The Use of AM-toxin in Monitoring the Numbers of Air-borne Spores of Alternaria mali Causing leaf Spot in Apple Orchards
Changes in the numbers of air-borne spores of Alternaria mali causing the Alternaria leaf spot of apple were investigated in apple orchards, by monitoring their AM- toxin(host-specific toxin) producing ability. Most of the air-borne Alternaria in apple orchards were not AM-toxin producers. In culture, only about 2% of Alternaria isolates from a commercially managed apple orchards produced the toxin that was highly toxic only to susceptible leaves.