Soybeans fell to a 13-month low in Chicago amid concern the debt crises in the U.S. and Europe may be eroding crop demand. Corn and wheat dropped.

U.S. soybean exports in the marketing year begun Sept. 1 are down 33 percent from a year earlier, according to the Department of Agriculture. Shipments have slid 19 percent for corn and 5 percent for wheat, USDA data show. Investors may be avoiding agricultural commodities until the outlook is clearer for the U.S. and European economies.

"We're seeing a continued level of concern about the health of the global economy," said Sudakshina Unnikrishnan, an analyst at Barclays Capital in London. "We're not seeing much support from the fundamental side, either. Weekly export sales are off the past few weeks."

Eoin Treacy's view In an environment where an increasing number of investors are worried about the global economy's growth prospects commodity prices have generally underperformed. The un-weighted Continuous Commodity Index peaked in April and has posted a succession of lower rally highs since. It dropped below the 200-day MA in September, encountered resistance in the region of the trend mean in late October and is falling towards the early October low. A sustained move above 615 is required to begin to question the consistency of the medium-term downtrend.

In the grain and bean complex, soybeans failed to sustain the breakout to new recovery highs in early September and quickly dropped to the lower side of the range before breaking downwards. It rallied briefly in early October and posted a new reaction low today. A clear upward dynamic will be required to check current scope for a further test of underlying trading. Corn has fallen to test the lower side of a developing type-3 top. Wheat is currently testing the lower side of a yearlong range. Oats is extending its downtrend and approaching an area of potential support in the region of the upper side of 2009/10 base. Rough Rice has fallen for four consecutive weeks and dropped below the 200-day MA. It is oversold in the short-term as it approaches a potential area of support near $14. An upward dynamic would confirm the return of demand in this region.

Cocoa hit a 33-year peak near $3750 in January and has been trending lower since. It is somewhat oversold in the short-term but a sustained move above $2800 would be required to question the progression of lower rally highs and medium-term supply dominance. Arabica coffee has returned to the region of the 200-day MA but needs to break the progression of lower rally highs to question medium-term supply dominance. Robusta Coffee has posted a sequence of lower rally highs since July. Sugar peaked in February and contnues to trend lower. It broke its 18-month progression of higher reaction lows this week and a sustained move above 28.5¢ would be required to question supply dominance. Orange Juice has been a relative outperformer but needs to hold above the $170 area if the short-term upside is to continue to be given the benefit of the doubt.

A commodity sector reset appears to be underway with oil, precious and industrial metal prices also weak. This may contribute to volatility in the short-term but should also help to hasten an easing of monetary policy over the medium term particularly in Asia.