A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a multi-site inhibitor or a strobilurin inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a multi-site inhibitor or a strobilurin inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a multi-site inhibitor or a strobilurin inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi, wherein the at least one fungicide is a succinate dehydrogenase-inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi, wherein the at least one fungicide is a succinate dehydrogenase-inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi, wherein the at least one fungicide is a succinate dehydrogenase-inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a fungicidal sterol biosynthesis-inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a fungicidal sterol biosynthesis-inhibitor.

A fungicidal composition containing a fungicidally effective amount of the compound of Formula I:

##STR00001##

5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one, and at least one fungicide to provide synergistic control of selected fungi wherein the at least one fungicide is a fungicidal sterol biosynthesis-inhibitor.

A fungicidal composition comprising a mixture of components (A) and (B), wherein component (A) defined by formula (I) is a 3,4-dihydroisoquinoline having a 1-benzimidazolyl substituent and component (B) is selected from difenoconazole, hexaconazole, azoxystrobin, fludioxonil, cyprodinil, fluazinam, isopyrazam, pyroquilon, tricyclazole, chlorothalonil, propiconazole, penconazole, fenpropimorph, fenpropidin, sulphur and Bacillus subtilis var. amyloliquefacien s Strain FZB24. The use of the composition in agriculture or horticulture for controlling or preventing infestation of plants by phytopathogenic microorganisms, preferably fungi.