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Professor Rosemary Collier - University of Warwick. Coventry, , GB

Professor Rosemary Collier Professor Rosemary Collier

Professor, Life Sciences | University of Warwick


Rosemary Collier's research interest is in the development and application of Integrated Pest Management strategies for horticultural crops.






Diversity and pest control in horticulture - Part 1 - Rosemary Collier Impact of climate change on pests and diseases in horticulture -  Rosemary Collier Rosemary Collier - Carrot Fly Rosemary Collier - Suction trap



Areas of Expertise (8)

Pest management

Insect Biology

Pest Management in Field Crops

Pest Science

Environmental Bioscience

Crop Science


Insect Ecology

Affiliations (3)

  • Royal Horticultural Society Science Committee
  • UK Insecticide Resistance Action Group
  • European Vegetable Research Institutes Network

Selected Media Appearances (2)

With season just around the corner, plenty of reasons to celebrate British leeks

Produce Business UK  online


"The discovery of male sterility in leeks was a pivotal point in developing hybrid varieties and transforming commercial leek production," Dr. Rosemary Collier of the Warwick Crop Centre, University of Warwick, tells Produce Business UK. “Leeks are a vegetable staple in households across the globe and important to the British economy. Applied crop research at the University of Warwick continues, with the aim to make breakthroughs and improvements which will be advantageous to the commercial sector and also bring consumers a reliable supply of safe, healthy and nutritious food”...

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New monitoring scheme for diamondback moth

Fresh Produce Journal  online


“The last few weeks have been relatively cold, delaying the development of certain pests,” Collier said. “In 2016 and 2017 we caught the first carrot flies at Wellesbourne on 1 and 7 March respectively, while we're still waiting to catch the first fly of 2018...

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Selected Articles (7)

Phenology of the Diamondback Moth (Plutella xylostella) in the UK and Provision of Decision Support for Brassica Growers


2020 In the UK, severe infestations by Plutella xylostella occur sporadically and are due mainly to the immigration of moths. The aim of this study was to develop a more detailed understanding of the phenology of P.xylostella in the UK and investigate methods of monitoring moth activity, with the aim of providing warnings to growers.

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Living on the edge: Using and improving trap crops for flea beetle management in small-scale cropping systems


2019 The use of trap crops to manage pest insects offers an attractive alternative to synthetic pesticides. Trap crops may work particularly well at smaller production scales, being highly amenable where crop diversification and reduction of synthetic inputs are prioritised over yield alone. This paper describes a series of experiments. The first was to demonstrate the potential of turnip rape (Brassica rapa L., var. Pasja) as a trap crop to arrest flea beetles (Phyllotreta spp.) to protect a main crop of cauliflower (Brassica oleracea L., var. Lateman). The subsequent experiments explored two possible approaches to improve the function of the trap crop—either by separating trap and main crop plants spatially, or by introducing companion plants of tomato (Lycopersicon esculentum Mill., cv Amateur) into the main crop. In caged field experiments, feeding damage by flea beetles to crop border plantings of turnip rape far exceeded damage to cauliflower plants placed in the same position, indicating a “trap crop effect”. Neither turnip rape plants nor cauliflower as a border significantly reduced flea beetle damage to main crop cauliflower plants, although the numbers of feeding holes in these plants were lowest where a turnip rape border was used. In similar cages, leaving gaps of 3–6 m of bare soil between turnip rape and cauliflower plants significantly reduced feeding damage to the latter, as compared to when plants were adjacent. The results of a small-scale open field trial showed that a turnip rape trap crop alone reduced flea beetle damage to cauliflower, significantly so later in the season at higher pest pressures, but that addition of tomato companion plants did not improve pest control potential.

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Innovation in the UK fresh produce sector : identifying systemic problems and the move towards systemic facilitation

Agricultural Systems

2019 Innovation has been promoted to help meet the various challenges faced by the UK fresh produce sector. However, what barriers hinder the development and spread of new ideas in the sector have not been investigated. This article explores the social and economic constraints to innovation by combining the agricultural innovation systems (AIS) conceptual framework with a functional-structural analysis. Semi-structured interviews were undertaken with 32 key informants, including growers, agronomists, researchers and representatives from major retailers. The findings show that, whilst the UK fresh produce sector is highly innovative, a number of systemic problems slow or prevent the acquisition and utilisation of knowledge. The privatisation of public extension services has led to a degree of horizontal and vertical fragmentation, with increasingly ‘closed’ groups and lack of nationwide research coordination or guiding visions for the sector. Variation in business size and crop type make coordination or coherent visions challenging to establish, presenting problems for intermediary organisations in matching the supply and demand of agricultural knowledge. At the same time, a stark power asymmetry exists between suppliers and retail customers, whose policies have led to a “defensive” innovation culture and lack of trust – producer organisations represent a response to this asymmetry, as well as increasingly important factor in the (now globalised) development and diffusion of agricultural innovations. Systemic instruments to facilitate better coordination and communication are proposed, such as innovation platforms to bring together otherwise closed groups around common problems and the use of road-mapping to provide a guiding vision for the future of the sector. Retail-led grower groups also provide a means to improve trust between suppliers and customers in the sector and promote new technological trajectories.

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Using physical barriers to prevent carrot fly (Psila rosae (Fabricius)) damage in domestic production

Journal of Applied Entomology

2019 A field experiment was used to assess the effectiveness of different barriers in protecting garden‐scale carrot production from carrot fly (Psila rosae (Fabricius)) damage. Some of the vertical barriers tested were found to provide a useful method of protecting early season carrots from carrot fly in terms of the percentage of carrots free from damage but, under cumulative pest pressure of several generations of carrot fly, such barriers were found to provide insufficient protection. Gardeners should therefore completely cover their carrot crop to attain an acceptable level of control, and this was found to be especially important for carrots harvested later in the season. There were positive effects of some barrier types on yield which may be due, at least in part, to the protection given by the barriers to carrot seedlings.

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Towards new sources of resistance to the currant-lettuce aphid (Nasonovia ribisnigri)

Molecular Breeding

2017 Domesticated lettuce varieties encompass much morphological variation across a range of crop type groups, with large collections of cultivars and landrace accessions maintained in genebanks. Additional variation not captured during domestication, present in ancestral wild relatives, represents a potentially rich source of alleles that can deliver to sustainable crop production. However, these large collections are difficult and costly to screen for many agronomically important traits. In this paper, we describe the generation of a diversity collection of 96 lettuce and wild species accessions that are amenable to routine phenotypic analysis and their genotypic characterization with a panel of 682 newly developed expressed sequence tag (EST)-linked KASP™ single nucleotide polymorphism (SNP) markers that are anchored to the draft Lactuca sativa genome assembly. To exemplify the utility of these resources, we screened the collection for putative sources of resistance to currant-lettuce aphid (Nasonovia ribisnigri) and carried out association analyses to look for potential SNPs linked to resistance.

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Identification of novel pesticides for use against glasshouse invertebrate pests in UK tomatoes and peppers


2015 To inform current and future pesticide availability to glasshouse vegetable growers, the current project trialled more than twenty products, including existing industry standards, against four key pests of glasshouse tomatoes and bell peppers. These included experimental conventional chemical pesticides as well as alternative biopesticide and biorational products based on phytochemicals, microbials and physically-acting substances. The results suggest that certain biopesticide products, particularly botanicals, provide good levels of pest control, with the same being true of experimental conventional chemical pesticides not yet recommended for use against these pests on these crops. Efforts are on-going to ensure that results of the current project translate to industry benefit via new pesticide approvals.

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Can imitation companion planting interfere with host selection by Brassica pest insects?

Agricultural and Forest Entomology

2012 Companion planting with nonhosts may offer a non‐insecticidal means of controlling pests, although the results of studies can be variable and species‐dependent. The effect of companion planting on two pests of Brassica crops, Plutella xylostella (L.) and Brevicoryne brassicae (L.), was examined using Brussels sprout as the host plant and imitation cereal plants made from green plastic as the nonhost. For P. xylostella, the effect of nonhost density was also investigated. Oviposition (P. xylostella) and abundance (B. brassicae) were lower on Brussels sprout plants presented on a background of high‐density imitation cereal plants (reductions of 59% and 85%, respectively). The results are discussed in the context of host location by pest insects and the selection of nonhost companion plants for pest management. It is concluded that nonhost plants interfere with pest host selection through disruption to visual host location processes.

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