Fungicidal composition and method containing 2-amino-pyrimidines

A process for combatting powdery mildew which comprises applying to the locus of the plants or to the seeds thereof or to soil in which the seeds are to be planted, which plants are susceptible to attack by powdery mildew, a fungicidally effective amount of a systemically active pyrimidine derivative of the formula:

• ##SPC27##
• or a salt thereof, wherein R.sub.1 and R.sub.2 are hydrogen, lower alkyl, or lower alkenyl;
• R.sub.3 is lower alkyl;
• R.sub.4 is lower alkyl or lower alkenyl;
• X is oxygen or sulfur and R.sub.5 is hydrogen.

A process for combatting powdery mildew which comprises applying to the locus of plants or to the seeds thereof or to soil in which the seeds are to be planted, which plants are susceptible to attack by powdery mildew, a fungicidally effective amount of a systemically active pyrimidine compound, or salt thereof, selected from:

• 2-dimethylamino-4-methyl-5-n-pentyl-6-hydroxypyrimidine;
• 2-dimethylamino-4-methyl-5-n-propyl-6-hydroxypyrimidine;
• 2-dimethylamino-4-methyl-5-allyl-6-hydroxypyrimidine;
• 2-isopropylamino-4-methyl-5-n-butyl-6-hydroxypyrimidine;
• 2-amino-4-methyl-5-allyl-6-hydroxypyrimidine;
• 2-n-propylamino-4-methyl-5-n-butyl-6-hydroxypyrimidine;
• 2-dimethylamino-4-ethyl-5-n-butyl-6-hydroxypyrimidine;
• 2-diethylamino-4-methyl-5-allyl-6-hydroxypyrimidine;
• 2-diethylamino-4-methyl-5-n-butyl-6-hydroxypyrimidine;
• 2-dimethylamino-4-methyl-5-ethyl-6-mercaptopyrimidine;
• 2-dimethylamino-4-methyl-5-n-butyl-6(2-dimethylaminoethylthio)pyrimidine;
• and
• 2-dimethylamino-4-methyl-5-n-butyl-6-(2-diethylaminoethylthio)pyrimidine.