Overwinter transplant production for extended season organic cropping (OF 0144)

Summary in the original language of the document

The objectives of this project (Defra project OF0144), lead by EFRC, were to:
• identify acceptable organic fungicide products to control mildew in transplant production
• produce integrated organic transplant production systems for brassica, allium and lettuce over the autumn and winter period by identifying optimum cell/block sizes in relation to nutrient requirements and sources, growing media formulation, and supplementary feeding and watering
• evaluate developed transplant production protocols during the winter period
• undertake technology transfer and dissemination of the results
Results:
Protocols were tested for a range of crop species and varieties, growing media, cell size and feeding regimes over the three seasons under experimental and commercial conditions. It is possible to produce transplants of a suitable quality over the winter period although propagation time is generally longer than at more favourable times of year.
With respect to identifying acceptable fungicide products
• a range of fungicidal products was identified including L-Carvone, Mycosin, fennel and clove oils that showed potential in controlling mildew on a range of crop species. However the work also raised the question of the suitability of the use of such materials in organic systems which has not been resolved.
• work on spectral filters found no benefits to their use in transplant production
• cell size has minimal effect on disease spread
As far as integrated organic transplant production systems are concerned:
• production time was longer overwinter than in spring
• lettuce was relatively easy to produce in a range of media and block sizes with no supplementary feed being necessary
• similarly cabbage was relatively easy to produce although feeding was required
• cauliflower was produced using smaller cell size and full nutrient compost