The R22 is an excellant aircraft to do an Ag rating in, however if you are doing it in NZ as I suspect, dont use the training operator based in Wanganui, otherwise your Ag rating will consist of flying up and down the aerodrome., learning how to spray turn and nothing on double pass , overlap etc etc and I bet you wouldnt even get to fly on an actual spray job. Go to an Ag operator that operates an R22 commercialy on a day to day basis, that way you will be trained by a competent Ag pilot who is current and has a DGPS fitted. There are a couple in the South Island.