What’s an efficient vegetable?” you may ask. To put it simple, one that can grow in any variety of circumstances.
I must disagree with his use of "efficiency" . What he seems to be defining is easy to grow and adaptable. While these are good qualities in themselves, efficiency is defined as calories in terms of area required for production, water usage or amino acids, vitamins and minerals produced. In the dry west, water should be a definite concern. In the more watered east, it may well be cultivation area as in how much land is available, how much can be hand cultivated and fertilized. What nutrition is being supplied along with sufficient calories. You might figure in ease of preservation, potatoes and grain are much more easily stored in bulk than eggplant or cucumbers.