the treated seed, it was not consistently the predominant bacterial species recovered. In the rinsed root systems however, B. firmus was not only recovered but proved to be consistently the predominant bacteria species. This experiment illustrated that B. firmus, when utilized as a seed treatment, is not only able to grow and proliferate within the rhizosphere but is actually capable of colonizing root systems. Similar experiments were also conducted with other agriculturally beneficial bacteria to prove root colonization.

(4) To further substantiate that the bacteria recovered from the rinsed root systems of this experiment was the same species and strain used in the original treatment, a 500 base pair DNA analysis and RNA comparisons were performed. The results of this testing indicated that the recovered bacteria was not only the same species but had an indistinguishable RiboPrint pattern from the bacteria used in the treatment of the seed.

EXAMPLE 3

(5) An experiment was performed to demonstrate that root system enhancements were obtained through the use of neonicotinoid insecticides. In this experiment cotton seed was treated with a fungicide base and one of three commonly used neonicotinoid insecticides: imidacloprid (sold under the trademark GAUCHO 600@0.375 mg ai/seed), clothianidin (sold under the trademark PONCHO 600@0.375 mg ai/seed), and thiomethoxam (sold under the trademark CRUISER@0.34 mg ai/seed).

(6) TABLE-US-00001 TABLE 1 Length (cm) SurfArea (cm.sup.2) Volume (cm.sup.3) T/F/C CTRL 66.11 b 11.66 b 0.17 b 47.53 b Imidacloprid 92.56 a 20.11 a 0.35 a 85.60 a Clothianidin 88.11 a 16.77 a 0.29 a 93.93 a Thiomethoxam 95.01 a 17.43 a 0.28 a 77.17 a CTRL stands for control

(7) Fifty seeds from each of the four treatments were planted. Plants were grown in standard soil in an indoor, temperature controlled, growth chamber and did not experience any significant disease or insect pressure. Seedlings were harvested 28 days after planting and analyzed using the WinRhizo root analysis system. There was no significant difference in germination.

(8) In Table 1, a comparison of Length, Surface Area, Volume, and Tips/Forks/Crossings, was made through the analysis of 40-45 plants per treatment and by averaging 10 repetitions bracketing the median for each category. Although there was variation both within the categories and within the treatments, the results showed all of the neonicotinoid insecticides provided a statistically significant growth response over the base treatment in each of the four categories based on LSD (least significant difference) and a 5% margin of error.

EXAMPLE 4

(9) The following experiment was performed to demonstrate the unexpected nematicidal benefits achieved by combining biological nematicides with non-nematicidal neonicotinoid insecticides. Soybeans (Variety-S2743-4RR) were planted with a base fungicide package and imidacloprid (sold under the trademark GAUCHO 600@62.5 gm AI/100 kg), a biological nematicide, or a combination of both. The seed were then planted in standard soil and soil infested with Soybean Cyst nematodes. Plants were harvested 28 days later (50 plants/treatment/soil type) and compared by height and by a WinRhizo root system analysis (length, surface area, volume, tips, forks, and crossings (T/F/C))

(10) TABLE-US-00002 TABLE 2 Vol- % Length SurfArea ume Height differ- (cm) (cm.sup.2) (cm.sup.3) T/F/C (cm) ence 1.) NI 281.93 66.40 1.25 497.68 26.78 2.) NI(SCN) 167.41 44.51 0.97 283.90 19.09 52.52% 3.) BN 339.82 80.01 1.52 681.73 27.90 4.) BN(SCN) 258.61 69.86 1.53 475.35 22.33 22.69% 5.) NI/BN 315.53 74.92 1.43 587.70 26.01 6.) NI/BN(SCN) 337.09 69.21 1.17 550.55 24.14 7.81% 1.) NI - Neonicotinoid Insecticide, 2.) NI(SCN) - Neonicotinoid Insecticide w/Soybean Cyst Nematodes, 3.) BN - Biological Nematicide, 4.) BN(SCN) - Biological Nematicide w/Soybean Cyst Nematodes, 5.) NI/BN - Neonicotinoid Insecticide and Biological Nematicide, 6.) NI/BN(SCN) - Neonicotinoid Insecticide and Biological Nematicide w/Soybean Cyst Nematodes

(11) The final column of Table 2 compares the total average percent difference in each of the treatments with soybean cyst nematode pressure. The plants with the insecticide alone fared the worst with stunted growth both above and below the soil and a total average reduction of 53%. The biological nematicide did exhibit nematode control having less than half the percent difference at 23%. The best overall treatment contained both the biological nematicide and the insecticide and there was only an 8% difference in overall plant development.

(12) The insecticide alone while having no direct nematicidal activity, does seem to impact and enhance the nematicidal activity of the biological nematicide.

EXAMPLE 5

(13) There are many factors to consider when analyzing yield data and comparative studies can be difficult due to the fact that environmental conditions and presence or lack of diverse disease/nematode/insect pressure(s) can fluctuate even within the same field. Although variability exists, by looking at a large enough data set, patterns begin to emerge.

(14) Table 3 illustrates averages from 10 field trials where yield was compared between a chemical fungicide control (base) and the base treatment with, a biological fungicide, a neonicotinoid insecticide, and a combination of both the biological fungicide and the neonicotinoid insecticide. Table 3 also includes 7 field trials from a similar protocol except these trials where planted in areas of known nematode infestation and a biological nematicide was used instead of the biological fungicide. These 17 trials include averages from all of the data collected from these two protocols in 2007.

(15) TABLE-US-00003 TABLE 3 Average of 10 biological Average of 7 biological fungicide field trials in 2007 nematicide field trials in 2007 Yield/ % improve- Yield/ % improve- BU ment BU ment FC 60.84 FC 41.48 FC/BF 60.82 0.03% FC/BN 42.81 3.10% FC/NI 62.07 2.02% FC/NI 42.27 1.91% FC/NI/BF 63.23 3.93% FC/NI/BN 43.67 5.27% FC = Fungicide Control, BF = Biological Fungicide, BN = Biological Nematicide, NI = Neonicotinoid Insecticide

(16) Using an equation taken from Colby's formula for synergy (found in the article Calculating Synergistic and Antagonistic Responses of Herbicide Combinations, by S. R. Colby, Apr. 11, 1966, Scientific Article No. A 1271 Maryland Agricultural Experiment Station, Department of Agronomy, University of Maryland, College Park, Md.), the expected percent increase in yield from the combination of the biological control agents and neonicotinoid insecticides (E) is calculated using the percent increase in yield obtained from the use of the biological control agents alone (P1) and the percent increase in yield obtained from the use of the neonicotinoid insecticide alone (P2).
E=P1+P2(P1(P2)/100)

(17) Applying the equation to the trials above, the expected percent increase for the combination treatment in the fungicide trials would have been 1.99% (however the actual increase was 3.93%) and the expected percent increase in the combination treatment for the nematicide trials would be 4.95% (however the actual increase was 5.27%).

(18) Having disclosed the subject matter of the present invention, it should be apparent that many modifications, substitutions and variations of the present invention are possible in light thereof. It is to be understood that the present invention can be practiced other than as specifically described. Such modifications, substitutions and variations are intended to be within the scope of the present application. As used in the following claims, articles such as a, the and so on can connote the singular or the plural of the object following.