In order for small UAS systems to be productive in the US, the current minimum total spray volumes per acre stated on the various chemical labels will have to be changed. Have any manufacturer's approached the Environmental Protection Agency about reducing these stated minimums?My estimation is that it will have to be reduced from 2, 3, 5, and 10 gallons per acre total volume down to mere ounces per acre, most likely straight chemical sprayed ultra low volume "ULV".
Sorry, its $150,000 for a built one?
How about using the Ag-Striker, which is an unmanned version of the Mosquito and has a 40 gallon capacity, should cost about $50,000 for a built one?
Label aerial excerpt;
Use 2 gallons of ROYAL MH-30 per acre in a minimum of 10 gal- lons of water per acre. Do not fly at heights of less than 8 to 12 feet. Maintaining this height will give more uniform coverage and aid in preventing excessive build up of chemical on the left side of the treated swath. These heights should be reduced if cross-wind velocities exceed 2 to 4 MPH.
To compound the lack of productivity due to the high volume required there is also a temperature restriction.
Label excerpt of temp. restriction;
TEMPERATURE: ROYAL MH-30 should be applied at tem- peratures below 85°F or at temperatures below 80°F if the temperature is expected to exceed 85°F later that day.ROYAL MH-30 is water soluble and under high temperature and low humidity conditions will crystallize on the leaf surface and will not be readily absorbed into the plant.
Of course the timing of this application comes between the middle of July and the first week of August. When we are the warmest, certainly breaking 85'F every day. Generally starting at 65-70'F at 6:00 am at this time of year. Which might give you until 1000 am until it hits 80 degrees, so four hours to put this product out.
Let's say you get 250 acres of this turned in. That's 2,500 gallons gross volume to put out, in a TIMELY fashion. At four gallons a load (.4 acres per load), that's 625 loads. At 12 mph (RMAX advertised working speed) and a 20 foot swath, you would have to fly about 900 feet before being empty and needing to return for another load. That would take around two-three minutes including takeoff, etc. The only loading I have seen on video of the RMAX operation required a shutdown to remove the slide-on hoppers. Let's say another two minutes on a non-fuel load to do that and get the skids back off the ground. So four minutes per load average, if the crew followed them through the field because it would take three loads to get across one pass of our average half mile fields. At four minutes per load that's 15 loads per hour, or 6 acres. In a four hour morning you'll only get 24 acres done. That means it'll take 11 days to get the job done with one machine, or 11 machines to get the job done in a day. Since the weather isn't perfect, it would technically take longer to perform than ten days, and ten days is not an acceptable window. That'll be interesting from multiple perspectives. One is profitability. 10 gallon work is around $14 an acre cost to the grower. That means that a $100,000 machine with two operators on payroll and a support truck to insure an put gas in will gross $84.00 an hour.
Interesting to note that even if this particular product was approved at "ULV" rates, it still goes on at 2 gallons per acre without the carrier.
This is certainly worst case scenario, but it exists, and it gets done.
Closest we have seen is the gas gun and splatter gun label additions for some herbicides. This has set the precedent for low volume application but we still have a larger battle with getting this approved for aerial application. The companies may have the relevant research data to apply for the changes but will also need sufficient inducement to apply for them. In Australia we have the ability to apply for minor use permits which can then be used as evidence in an application for a label amendment.
I assume that in Japan they either didn't have minimum volume statements, or they catered the labels to the UAS with ULV statements.
I just put out a growth regulator called Palisade EC today and noticed that the label specifically prohibited ULV application by air. It'll be interesting to see how this is handled over time.
Palisade label aerial excerpt;
• Thorough coverage is necessary to provide a good, uniform effect.
• A minimum of 2 gallons of diluent per acre can be used in grasses grown for seed, cereals, and sugarcane.
• Avoid application under conditions when uniform coverage cannot be obtained or when excessive spray drift
• Do not apply directly to humans or animals.
• Do not apply through any ultra-low volume (ULV) spray system.