I do not collect the airmail definitives (30c, 50c, 1p, 2.50 pesos) yet I have them all on cover since they got used with the issue I am studying. Actually, this is a fairly common postal use: a 1 peso red airmail with a 15cSC.
These two have slogans. "Plant Trees":
"Farmer send sample of your harvest to the national grain commission."
