DuPont Pioneer has decided to forgo $13.3 million in state tax credits for a $138 million expansion that is underway because the company couldn’t promise the required creation of 305 jobs due to “market conditions.” Company spokeswoman Jane Slusark couldn’t immediately say how many jobs the laboratory, seed testing, office and soybean research expansion would create. Slusark confirmed that DuPont Pioneer has cut jobs at Johnston in recent weeks as part of DuPont’s plan to cut its global workforce by 10 percent, but she declined to say how many. DuPont Co. is now is pursuing a merger with Dow Chemical Co. to create a $130 billion company that would include an agricultural spinoff.