JERUSALEM - The lifespan of plants, fruit and vegetables could be doubled with a dose of the impotence treatment drug Viagra, but the cost would be punitive, an Israeli university researcher said. "Plants aren‘t all that different from people," said Professor Yaacov Leshem, a plant physiologist at Bar-Ilan University who has headed the research project over the past few months. "It helps prevent ageing and helps them stay erect." Leshem found that two or three milligrams of Viagara dissolved in water when applied to a cut flower helps slow down the emission of ethylene, a gaseous hormone that causes fruit, vegetable and plant ripening, ageing and eventually spoilage. Bar-Ilan University and the University of Newcastle in Australia have registered a patent on the findings, which they believe could revolutionise packaging and storage of produce. The only drawbacks, Leshem said, are the cost of the process with Viagra retailing at around 65 shekels (about $16) a tablet and the possible effects on consumers of the Viagra-bred legumes. "This is very, very new," Leshem said. "It could certainly affect impotency of people who eat them but also have a negative influence on elderly people if they have health complications. Our recommendation for the time being is that Viagra only be safely applied to cut flowers. People don‘t tend to eat roses." Viagra is made by U.S.-based Pfizer Inc.