Practices in agriculture and horticulture are increasingly being challenged for their lack of true sustainability.
At the Horticulture New Zealand conference the post-pesticide age was considered in a panel discussion aimed at kick-starting new thought processes for next-generation bio-protection in a volatile horticulture era.
Headed by Lincoln University ecology professor Dr Steve Wratten, a top global researcher on biological pest control, the panel included Foundation for Arable Research chief executive and applied plant scientist Alison Stewart, Charles Merfield of the Future Farming Centre and Robbie McCormick, technical manager for Hawke’s Bay-based Mr Apple.
The high use of damaging inputs and misuse of oil-derived products and water were key issues around the industry’s challenges, Wratten said.
Frequent pest, weed and disease invasions compound those problems, often mitigated mainly by prophylactic pesticides.
Wratten outlined the future-farming system driven by next generation bio-protection where, in terms of biologicals, NZ is miles behind the rest of the world.
“We have got to accept that whatever we do there’s no silver bullet.
“It will be a journey of hard work but a journey we have got to take.
“So how are we are going to cope in the post-pesticide era and what is bio-protection?”
It is an industry-funded centre focused on research to find natural and sustainable solutions for controlling plant pests, weeds and diseases in NZ.
The aim is to develop sustainable pest management solutions that will help NZ’s plant-based primary production to flourish while maintaining a pristine natural environment.
“It’s about harnessing the power of thriving things to manage pests, weeds and diseases – giving nature a helping hand.”
It’s as simple as shelter, nectar, pollen and prey – SNAP.
“If we have shelter we will have the insects and the bees and the wasps and the ladybugs and with the food they will survive to be the alternative prey for the invasion of new pests and weeds.
“Why do we have increasing incursion problems? Because we haven’t looked after our natural prey.”
Vineyards have put SNAP to work, planting 100-metre strips of buckwheat and phacelia between rows of grapes, growing and flowering to look after the natural prey and cut down the use of pesticides.
“Every 10 rows at $3-$5 worth of seed for 100m, it’s inexpensive, it’s environmentally friendly and its nature’s service to plants.
“While harvesting the services of nature can be a complicated story there are very strong marketing reasons that will bring true tangible benefits.
“We just have to do it. Feed the bees and the ladybugs and improve the health of plants,” Wratten said.
“The armoury we have as scientists is amazing in what we as scientists can offer to you as growers.”
In a snapshot of biopesticides for the horticulture industry Stewart said it’s about global food security, climate change protection, environmental pollution and sustainable ecosystem services.
She acknowledged the whole biological crop space is very confusing, wide and diverse with lots of terminology.
Stewart has successfully developed and commercialised a number of biopesticide technologies for the horticulture, arable and nursey sectors in NZ and the United States.
“Biopesticides are in a growth phase.
“Their value comes in yield and quality benefits, crop performance, no residues, pest resistance and perception of being better for your health.
“They are an added component to the toolbox,” Stewart said.
The US has 350 registered biopesticides, NZ has 14 biofungicides and 14 bio-insecticides, mostly used in high-vale horticulture crops.
Some of them were developed in NZ and some brought from overseas.
“We have to support the home development of biopesticide products because some crops are unique to NZ so we need to support local research and development to develop NZ-specific but at the same time we can also look at the 350 US products and see what we can utilise there into NZ as well.”
Then growers will need a lot more knowledge about how to use the products.
“We will get better results from giving the advice and demonstration trials at field days to upskill growers.
“It’s going to take a lot of time and lot of resources and the sooner we get started the sooner we will see results,” Stewart said.
Merfield has worked on both sides of the science-farming fence, starting as an organic vegetable grower Britain and NZ before joining academia in the mid 1990s.
More focused on the physics around machinery and system design he went left field in his presentation to growers with mesh crop covers as a physical barrier to pests.
“It’s run-of-the-mill, standard practice in places across Europe and Israel and gives almost complete control.
“We have had significant increases in potato yields with gross margin at the farmgate up 70% because of the physical barrier and not even a sniff of chemicals.”
Merfield said the chemical tool box is shrinking.
“The tools are getting rusty and the physics, biology and ecology toolboxes are having new tools added at an exponential rate.
“You need to pick these up and run with them as soon as possible.”
The practical control of coddling moth at Mr Apple orchards is proving a huge success, McCormick said.
Mr Apple has been working on trial control programmes using imported sterile moths, releasing 22,000 moths by drone over a 10 hectare area in 10 minutes.
“It’s all about mating disruption and we have achieved 98% reduction in wild coddling moth on one large orchard.
“While we have tried various ways of releasing the moths, going from the pushbike to the drone has proven more practical and effective.”
McCormick is keen to see regional and industry conversation around such practical control measures.
“This will be a key tool as we get into high-value market unrestricted access.”
He hopes the practical control will achieve zero tolerance.
“It’s what we are aiming for and we are into year four now. Hopefully another year of investment in this area will get down to nil.”
The challenge ahead is reducing the risk posed by wild apple trees, McCormick said.
