Treatment of plants against oomycete infection

1. A method for treating plants for an infection by phytopathogenic oomycetes by contacting plants with the strain of Phoma deposited with the Collection Nationale de Cultures de Microorganismes of the Pasteur Institute on Feb. 25, 2010 under the CNCM number I-4278, a culture supernatant of said strain or a combination thereof.

2. The method of claim 1 , wherein the culture supernatant is characterized in that it comprises at least one metabolite having a size lower than or equal to a value between 0.18 μm and 0.22 μm.

3. The method of claim 1 wherein the strain or culture supernatant is characterized in that it at least partially inhibits the growth of phytopathogenic oomycetes.

4. The method of claim 1 , wherein the oomycetes is of the genus Phytophthora.

5. The method of claim 1 , wherein the oomycetes is Phytophthora parasitica.

6. The method of claim 1 , wherein the plants are contacted with the culture supernatant of the strain of Phoma.

7. The method of claim 6 , wherein the culture supernatant is obtained by:

cultivating the strain of Phoma deposited with the Collection Nationale de Cultures de Microorganismes of the Pasteur Institute on Feb. 25, 2010 under the CNCM number I-4278,

suspending the culture obtained in water,

filtering the suspension through a sieve from 0.18 μm to 0.22 μm, and

collecting the filtered solution.

8. The method of claim 7 , wherein the suspension is centrifuged between 1500 g and 6000 g for 1 to 10 minutes before filtering the suspension.

9. The method of claim 7 , wherein the suspension is centrifuged at 2000 g for 2 minutes before filtering the suspension.

10. The method of claim 1 , wherein the plants are tobacco, tomato, potato, sweet pepper, grapevine, sunflower, or fruit trees.