Reuters: Vietnam vowed to maintain current rice crop areas and boost yields to ensure supplies remain adequate in the face of demand pressures from a fast-growing population as well as the effects of climate change. The government’s pledge of security of food supplies touched a key agenda topic at two conferences that opened in Hanoi on Tuesday, bringing together more than 1,300 scientists, policymakers and traders from nearly 70 countries. With more than half of the world’s 6 billion people eating…