Auxin sprays over the top of pre-stuck cuttings is an alternative to dipping auxin treatments.

Aqueous auxin between 500 and 2000 ppm are sprayed on the leaves until runoff usually using a backpack sprayer.

Spraying auxin requires less labor and can reduce workers to auxin exposure.

However, it requires more auxin to treat cuttings with a spray that can offset cost savings in labor.

Photo of auxin spray application by a technician.

Auxin spray application.

The spray method uses an atomizer to spray the foliage.

Timing – until the solution drips from the leaves.

Concentration – 500 to 5,000 ppm.

Solution type – usually the potassium salt of IBA in water.

Effectiveness – varies by species, but when effective it reduces worker exposure and labor time.

Photos of jugs in which K-IBA is prepared in a water solution for spray applications.

K-IBA is prepared in a water solution for spray applications.