Development of improved strategies for the control of seed borne diseases
Several seed transmitted fungal diseases (including mycotoxin producing Fusarium spp.) require special attention in organic production. Also, recent pilot studies indicated that the presently available alternative seed disinfection treatments (e.g. acetic acid, organic nutrients, thermal treatments) often do not provide complete control of these diseases or may have negative side effects on seed viability. However, previous studies also showed that by choosing appropriate combinations of (a) alternative seed dressings (e.g. application of biological control agents), (b) appropriate transplant medium additives (e.g. the inclusion of Trichoderma and bark compost in Brassica transplant media) and (c) agronomic practices (companion plants, fertility and organic matter input regimes) used in organic production systems, it is possible to suppress the development of disease from seed borne pathogen inocula in field crops.
It is therefore necessary to understand the seed-borne pathogens, seed treatments and agronomic practices on disease development. Selected arable (wheat), field vegetable (Brassica) and a greenhouse (tomato) model crops (which currently experience substantial problems in controlling seed-borne fungal and bacterial diseases) have therefore been chosen to address these deficiencies in knowledge. We will carry out the following studies (sub-workpackages):
WP3.2.1 Effect of alternative seed treatments on seed-borne fungal diseases of wheat (Fusarium spp.) and tomato (Didymella lycopersici)
WP3.2.2 Effect of soil type, fertility management practices and seed infection level on seedling disease development. We will choose a range of wheat varieties showing different patterns of early development
WP3.2.3 Effect of alternative seed treatments and companion plants on the development of seed borne bacterial diseases in brassicas (Xanthomonas campestris) and tomato (Clavibacter michiganense subsp. michiganense)
WP3.2.4 Effect of transplant substrate amendments, companion plants, and in field diversification on the development of Xanthomonas campestris and pest incidence (cabbage root fly, brassica aphis) in Brassica crops
Environmental and sustainability audits and cost/benefit analyses on novel strategies developed under WP 3.2.2 will be carried out as part of Horizontal activity 1 & 2. WP3.2 will also provide important data/deliverables for WP 3.3 & 3.5 and SPs 4, 5 & 6 (see the graphic presentation)