ETIOLOGY AND CONTROL MEASURES OF FIRE BLIGHT IN LOQUAT

In Israel Loquat is grown intensively on about 350 hectares in open fields, under netting and in greenhouses.
The objectives of this study were to determine which part of the plant is most sensitive to infection, to evaluate the internal spread and survival of the bacteria in the plant, and to test the efficacy of various bacteriocides and horticultural practices on disease development.
The experiments were conducted during the last three seasons in commercial orchards and in trees grown in containers under insect-proof netting.
Artificial inoculation with 10⁷–10⁵ cells/ml showed that the flowers were less sensitive than the wound caused by thinning the flower clusters.
Depending on the Loquat cultivar the wounds were susceptible to the bacteria within the first 24 hours after thinning.
Fruit blight was also observed.
The bacteria were rapidly spread from the site of infection to the stem production ooze drops as the earliest symptom.
Several bacteriocides were examined in artificially and naturally infected trees.
Results demonstrated that 0.15% Starner (Oxolinic acid 20% WP) and 2% Glycocide (Hydroxyacetic acid) were most effective in controlling disease in Loquat.
Since thinning during the autumn produces susceptible sites of infection, winter thinning will be examined.
Further study will be conducted in order to determine the survival of the bacteria during the summer and the susceptibility of the different Loquat cultivars.