A combine harvester drops grain into a waiting truck Bolshiye Achasary village in the Republic of Tatarstan, Russia. The plunge in oil prices that has ravaged Russia’s economy and pushed the ruble down 45 percent in the past year has helped make the country’s wheat exports more competitive and eroded the buying power of energy-rich grain importers like Nigeria and Mexico. Illustrates WHEAT (category f) by Whitney McFerron and Anatoly Medetsky (c) 2015, Bloomberg News. Moved Friday, Sept. 4, 2015 (MUST CREDIT: Bloomberg News photo by Andrew Rudakov).