Weeds (including forest and aquatic weeds) and parasitic higher plants; their deleterious

effects, control, occurrence and distribution;

Plants poisonous to man and useful animals;

Resistance to weed competition;

Ecology, structure, physiology, biochemistry and taxonomy of weeds;

For: culture and harvesting of seaweeds, see M12

environmental damage by herbicides, See T01

residues of herbicides:

in air, soil, water, See T01

in feeds, see Q53

in foods, see Q03

toxic effects of poisonous plants on useful animals, see L74

toxicity of herbicides:

to humans, see T10 to useful animals, see L74

to useful plants, see H50