DR RICHARD VOLZ (Plant & Food Research)
Disease screening is a means of determining whether individual plants or seedlings are susceptible to diseases that occur in the orchard, that is obviously important from the grower perspective. We are wanting to determine which ones are very susceptible and we want to remove those from the breeding population so that we concentrate on those plants that are more resistant to those particular diseases. And in this case we are looking at the important bacterial disease fireblight. And what we have done about four weeks ago was inoculate each of these plants with fireblight by simply cutting the leaves in half when the plant was about this high or so. And in this case this plant here is showing no symptoms, its continued to grow very well. In this case the plant was inoculated at this point and the disease has caused this necrosis. It stopped growing and died back and you can see all the brown leaves, and the lesion occurring on the stem.