The Ministry for Primary Industries says most growers are playing by the rules when it comes to the use of chemicals on their crops.
MPI on Friday released an update on its annual Food Residue Surveillance Programme.
It says of the 247 samples of fresh unwashed produce tested in the past six months, 11 failed to comply with maximum residue limits.
The programme tests for 350 chemicals being used on a range of crops, with a focus this year on eggplants, lemons, walnuts, hops, spring onion, pumpkin, asparagus and olive oil.
MPI food assurance manager, Dr Paul Dansted, says he's pleased with the level of compliance though he says there's still room for improvement.
Dr Dansted says one organic lemon sample tested positive for insecticides and that case has been referred to the Commerce Commission.
MPI will issue a final report on the Food Residue Surveillance Programme in August.