Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Alternative treatments

Some alternative treatments e.g. manure-based compost, plant and seaweed extracts, micro-organisms and existing products reduced blight infection to variable extents in the laboratory/glasshouse assays but much less so under field conditions. Efficacy of a range of these novel and commercial compounds was unaffected by dose rate or formulation. Low doses of copper products were almost as effective as full rates and far more effective than copper-free compounds. Underleaf spraying gave more uniform spray application but no improvements in blight control with either copper-based fungicides or alternatives. Timing of application is likely to be more important than method.

Acceptable levels of blight control might be achieved by using lower doses of copper-based fungicides (i.e. of the order of 2 kg/ha/year of elemental copper) than those which are currently permitted, especially when applied according to decision support systems. Further research is needed to test this and the most effective application strategy (timing and amounts) where such reduced rates are to be used. Where current national legislation and organic standards allow, this approach may offer an interim solution to the late blight problem in organic potatoes until fully effective and acceptable alternatives become available.

Reported by

Federal Biological Research Centre for Agriculture and Forestry (BBA)
BBA, Heinrichstrase 243
64287 Darmstadt