Post-harvest eradication of Venturia inaequalis by different fungicides in 2003

There are strong indications that the accidental post-harvest application of Nustar 2x on April 23 or 24 prevented normal ascospore production in leaves used for the post-harvest dip experiment. The dip experiment should be repeated.

Baycor 2x, Score 2x and 1x and Nustar 2x performed the best as post-harvest eradicants in the field experiment. Therefore, Baycor at 80mℓ/hℓ, Score at 6mℓ/hℓ and Nustar at 24mℓ/hℓ should be used for post-harvest eradication of the scab fungus. Registration for Score and Nustar should be obtained.

Chorus and Scala should be evaluated at higher rates than 60g/hℓ and 80mℓ/hℓ respectively, in order to increase the spectrum of fungicides for post-harvest eradication.

Application of post-harvest fungicides at 1x rate should be avoided. The efficacy of this rate was throughout insufficient with the exception of Score.

There are indications in this experiment as well as by data from other investigations that timing of the application of EBI fungicides has a great effect on their efficacy as post-harvest eradicant. Therefore, this aspect needs more attention.

Delan has no effect on ascospore production of the scab fungus. Therefore, it should not be used for post-harvest eradication purposes.