With a grove between 10 and 50 acres you will have an easier time getting a professional pesticide applicators to treat your trees during periods of high demand. However they can make more money by staying in an even larger grove, thus reducing time spent traveling and setting up, not to mention the increased liability and regulatory responsibility for having more customers. If you can get other growers in your area to spray at the same time you will have more influence in getting your grove done in a timely manner.