CBOT grain futures are down to open trading, with most-active corn down 2.4%, soybeans down 1.3%, and wheat down 0.9%. The early weakness comes as traders watch how the weather situation develops into July. "The bullish reversals from last week are on the verge of being 'taken out' with prices potentially grinding lower," says Naomi Blohm of Total Farm Marketing in a note. "While weather is hot - there are chances for rain." Traders are also moving cautiously ahead of tomorrow's acreage report from the USDA, along with the quarterly stocks report. ([email protected])