"There was Cyclone Ita (which blew seeds off) then the torrential rain - it's rotting in the ground," Kumara activist Nicky Calcott said.
"What plague? Where's the proof? It's certainly not country-wide. There have always been beech masts," Ms Calcott said.
"Shame on the Parliamentary Commissioner for the Environment, shame on the Conservation Minister."
Ms Calcott was concerned it could be the "end of kea if they keep doing it;" kea have died in several Coast 1080 poison operations.
The need for the poisoning could be negated by proper forest monitoring and ground control, she said.
Farmers Against Ten Eighty spokeswoman Mary Molloy, of Hari Hari, said the beech fruiting had been "quite patchy".
The operations were to save native birds, but kea had recently been moved on to the critically endangered list.
She also said the April 17 cyclone and one of the wettest winters in years must have had an impact.
"The beech seed will be rotting on the ground," Mrs Molloy said.
Dr Smith said while some people were opposed to the use of toxins "we have to back the science if we are to save our native birds from extinction".
The Battle for Our Birds operation will target 29 forests totalling 700,000ha. It will begin this month and be completed in November. A further 14 forests covering 200,000ha are on close watch.
They involved a mix of aerial and ground control using toxins and traps, depending on the topography and practical logistics.
Dr Smith said it would involve the use of aerial 1080 poison, but did not mean record use of the toxin because bait application rates had reduced from 30kg to 1kg a hectare.
Deer repellent would be used in the Cobb Valley in Nelson, and Waikaia in Southland, to avoid by-kill within deer herds that were of particular importance to the New Zealand Deerstalkers' Association, he said.
The cost this year is between $9 million and $12 million.
In addition, Tb Free New Zealand will carry out a further 300,000ha of pest control work on public conservation land that is being co-ordinated with DoC.
'Battle for Our Birds' also involves DoC increasing its ongoing pest control work from the historic rate of 150,000ha a year to 450,000ha a year and has a total budget of $21m over five years.
- The Greymouth Star