Despite credit woes and a volatile stock market, the DuPont Co. on Wednesday reaffirmed its outlook for this year and its plan to invest in agriculture.At an investor conference on agriculture, DuPont Chairman and Chief Executive Charles O. Holliday said the turbulence in the market during the previous 10 days will not change the fundamental strategies and performance of the company. He reaffirmed the company’s earnings of about $3.15 a share for 2007, excluding a 6-cents-per-share charge for significant items in the first quarter.