George, in the 70's where I grew up in regional Victoria Australia it was a nice warm dry climate with access to plenty of water, ideal for citrus and grapes. However there was usually an aerial visit by the police drug squg annually looking for tall green herbs with a distinct 5 fingered leaf. These herbs produced a vivid white foliage on the IR film whereas the broad beans, and other nitrogen rich vegetation grown between the rows of trees and vines did not produce such a contrast.

As kids you knew when the visit was about to come as we'd have dust storms due to the number of farmers ploughing in their nitrogen rich crops early...