The effect of Tagetes spp. on the hatching of an Italian population of Globodera rostochiensis.

Leaf and root extracts, separately or in combination, and root leachates, from Tagetes erecta and T. signata, showed no nematicidal effects when tested on the hatching of an Italian population of Globodera rostochiensis. Aqueous extracts showed only inhibiting effects. Antagonist effects between leaf and root extracts of T. erecta were very evident on inhibition of egg hatching.