A week without water can easily kill the average person.But a garden that goes unwatered for months may produce sweeter, more flavorful fruits than anything available in most mainstream supermarkets — even in the scorching heat of a California summer. Commercial growers call it "dry farming," and throughout the state, this unconventional technique seems to be catching on among small producers of tomatoes, apples, grapes, melons and potatoes. read this artcile and news about this concept which is getting popular these days. http://www.npr.org/blogs/thesalt/2013/08/23/214884366/to-grow-sweeter-produce-california-farmers-turn-off-the-water
actually its not a new concept, this farming system is adopted in areas having an annual rainfall of approximately 15 to 20 in. (38.1–50.8 cm)—with much of the rainfall in the spring and early summer—where irrigation is impractical.