The present invention relates to the use of compositions that, when applied to citrus, are capable of controlling the psyllids Trioza erytreae and
Diaphorina citri, vectors of
bacteria of the
genus Candidatus liberibacter, which cause the
disease known as Huanglongbing (HLB), deemed to be the most destructive
disease currently to affect citrus crops worldwide. These compositions may contain, without distinction, or jointly, as
active components,
vitamin K3, soluble derivatives thereof (preferably
menadione sodium bisulphite [MSB]) or sparingly soluble derivatives thereof (preferably
menadione nicotinamide bisulphite [MNB]), with respective concentrations of between 0.0001 and 200 ppm, 0.001 and 10 000 ppm, preferably
vitamin K3 between 0.001 and 100 ppm, MSB between 0.01 and 5000 ppm, and MNB between 0.01 and 5000 ppm. Said compositions are applied preferably by spraying to the aerial part of the
plant or via the
irrigation system, and may be mixed with a variety of additives, such as organic and inorganic fertilizers, insecticides, nematocides, fungicides, bactericides, acaricides or herbicides.