Les traitements combinés ont un effet de synergie important sur le développement des fleurs mâles et femelles, la synergie étant relativement plus importante pour les lots ayant un mauvais potentiel de floraison comparé aux lots à bon potentiel.

Could you please translate this to English?
The two treatments combined had a highly synergistic effect on both male and female flowering, the synergism being relatively greater for the poor-flowering than for the good-flowering families.