Activity continues to ramp up at the Pukekohe Research and Demonstration Farm this season, with integrated pest management (IPM) approaches being demonstrated in barley, lettuce, onions and sweet corn.
The A Lighter Touch-Vegetables NZ sweet corn trap crop trial carried out last summer will be repeated and refined, with the November planting date aligning with regular commercial timing in the region. The trial uses a trap crop as a central strategy in an IPM approach targeting green vegetable bug (GVB), a significant crop pest in sweet corn.
The trap crop, made up of species attractive to GVB, is planted around the outside of the sweet corn, with the goal of aligning the flowering and seeding time of the trap crop with the sweet corn crop. When GVB migrates into the crop, the pest encounters the flowering and seeding trap crop first. A non-planted area is maintained as a barrier between the trap crop and the sweet corn to encourage the pest to stay and feed in the trap crop.
Soybean will be removed from the trap crop mix this season, due to its smaller size, reduced flowering and seed set under canopy pressure. Alternative strategies will be explored for managing weeds and lodging (where the corn plants fall over) which could create a green bridge (for pests) between the trap crop and the sweet corn crop.
The sweet corn crop with annual species used as trap crops, established at the Pukekohe Research and Demonstration Farm last year. Credit: Olivia Prouse.
Next steps in the ALT-Vegetables NZ-Onions NZ biodiversity project at the farm are focused on providing evidence of the impact of perennial native planting in supporting pest management by providing food and shelter for beneficial insects.
Spring and summer lettuce crops will be grown sequentially in a paddock with the perennial native planting down one side. Bioeconomy Science Institute (BSI), Plant & Food Research group, will be monitoring both beneficials and pests at intervals across the paddock, evaluating predation and parasitism of pests in the crop as compared to a standard lettuce crop without biodiversity planting.
With the focus on validating the impact of the perennial planting, other biodiversity components, such as the annual flower strips, will not be implemented as part of pest management in the lettuce crops.
Native perennial plantings alongside vegetable crops at the Pukekohe Research and Demonstration Farm. Credit: Olivia Prouse
Educational IPM workshops being hosted at the farm by Vegetables NZ will hold field walks in the spring lettuce, enabling growers and crop protection advisors to scout and discuss crop management next steps alongside the project team.
Future management of spring barley will also be in focus at the farm this season, with the Foundation for Arable Research (FAR) demonstrating reduced input spring barley systems for the northern North Island.
The barley will be drilled in two blocks to enable a comparison of current best practice with a future management approach involving IPM with a focus on reduced agrichemical inputs.
FAR’s future management approach aims to demonstrate how the integration of new crop protection tools can reduce agrichemical use and produce a successful yield and margin. The future management approach includes:
- resistance management strategies,
- non-chemical tools such as a biostimulant seed treatment,
- monitoring the ratio of beneficials to aphids as a basis for spray decisions, rather than calendar spraying,
- use of selective chemistry, rather than broad-spectrum products, and
- rationalising the number of fungicide applications.
Last season’s barley crop being harvested at the farm. Credit: Andrew Luxmoore.
Another innovation at the farm is a trial involving the use of a BioScout unit to support better disease management decisions. The unit is one of three funded by Te Ahikawariki Vegetable Industry Centre of Excellence (VICE), with the support of Vegetables NZ, Onions NZ and Potatoes NZ. A Lighter Touch is supporting the trial by providing land for the onion crop in which disease is being monitored.
A BioScout unit has been set up to collect air samples from 2m above ground, taking microscopic images of particles in the air and using artificial intelligence to analyse them to see if they carry disease spores. It is being tested as a decision support tool for stemphylium leaf blight (SLB) management in onions.
In one zone of the trial, information from the BioScout unit will be used to target control when the disease is present, rather than calendar spraying. In a second zone, the crop will be managed with a standard fungicide programme, and a third zone will be an untreated control, where no SLB focused products will be used so peaks in disease can be determined, and used for comparison against the BioScout data.
Onion crop at the Pukekohe Research and Demonstration Farm. Credit: Andrew Luxmoore.
Data from the BioScout unit at the research and demonstration farm and two other units located on commercial growers’ properties will be used to build a picture of how accurately BioScout can predict the disease and whether it can be used for decision-making in SLB management.
Updates from all of these projects at the farm will be shared via the ALT newsletter and on the project page of the ALT website.
