Abstract: A method and composition are provided for combating fungus of plants wherein there is applied to the fungus a biologically-active pyrimidine derivative having the formula: ##STR1## or salt thereof, wherein X is an atom of oxygen or sulphur; R.sub.1 is hydrogen; R.sub.2 is hydrogen, alkyl or alkenyl containing not more than 6 carbon atoms; phenyl or halo- or alkyl-substituted phenyl, cyclohexyl or acetyl; R.sub.4 is alkyl containing not more than 6 carbon atoms or a phenyl radical; R.sub.5 is hydrogen, or alkyl or alkenyl containing not more than 6 carbon atoms; R.sub.6 is alkyl containing not more than 6 carbon atoms or phenyl.

Abstract: Pyrimidine derivatives are provided wherein the 6-position carries the group OSO.sub.2 NR.sup.5 R.sup.6 and the 2-position carries the group NR.sup.1 R.sup.2. R.sup.1 and R.sup.2 are preferably hydrogen or lower alkyl but both are not hydrogen and R.sup.5 and R.sup.6 are preferably lower alkyl, although these groups may form a cyclic ring. The 3-position and 4-position are preferably substituted with lower alkyl, although lower alkynyl or alkenyl may be used. The derivatives are compounded into compositions for combatting fungal pests.

Abstract: 2-Ethylamino-4-methyl-5-n-butyl-6-hydroxypyrimidine and salts thereof which are useful in combating plant diseases.

Abstract: Fungicidal pyrimidine derivatives and the use thereof in combatting plant diseases. Representative derivatives are 2-dimethylamino-4-methyl-5-n-pentyl-6-hydroxypyrimidine and 2-dimethylamino-4-methyl-5-n-propyl-6-hydroxypyrimidine.

Abstract: Fungicidally effective 2-amino pyrimidines bearing in the 6-position a carboxyl- or sulphonyl-esterified hydroxy or mercapto group; or salts thereof.

Abstract: 2-Amino pyrimidines bearing in the 6-position a carboxyl- or sulphonyl-esterified hydroxy or mercapto group; or salts thereof. Processes for making these compounds and compositions and methods for using same to combat pests are also disclosed.