Wheat prices fell on Wednesday, as the US dollar against most currencies, amid focus on the weather conditions in South America, especially Brazil and Argentina.

Agricultural commodities drew support this week from optimism about the global economy and demand, after Pfizer and the German biotech firm BioNTech announced that their vaccine was more than 90% effective in preventing the coronavirus.

Investors in agricultural commodities are following the weather conditions in southern Brazil and northern Argentina.

Traders and analysts forecast a drop in areas planted of grain in South America due to dry weather.

The dollar index rose against a basket of major currencies by 0.3% to 93.04 points as of 21:24 GMT, after hitting a high of 93.1 points and a low of 92.6 points.

Wheat December futures fell 1.7% to $5.98 per bushel, with a day high of $6.13, and a low of $5.95.