The grower, who did not want to be identified because she feared for her safety, said her orchard had been continually targeted by thieves and she was selling up due to the financial losses and emotional stress.
Former NZ avocado grower representative Mike Eagles said growers needed to take extra security precautions on orchards as fruit neared maturity.
He said gates into orchards needed to be padlocked and any suspicious vehicles should be reported to police.
"Police take these thefts seriously. Growers put a lot of effort into producing avocados and these thefts affect their livelihoods," police spokeswoman Sarah Kennett said.
If people are suspicious that avocados being offered for sale may have been stolen or have information about the theft of the avocados from the Maungatapere orchard they can call Whangarei Police on 09 430 4500 or Crimestoppers.