The fungus Phytophthora infestans is known to develop resistance against the metalaxyl (fungicide), commonly used in the control of potato mildew disease. There is therefore urgent need to explore the potentials of alternative fungicides which are potent, affordable, readily available, easy to prepare and environment friendly. The study was carried out to test the fungicidal potential of aqueous extracts of Rosmarinusofficinalis (Rosemary), in vitro and in vivo on two isolates of P. infestans collected from two potato producing Algerian areas: Bourkika (Tipaza City) and El Abbadia (Aindefla City). Various concentrations of crude extracts of Rosmarinus officinalis applied by direct contact in the following dilutions: 5%, 10% and 20% on medium with pea-agar (PPA), allowed the inhibition of mycelial growth of P. infestans isolates. The observed rates of inhibition exceeded 85% and the inhibitive minimal concentration (CMI) was 5%. Parallel structural modifications, caused by mycelial lyses, as well as the deformation or, and the digestion of the contents of sporangia affected the morphology of both strains from the lowest concentration. The sporulation and the germination were inhibited by this aqueous extract (100%).
For more details:www.omicsonline.org/in-vitro-and-in-vivo-effects-of-aqueous-extract-of-rosmarinus-officinalisl-rosemary-in-the-control-of-late-blight-disease-of-potato-caused-byphytophthora-infestans-mont-de-bary-in-algeria-2329-8863-1000177.php