How about a crop-dusting autogyro?Some ex-military types got converted for crop-dusting: the Lysander springs to mind but there may be others. Storch? Hs-126? Swordfish?
Supposedly platforms such as the MiG-21 were developed to have spray tanks for biological warfare. What about one converted for civilian crop dusting use...when you need that back field sprayed right fucking now!
A-10...... I mean, just 'cos it's got a big wingspan of course, no other reason.........
How about a Stuka? Say they were supplied to, or built under licence in, Spain like the Me-109s, then sold off into private hands.
The Mars just might be ok for dusting the larger US farm fields ?
I always kind of liked this image:net photoSpray for the locusts and bugs and keep the nose gun for rodents.
just mix'n'match major components for a new duster ....
In New Zealand the RNZAF did some trials with Bristol Freighters that were later converted back to military standard. Their role being taken over by DC-3's.Sorry no pictures.