Increasing resin content in Scotch pine (Pinus silvestris) by diquat and paraquat injections

agricultural chemicals application methods arbre pour bois de construction conifere conifers crops cultivos economic plants gimnospermas gymnosperme gymnosperms injection injection d'arbres methode methods pinaceae pinus pinus sylvestris plant growth substances plantas plante plante de culture plante pour construction plants productos productos de origen vegetal products produit produit agrochimique resinas resine resins structural crops timber trees tree injection vegetable products