FARGO, N.D. (AP) — American Crystal Sugar Co. CEO David Berg should testify in a federal lawsuit pitting the refined sugar manufacturers against the corn syrup industry, a federal judge ruled Wednesday after presiding over a hearing in the case.

Berg, head of the largest sugar beet processor in the country, had contested a subpoena to testify in the case, in which the refined sugar makers are suing over the corn syrup industry’s marketing claim that sugar and high-fructose corn syrup are nutritionally the same.