Ureas of the structure ##EQU1## WHEREIN X is F or OCH.sub.3 ; Y is O or NH; m is 0, 1 or 2, and n and n' each are 0 or 1, Are useful in prevention of ozone damage to plants.
Ureas of the structure: ##STR1## WHEREIN X is F or Cl or OCH.sub.3 ; Y is O or NH; m is 0, 1 or 2 and N and n' each are 0 or 1 with the proviso that if n' is 1, X is not Cl and if Y is O, X is not Cl are useful in prevention of ozone damage to plants.
结构区域:##STR1## 其中 X 为 F、Cl 或 OCH.sub.3;Y 为 O 或 NH;m 为 0、1 或 2,N 和 n' 各自为 0 或 1,但若 n' 为 1,则 X 不为 Cl,若 Y 为 O,则 X 不为 Cl,这些区域对于预防臭氧对植物的损害是有用的。