Beziehung von Blatt- und Fruchtbefall mit Braunfäule bei Freilandtomaten

Summary

There is virtually no information available on the relationship between the reaction of tomatoes to Phytophthora infestans on leaves and fruits. Late blight and brown rot of tomatoes were assessed in outdoor conditions in 2005 on 15 tomato varieties and in 2006 for 41 varieties. Leaf disease expressed as area under the disease progress curve (AUDPC) and the proportion of healthy fruit of the total fruit were used as meas-ures. In 2005, the two varieties that were most susceptible to leaf blight produced the least healthy fruit while the most resistant variety produced the highest proportion of healthy fruit. However, for the varieties with more intermediate reactions to leaf blight there was great variation in the proportion of healthy fruit with an overall insignificant rank correlation for the two parameters (Spearman). The independence between leaf blight and brown rot was confirmed for the year 2006. While these data are an indica-tion that there is a need to assess leaf and fruit resistance independently, this will have to be done under controlled conditions or the fruit from the field has to be incu-bated after removal from the mother plants to determine if there were latent infections.