Today was mildly volatile in the market with closing gains limited to soyoil and ethanol, purportedly due to their relationship to elevated petroleum prices. But that is a loose association in a market where overall demand has practically collapsed. Higher petroleum prices can be helpful in ordinary markets, but this is no ordinary market.  The price of petroleum was up a record 30 percent at one point on assertions by President Trump that he thinks he can get Russia and Saudi Arabia to agree to a production cut of 10 million barrels/day, and boastfully perhaps 15 million barrels/day. By the end of the session, petroleum was up around 20 percent.  Corn opened down but caught the petroleum bug briefly posting a 10-cent gain that...