Novel seed-based treatment for tackling flea beetle damage to protect the UK's oilseed rape production

Rapeseed (Brassica napus subsp. napus; also known as oilseed rape) is the second most important arable crop in the UK. Uses of oilseed rape range from edible vegetable oils to biodiesel and animal feed. The recent disruption of international supply chains caused by the Russia-Ukraine conflict has resulted in the prices of oilseed rape nearly doubled between February and April 2022, demonstrating the global demand of the crop and benefits for the UK growers to increase its production. However, pest pressure in the UK (e.g. cabbage stem flea beetle, CSFB) has led to 15-20% yield losses annually. Due to difficulties with crop establishment caused by CSFB and subsequent poor grower returns, rapeseed crop area has been decreasing from 530,000 ha in 2019 to 307,000 ha in 2021. Because lack of fully effective crop protection control of CSFB, growers are relying on cultural Integrated Pest Management (IPM) techniques such as later drilling and companion cropping to control the pest but had limited success. In the proposed project, we plan to test and verify a novel seed-based treatment to prevent further CSFB feeding and damage to the rapeseed tissues with extremely low agrochemical inputs, providing crop protection to mitigate pest damage for an important UK crop - oilseed rape.

Rapeseed (Brassica napus subsp. napus; also known as oilseed rape) is the second most important arable crop in the UK. The recent disruption of international supply chains caused by the Russia-Ukraine conflict has resulted in the prices of oilseed rape nearly doubled, demonstrating the global demand of the crop and benefits for the UK growers to increase its production. However, pest pressure in the UK (e.g. the main pest threat is cabbage stem flea beetle, CSFB; Psylliodes chrysocephala) has led to 15-20% yield losses annually.

We plan to test a novel seed-based JA treatment and its effectiveness to mitigates CSFB damage in both controlled and field conditions, using UK recommended oilseed rape varieties and treated with four treatment combinations (i.e. untreated control, seed treatment only, foliar treatment only, and both treatments). In this 6-month project, we propose to (1) test and evaluate whether the seed-based JA treatment is an economically viable tool that can be employed alone or in conjunction with other IPM-based methods to offer sufficient crop protection to selected UK recommended winter oilseed rape lines; (2) quantify the efficiency of the seed-based JA treatment individually and on UK recommended oilseed rape varieties; (3) verify whether the treatment impacts seed germination and early establishment and the effectiveness of the treatment that mitigates the CSFB damage at establishment, stem elongation and flowering under field conditions.

We will examine whether JA treatment will have impacts on oilseed rape seeds using seed germination- and establishment traits powered by SeedGerm and Videometer (WP1), establish field-based trials to study the effectiveness of the treatment that mitigates the CSFB damage using RGB and multispectral drones and the AirMeasurer platform (WP2), and collate research results for verification and dissemination to maximise impacts.