 By the end of the twentieth century , the mechanics of how dew condenses were much better understood . The key insight was that low @-@ mass collectors which rapidly lose heat by radiation perform best . A number of researchers worked on this method . In the early 1960s , dew condensers made from sheets of polyethylene supported on a simple frame resembling a ridge tent were used in Israel to irrigate plants . Saplings supplied with dew and very slight rainfall from these collectors survived much better than the control group planted without such aids – they all dried up over the summer . In 1986 in New Mexico condensers made of a special foil produced sufficient water to supply young saplings . 
