Phytoparasitica (2000) 28, 288-289

Miriam Zilberstaine, Shulamit Manulis, Frida Kleitman and S. Levi (2000)
Fire blight in loquat - etiology and control
Phytoparasitica 28 (3), 288-289
21st Congress of the Israeli Phytopathological Society, February 14-15, 2000, Bet Dagan, Israel, lecture
Abstract: Fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of pomaceous fruit trees. In autumn 1994 in Israel, a severe outbreak of the disease occurred on loquat (Eriobotrya japonica), a subtropical evergreen tree of the Rosaceae family. Little is known about the etiology and epidemiology of the disease in loquat, since most studies have been conducted on pear and apple trees. The aims of the present work were to study the disease etiology in loquat trees, survival and distribution of the bacteria, susceptibility of various varieties of loquat to E. amylovora, and means of disease control. The experiments were conducted on trees of the varieties 'Akko-1', 'Zrifin', 'Yehuda' and 'Zikim', grown in containers under insect-proof net, and in commercial orchards. Inoculations with 10⁵-10⁷ cells/ml were done on flowers and wounds (caused by thinning the flower clusters). First symptoms of ooze drops appeared 6-10 days after inoculation, on young trees grown in containers. Symptoms of browning were observed after 15-21 days in young trees and after 30 days in orchard trees. Flowers were less susceptible to infection than were wounds. The wounds were susceptible to infection up to 24 h after thinning the flower cluster in young trees and up to 48 h after in orchard trees. Studies of survival and spread of E. amylovora in loquat trees showed that the bacteria spread rapidly from the site of infection to the stem, in both vertical directions up to 50 cm from the inoculation site. The bacteria survived in the tree branches, under natural Israeli conditions, no longer than 150 days. The variety Zikim was found to be the least susceptible, and Akko-1 the most. Several bactericides were examined in artificially and naturally infected trees. Results demonstrated that 0.15% 'Starner' (oxolinic acid 20% WP) was most effective in controlling the disease in loquat, when sprayed during the first 24 h after inoculation.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
control - general

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Erwinia amylovora	Loquat (Eriobotrya japonica)	Israel