By The Associated PressGold is trading back above $1,600 an ounce after the chairman of the Federal Reserve defended the central bank's efforts to help the economy. Gold for April delivery rose $28.90 in Tuesday trading to settle at $1,615.50 an ounce. The price of gold dropped below $1,600 last Wednesday on speculation the Fed could end its bond-buying program sooner than planned. In testimony before Congress, Ben Bernanke gave no hint that the Fed might shift away from its current program. Bernanke acknowledged the risks of keeping rates low indefinitely, but expressed confidence that such risks pose little danger now. Trading in other metals was mixed. Silver for May delivery rose 27.3 cents to $29.32 an ounce, and copper for May rose 2.2 cents to $3.583 per pound. Platinum for April delivery fell $4.20 to settle at $1,616.50 an ounce. Palladium for June fell $9.60 to $741.50 an ounce. Crop prices were also mixed. Wheat rose 5.75 cents to $7.11 per bushel. Corn was up 9.25 cents to $6.9475 per bushel. Soybeans fell 3.5 cents to $14.3175. In the market for oil and gas, benchmark crude for April delivery finished down 48 cents at $92.63 a barrel on the New York Mercantile Exchange. Brent crude, used to price many kinds of oil imported by U.S. refineries, fell $1.73 to end at $112.71 on the ICE Futures exchange in London. In other energy futures trading on the Nymex: â¿¿ Wholesale gasoline fell 6 cents to finish at $3.20 a gallon. â¿¿ Heating oil dropped 7 cents to end at $3.03 a gallon. â¿¿ Natural gas rose 1 cent to finish at $3.43 per 1,000 cubic feet.