This is a very innovative and enabling idea.The present capacities and costs however maybe a problem. It would be interesting to compare the energy requirements to manual harvesting . This might prompt the need for a new method of harvesting including modification of the pants themselves. Another attractive feature of your proposal is that . it is portable and can be manually adjusted to "harvest" maximum solar energy during its idle time..
I think it is a very useful contribution for the agricultural field. Using the solar tractors many problem can be reduced. If the solar pumping system is also adopted by the former's then it will reduce the many problem of electricity also.