Food and drug retailers were the worst performers of the day on Wednesday after ING downgraded its ratings on two of the sector heavyweights.The Dutch broker this morning cut its recommendation for Tesco from 'hold' to 'sell' and cut its target price from 320p to 285p, saying that the supermarket should make more price cuts to retain its customers."We find that Tesco has become more expensive relative to key challenger Asda and in the wider market since its profit warning in January," said analyst Jan Meijer.Morrisons was also taken down a peg by ING, having its rating reduce from 'buy' to 'hold' and target cut from 380p to 290p. The broker cited the recent slowdown in sales growth and a lack of short-term catalysts.Top performing sectors so far todayAutomobiles & Parts 4,381.54 +2.07%Industrial Metals & Mining 2,895.16 +0.91%Industrial Transportation 2,350.26 +0.72%Mobile Telecommunications 4,186.81 +0.57%Tobacco 38,399.14 +0.56%Bottom performing sectors so far todayFood & Drug Retailers 3,924.87 -0.86%Life Insurance 4,197.05 -0.74%Insurance (non-life) 1,488.19 -0.58%Electronic & Electrical Equipment 3,277.80 -0.42%Banks 3,673.31 -0.32%BC