CHICAGO: Chicago Board of Trade (CBOT) soybean futures staged their steepest rally in nearly three weeks on Thursday on growing concern that dry conditions in parts of the US Midwest would drag down crop yields, traders said.

* CBOT September soybeans ended 16-1/4 cents higher at $8.70-1/4 a bushel. New-crop November soybeans, the most actively traded contract, also jumped 16-1/4 cents, to $8.83 a bushel, a 1.9% rise that was the strongest since July 19.

* CBOT September soymeal rose $1.80 to $296.80 per short ton. September soyoil jumped 1 cent to 29.01 cents per pound.

* Building dryness in parts of the US Midwest has elevated concerns that crop yields will decline. Crop conditions are already below normal following excessive rains during spring planting.

* Fears that a prolonged US-China trade war would limit exports also weighed on prices.

* China bought a small amount of US soybeans last week ahead of the latest escalation of trade tensions with Washington in what may be the last American farm commodity sales to China for the foreseeable future.

* A jump in prices for Brazilian soybeans is putting off buyers in China, two traders said, even as the rise was driven by expected demand from the world's No. 2 economy as its trade war with Washington intensifies.

* Traders are squaring positions ahead of next week's US Department of Agriculture supply-and-demand report, which is expected to show a smaller crop and fewer planted acres.

* The USDA said private exporters sold 135,000 tonnes of US soybean meal to the Philippines for delivery in the 2019/20 marketing year.