U.S. Agriculture Secretary Tom Vilsack haswarned that left unchecked, aging farmers could threaten the ability to produce the food the world needs. The average age of growers in developed countries is now about 60, according to the United Nations. Japan plans to spend 4 billion yen ($36 million) in the year through March to promote farm automation and help develop 20 different types of robots, including one that separates over-ripe peaches when