A total of 92 plots of cannabis have been found and 107 offenders identified during a Central District police cannabis and crime operation
That has led to 143 charges being laid across the Central District, which takes in Wanganui, Ruapehu, Manawatu, Taranaki, Tararua and Horowhenua.
Wanganui and Ruapehu had especially large numbers of plants grown outdoors because they had large remote hilly areas where plants could be hidden, police said.
There were fewer large plantations than in the past, but more small plots.
Drugs were targeted from the air and on the ground during the March operation and officers also found and recovered 26.5 kilograms of dried cannabis, firearms, cocaine, ecstasy tablets, and 53 grams of methamphetamine.
During the operation, 7415 cannabis plants were removed, the co-ordinator Detective Inspector Keith Borrell said.
More than 5000 plants of this year's haul were recovered in the aerial operation with the remaining 2118 coming from the execution of search warrants.
Most of the searches and all of the flying occurred between March 7 and 20.
One helicopter was used at a time, supported by a police ground crew and a specialist air force crew. Many of the police officers involved had previous experience with helicopter work, through their participation in search and rescue missions.
This year Central District police were the first to use an Air Force NH90 helicopter alongside the usual Iroquois. During the operation the NH90 underwent testing and evaluation in order to support future operations.
Mr Borrell was unsure how it measured up, or whether it would be used again.
"While we are slightly down from last year on plants pulled, the focus of the operation is to remove the harm that illicit drugs and organised crime cause to communities."
Constable Alan Spooner, of Waverley, was the Wanganui co-ordinator.
Together with the rural recovery there was a significant ground phase which this year resulted in 60 search warrants against drug dealers and growers.
"The annual operation starts with an intelligence-gathering phase and is followed by an aerial recovery phase using Air Force Iroquois helicopters to winch police officers into cannabis plots," Mr Borrell said.
They didn't usually find any offenders at the plots.
"Most were located when we did search warrants."
Police received information from the public which led to many of the recoveries.
Rural people were especially ready to tell police when they saw unexpected activity in their area.
"Information received directly and through Crimestoppers has also played a key role in our operation," Mr Borrell said.
"This, partnered with our enforcement activities, delivers a strong blow to illicit drug rings and helps make communities safe and healthy places to live in."
People with information about drug cultivation, manufacture or supply rings should contact their local police station or provide information anonymously by ringing 0800 555 111.