Strengthening plant protection services - phase 2 (research) Sri Lanka. Weed control in agricultural crops [herbicides]

agentes nocivos agricultural chemicals asia asie control de malezas control de plagas crops cultivos economic plants facteur nuisible herbicidas herbicide herbicides injurious factors lutte anti-mauvaise herbe malezas mauvaise herbe pest control plantas plante plante de culture plants produit agrochimique sri lanka weed control weeds