Economic and agronomic feasibility of organic vegetable seed production in the UK, and subsequent seed quality (OF0166)

Summary

This is the final report of Defra project OF0166. There is a longer summary at the start of the attached main report.
For many farmers and growers, a move to organic production presents major challenges. Among these, the issues regarding the use of organic seeds could yet be a stumbling block, as growers and the seed trade have reservations about using and producing them for four major reasons:
1) The availability of a wide range of organic varieties appropriate to all year round crop scheduling, and differing production techniques and markets
2) The impact of derogation on managing the supply and demand for organic seed
3) The technical issues of organic seed production
4) Maintaining high standards of seed quality, hygiene and vigour.
Three biennial vegetable crops: parsnips, winter cauliflower, and bulb onions and a small range of annual crops including lettuces, runner beans, spinach, broccoli were grown for seed production. All the crops were grown under a Spanish “Haygrove” tunnel. These relatively cheap structures allow good ventilation whilst offering protection against wet weather. All the crops were grown following organic protocols.
Seed yields were recorded, and comparisons with disease contamination, germination and vigour were made against seed of the same variety produced conventionally by the collaborating seed company. Yields were unpredictable for some crops in the early stages of the project, but this problem was overcome as techniques were better understood and more experience gained. Seed quality was generally very good for most crops, and few problems were encountered with seed borne diseases for most crops. High levels of seed surface contamination with saprophytic fungi (Penicillium and Cladosporium) may have masked the presence of other fungi. Where equivalent comparisons with conventional seedlots could be tested for disease and vigour differences were small. However, major problems were encountered with bulb onion seed production as neck rot resulted in loss of stock material (around 50% of bulbs were lost). Hot water treatments were used in this project and were found to be successful against a range of pathogens on infected onion seed. More research into organic seed treating is advocated.
The project has shown that on a small scale at least, good quality organic seed can be produced under relatively inexpensive polythene tunnels. The yields attained can be as good as those from conventional production, but there are without doubt greater risks involved. It is suggested that should diseases or pests become rampant then their control will be difficult. This project has shown that crops like onions are extremely difficult to produce, and that neck rot in particular will be a problem for the seed producer and grower. The use of tunnels is strongly supported; they can keep crops dry at harvest, they do not necessarily encourage disease build up and natural predator populations can be built up in and around them.
It can be summed up that
1) Organic seed production was found to feasible, but higher risk than conventional production
2) Seed quality differences were small
3) Costs in terms of management input were high
4) Neck rot ( Botrytis allii) on bulb onions was, and is likely to remain, a persistent problem
5) Hot water treatment was found to be satisfactory for the small volumes of seed treated. Urgent attention is needed to identify other more consistent methods than this which will satisfy Organic protocols.