Page 244 - Breeding and regulatory opportunities, Renaud

Summary

The overall objective of the research reported in this thesis was to analyse inter-

related regulatory and technical challenges in the organic seed and breeding

sector, using broccoli (Brassica oleracea var. italica) as a model crop and the US as

the location. Organic farm practices often difer substantially from conventional

practices in refraining from chemical-synthetic inputs of fungicides, pesticides

and mineral fertilisers, but also in the diversity of crop rotations, number of crops,

production area, and market outlets. Organic farming systems are based on

organically-derived inputs such as compost and animal manure and focus their

management on stimulating long-term biological self-regulatory processes

to achieve resilience for stable productivity. However, organic farmers have

fewer options to intervene in the short-term when weather or soil conditions

are not favourable for optimal crop growth. Therefore organic growers require

cultivars with stable performance across variable growing conditions over

years. Currently, organic farmers depend largely on cultivars bred for high

external input conventional farming systems. Use of organic seed as a required

farm input is a component in the overall organic certiication process. Recent

developments in the interpretation of organic seed regulation have created

tensions between farmers and seed companies as to how to provide a suiciently

diverse assortment of cultivars suited for organic agriculture while meeting the

requirements.

This research aimed to understand and analyse the tensions between farmers’

and seed companies’ interests that have been created by evolving organic

seed regulations, and identify ways to develop a domestic and international

organic seed regulation to better support organic agriculture in general and

crop improvement in particular. However, in order to be able to translate the

diverse crop requirements identiied for stakeholders in the broccoli seed chain

in the US into a strategy for plant breeders, the horticultural and phytochemical

performance of commercially available broccoli cultivars had to be established.

The research thus also studied the performance of broccoli cultivars grown

under organic and conventional farming conditions in two contrasting broccoli

producing areas (Maine and Oregon, US).The requirements of organic growers

were investigated for cultivars that allowed optimization of their production

system, and fulilled consumer expectations for high nutritional value. The

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