Concept:The principles of crop production are the steps carried out to grow a crop: land (site) selection, land preparation, planting, cultural practices such as pest and disease control, and harvesting.
Explanation:Land selection, seed planting and pest and disease control are carried out in growing the crop on the field.
Processing (drying, threshing, milling and so on) is a post-harvest activity done after the crop has left the field, so 'harvesting and processing' is the item that does not belong with the principles of crop production.
Answer:Option D (harvesting and processing)