Weather The weather was the primary focus for South America’s grain and oilseed markets last week. Argentina’s wheat yields continue to be negatively affected by the ongoing drought, and the summer crop outlook is dimming for the same reason. Different agencies are already estimating a wheat crop of 15 MMT in the best-case scenario. The effect of the frost on 8 and 9 October is now being realized and is larger than expected.  The first wheat fields are now being harvested in the north of the country with yields below expectations. In the nucleus region, yields are expected to be fall below 2 MT/ha. Finally, the south is the best performing area and yields will only be slightly affected.  Can the production estimate...