Another aspect of this is that farmers are paid by the weight of their produce, and the much weight of many crops comes from the water content. Therefore, farmers have a strong incentive to use a lot of water to "fatten up" the produce they sell.
I don't really think you have an even basic understanding about how plants grow or work.
Watering a plant in no way makes the plant magically contain more water than a properly watered plant, it just means more run off. Also, crops are often not sold by the farmer by weight, but rather by a mix of volume and average quality.
The info from my post came from someone involved in water use research. I fully believe that a lot is lost to run-off also, but how do you define "properly watered".
Is there a single set point per plant that is "optimal" and optimal by what measure? At the market, I have seen pretty large variance in the water content of different produce, often dependent on on the source.
Also, for what type of plant is volume not correlated with weight?
EDIT: The downvote of my prior post seems unwarranted. Even if it could be demonstrated that my facts were wrong, there was nothing pejorative in anything I wrote, unlike the first sentence of your reply.
