A review into both UK and overseas research suggests alternative ways to control free living nematodes for carrots and parsnips and has recommended areas to focus on for future R&D.
Dr Roy Neilson, a nematologist at the James Hutton Institute has led a review into the management of free-living nematodes after calls from growers for AHDB Horticulture to horizon scan the research.
The review highlights action agronomists and growers could consider in the short and medium term, such as tillage, rotations and monitoring, to help improve management of free-living nematodes and made additional recommendations for longer-term research funding in areas such as biofumigation, biological control and resistance breeding.
He found evidence that the introduction of set-aside in the 1990s may have helped nematode species to increase by providing a stable environment combined with a diverse host range.
Once land in set-aside was returned to production, shorter and often inappropriate rotations boosted their numbers further. If they have gone unnoticed until recently it’s because treatments aimed at other pests, notably potato cyst nematode, kept them under control, according to Dr Neilson.
He said the recent supply problems with one of the industry’s widely used nematicides is a timely reminder of just how vulnerable carrot and parsnip growers are when it comes to controlling nematodes.
“The limited research in the UK has been focused on the potential that field-grown mustards offer, but any single solution replicates the current situation of reliance on synthetic chemicals and is unsustainable in the long term,” said Dr Neilson.