MONSANTO <MTC> SAYS DEBT WAS CUT IN 1986 Mondanto Co said it has paid off two-thirds of the debt from its 2.8 billion-dlr acquisition of G.D. Searle and Co by the end of 1986. This lowered the company's debt-to-capitalization ratio from 45 pct at the end of 1985 to 35 pct, it said. The company also said that chemical sales accounted for 52 pct of its sales in 1986, down from 70 pct in 1981. This underscores its strategy of shifting away from low profit commodity chemicals in mature markets into higher value chemical businesses in high growth areas, it said.