The vegetables biodiversity grower champion group is expanding to include covered crop growers, with two new members adapting practices from field crops for use in the greenhouse.
Waiuku capsicum grower Peter Schreuder and Canterbury cucumber grower Rob Lindsay are both wanting to integrate and adapt biodiversity initiatives from the Vegetables NZ-Onions NZ-A Lighter Touch biodiversity project into their covered crop growing systems, and share their experiences with other growers.
Peter has a 4.7-hectare capsicum greenhouse in Waiuku, South Auckland and Rob a 1.6-hectare cucumber farm in Kaiapoi, Canterbury. Both have recently trialled using alyssum as a food source for beneficial predators supporting pest control in their greenhouses.
Kaiapoi cucumber grower Rob Lindsay.
Peter says the alyssum produces a lot of pollen and nectar which provides an additional food source for predatory biological control agents such as the minute pirate bug, Orius.
Waiuku capsicum grower Peter Schreuder.
Recent pest pressure has reinforced his thinking that biologicals are the way to go, and he is aiming to use biological control throughout his season, building in other initiatives to his growing system, as well as the banker plants at the beginning and end of each crop row.
“Last season we had the worst season in terms of pest pressure that we have ever seen, especially regarding thrips. The thrip population ended up being too high for our predators to control, so we switched to chemical control. No matter what combinations we used, nothing was effective.”
He experienced a significant drop in percentage production of top-quality capsicum, so had no choice but to do an early crop change.
“This gave us extra time to do a more thorough clean and come up with a plan for the following season,” he says.
Drawing on knowledge from the ALT programme prompted him to trial the alyssum plants, and next season he plans to implement a floral strip around the perimeter of the greenhouse.
“We want to create a natural barrier to help reduce pests from entering the glasshouse.”
Peter says small things can make a big impact when it comes to combining an integrated pest management (IPM) approach with biologicals.
Flowering alyssum as a food source for beneficial predators in the greenhouse. Credit: Peter Schreuder
“Biological control strategies are vital for glasshouse growers to maintain sustainable growing practices. We are currently using (biological control agents) Cucumeris, Persimillis, Orius and importing Limonica.
“The future lies in sustainable growing practices such as increasing the number of predators and reducing the amount of unnecessary spraying. This is why we are using more biological predators compared to previous seasons,” he says.
The Vegetables NZ-Onions NZ-A Lighter Touch biodiverse planting on vegetable farms project has demonstrated the three biodiversity components; annual flower strips and cover crops, mobile insectaries, and permanent native plantings in field crops.
Results have shown biodiversity initiatives have boosted beneficial insect numbers to support pest management, enabling a reduction in insecticide use compared with conventional crop management.
Capsicum crop in the greenhouse. Credit: Peter Schreuder
New Zealand Vegetable Council research and development manager Daniel Sutton says transferring the same principles to covered crops could lead to habitat improvements for beneficial insects, decreasing the need for agrichemicals.
“It is exciting to see the expansion of the biodiversity grower champions group – sharing what is working, what’s not and building the knowledge base around biodiversity with all types of growers.
“While it’s a bit early to hear the results of the banker plants in the greenhouses yet, we’re looking forward to following Peter and Rob’s progress through the next season.”
Find out more about project resources for growers here.
