My name is Mick and I have a basil farm in Queensland, Australia. We do around 20 acres of basil and pick by hand for the freshbasil market. We pick on a machine which is picked and packed. Is there a harvester available which cuts the basil at a certain height then sucks it in to a bin and packed in a separate shed I have heard they use in England.
Please excuse the delay in my response. I'm deep in the middle of my own harvests right now, so I'm a bit preoccupied.
I've grown that large of a field of basil, and know what you are up against. What you want is a Draper, modified toward specific crops. I have one shown in detail in my book "Getting Started," found at
www.herbfarminfo.com The vacuum cowling would be from John Deere systems, as I would do it.
I loved my visit to Brisbane and Queensland. I was able to pick up fresh fruit off the ground, crops I had never eaten (e.g. star fruit). If you ever need an outside consultant, I'm getting older and would love to travel. "Have spade, will travel."
My Draper was purchased at a boneyard in an agricultural community for less than $1,500. I then modified it for lemon balm (40 acres). The leaf has very fragile oils that are easily lost if man-handled. We used hop kilns, but newer fan-systems from Germany (Binder) are more advanced. I could help you design specialized equipment.