Biotech giant Monsanto Philippines will implement stricter security measures when it undertakes another controversial field trial of its Bacillus Thuringensis (Bt) corn in a few weeks. A more secure trial farm is necessary, according to Liza Parreno, Monsanto's field supervisor, to prevent militant environmental groups destroying the area, as they did during the last Bt trial in Tampakan, South Cotabato, in August this year.