The present invention relates to method for increasing the level of free amino acids in storage tissues of perennial plants comprising the application of at least one strobilurin (compound A) selected from the group consisting of pyraclostrobin, orysastrobin, azoxystrobin, dimoxystrobin, enestroburin, fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyribencarb, trifloxystrobin, 2-(2-(6-(3-chloro-2-methyl-phenoxy)-5-fluoro-pyrimidin-4-yloxy)-phenyl)-2-methoxyimino-N-methyl-acetamide, 3-15 methoxy-2-(2-(N-(4-methoxy-phenyl)-cyclopropane-carboximidoylsulfanylmethyl)-phenyl)-acrylic acid methyl ester, methyl (2-chloro-5-[1-(3-methylbenzyloxyimino)-ethyl]benzyl)carbamate and 2-(2-(3-(2,6-dichlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)-2-methoxyimino-N-methyl-acetamide to the plant following the period of vegetative growth. In addition, the invention relates to the use of at least one strobilurin (compound A) selected from the group consisting of pyraclostrobin, orysastrobin, azoxystrobin, dimoxystrobin, enestroburin, fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyribencarb, trifloxystrobin, 2-(2-(6-(3-chloro-2-methyl-phenoxy)-5-fluoro-pyrimidin-4-yloxy)-phenyl)-2-methoxyimino-N-methyl-acetamide, 3-15 methoxy-2-(2-(N-(4-methoxy-phenyl)-cyclopropane-carboximidoylsulfanyl-methyl)-phenyl)-acrylic acid methyl ester, methyl (2-chloro-5-[1-(3-methylbenzyloxyimino)-ethyl]benzyl)carbamate and 2-(2-(3-(2,6-dichlorophenyl)-1-methyl-allylideneaminooxymethyl)-phenyl)-2-methoxyimino-N-methyl-acetamide for increasing the level of free amino acids in storage tissues of perennial plants.La présente invention porte sur un procédé pour l'augmentation du niveau d'acides aminés libres dans des tissus de stockage de plantes vivaces comprenant l'application d'au moins une strobilurine (composé A) choisie dans le groupe constitué par la pyraclostrobine, l'orysastrobine, l'azoxystrobine, la dimoxystrobine, l'enestroburin
