All that single shot orthomosaic tells the farmer is where the in-field variablility is on that day, but not what causes it. And unless you are calibrating for reflectance, you won’t be able to confidently compare orthos between two dates. Unless you are a trained agronomist, and/or have scientific training in crop sciences, geography, remote sensing or related - or can partner up as a data collector for an outfit that can do the required analysis - your service (and value to the grower) stops after data collection, since you’re not qualified to provide Rxs (what multitude of soil and other factors are creating that in-field variability? You certainly can’t tell from a single orthomosaic captured on one day and the farmers know that). There are many agronomic service companies that could benefit from quality reflectance maps, but your role would be a service provider to them, not directly to the grower.