All but about 50ha of the sweetcorn crops grown with seed contaminated with genetically engineered seeds in the Gisborne and Hawke's Bay regions has been destroyed.
Biosecurity officials last week ordered 258.4ha of Hawke's Bay and Gisborne sweetcorn crops planted with 1807kg of contaminated seed to be harrowed.
All growing plants were chopped and buried.
Replanting on the cleared paddocks was suspended earlier in the week after a small patch of seed that had only just germinated was found among three-week-old plants 300mm high.
Growers have said Christmas would be the latest that affected fields could be economically re-planted with sweetcorn for the processing sector.
Mr Sangster said most growers did want to re-plant with sweetcorn but some would plant a different crop.
Rain had caused delays with work in some areas.
About 80 percent of the 57ha of affected land in Gisborne was to be replanted while about 20 percent of 201ha in Hawke's Bay would be replanted.
Syngenta, the American seed company that supplied the seed, has agreed to compensate farmers for any costs involved in the GE contaminated seed.