Generally for pesticide (dry or liquid) , radars are recommended.
Unfortunately there are no “off the shelves” solution for a 360 avoidance system.
Based on spec of one of the few models commercially available, for 360 it would require an array of 12 Radars connected with CanBus ring to a dedicated controler that could Sequentially Scan - Process and send avoidance Mavlink Message to Flight Controler. You can expect this unit to be quite bulky,heavy and expensive.
Alternatively, you could try this experimental module that could be interesting if you have the capacity to do your own R&D : Finally Texas Instruments mm wave radar (3D Radar) IWR6843AOPEVM is working as proximity sensor