https://thesaker.is/briefing-analysis-of-documents-related-to-the-military-biological-activities-of-the-united-states-on-the-territory-of-ukraine-may-11-2022/

.. it was noted that Ukraine had sent a request to the manufacturing company regarding the possibility of equipping the Bayraktar drones with aerosol equipment.

In addition on March 9, three unmanned aerial vehicles equipped with 30-litre containers and equipment for spraying formulations were detected by Russian reconnaissance units in Kherson region. At the end of April, 10 more were found near Kakhovka.

Regarding the latter, is that believable? In needs some evidence of course, although it is highly likely : ).