Flowering plants may be key to pesticide reduction in citrus orchards
A Gisborne-based project is exploring a biological method of controlling insect pests in citrus orchards by planting undergrowth to attract beneficial insects.
“Leaving bare soil under citrus trees and intensively mowing grass strips between rows of orchards could be a thing of the past as we revolutionize our approach through strategic planting,” says A Lighter Touch Project Manager Jeff Smith.
“We have undertaken planting trials under and beside trees – ranging from flowering perennials such as clovers and alyssum to annuals such as buckwheat and phacelia. These and other plants may hold the key to helping us improve the agroecosystem and provide resources for beneficial insects to thrive, which would reduce the need for agrochemical applications.
The two-year project is part of A Lighter Touch, a seven-year, $27 million program supported by the horticulture industry and government through the Ministry for Primary Industries (MPI) Sustainable Food and Fiber Futures Fund. A Lighter Touch aims to shift the focus away from traditional crop protection by conducting research, understanding crop protection products and integrating biological and ecological processes into food production in New Zealand.
The project involved researchers from the University of Lincoln and Plant & Food Research, who extensively reviewed the current literature on how to plant to attract the natural enemies of our most persistent pests. Researchers are now translating theory into practice.
“We are testing to see what works in New Zealand conditions,” says Smith.
“The seeds were planted late last year at two test sites alongside two control sites – one in a valley and one on the plains.
“So far, we’ve seen plants in the plains struggle to establish themselves, but planting in the valley has been more successful. It was because there was more precipitation in the valley. The landowner also had sheep on the land, which trampled the seeds in the ground. In the future, we may consider fall planting to see if we can achieve a more consistent establishment.
Smith says the program routinely collects data from test and control sites, including bi-monthly monitoring of insect presence and species.
“In the spring, we will be able to assess the effectiveness of planting in the first year,” he says.
A workshop was organized with interested parties from the horticultural sector last October to present the objectives of the project.
“We’ve found that many growers want to find a better way to plant, one that relies less on chemicals,” Smith says.
“While citrus was chosen for the model system, our results should be adaptable to other perennial cropping systems.”
Steve Penno, director of investment programs at MPI, says the project provides a welcome alternative to the traditional method of spraying chemical pesticides on a calendar basis.
“The traditional practice wipes out many natural enemies that can help us fight pests, while this new method helps us work with nature,” says Penno.
“Being able to switch to this more sustainable practice would help us tell consumers a more sustainable story about where our food comes from.
“This project aligns with the intentions of the government’s Fit for a Better World roadmap for the primary sector, which seeks to find more sustainable ways to produce our world-class products in New Zealand, which in its tower will increase consumer demand and generate increased exports. Return.”
Notes for Editors
Current initiatives under A Lighter Touch include:
* In partnership with Zespri, a new IPM plan for the passion fruit leafhopper (Scolypopa australis) of kiwifruit (based at Zespri headquarters in Tauranga).
* Arable field trials as part of the Foundation for Arable Research’s proof-of-concept project to reduce aggregate agrochemical inputs in arable systems (based at FAR Headquarters in Templeton, Christchurch).
* Management of soil-borne diseases with the New Zealand Buttercup Squash Council and annual arable and vegetable crops (based in Hawke’s Bay and Gisborne).
* With Onions New Zealand, the validation of agroecological and integrated pest management (IPM) approaches for the protection of onion crops (based in Pukekohe).
* In association with TomatoesNZ, an IPM program for greenhouse tomatoes incorporating biological arthropod control agents (based in Ōhaupō, Waikato).
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