Grass-eating nematodes have struck, Bill Wilson, the new manager for San Diego Jack Murphy Stadium told the City Council Monday. To turn the turf green in time for baseball season will take several thousand dollars in fumigating and $28,794 in new "Tifgreen Bermuda sod," Wilson said. Just a year ago, the city spent $450,000 to add sprinklers and re-sod the stadium, so council members weren't pleased at spending more. "Somebody sold us bad grass," Councilman Ed Struiksma suggested. Mayor Roger Hedgecock said the problem was in the soil. "Nematodes don't just fall out of the sky," the mayor said, noting he had had a similar problem with his tomato plants. The council voted to buy the sod and fumigate. "That grass better be green on opening day" April 15, Hedgecock warned Wilson.