Phytoparasitica (2001) 29, 275-276

Miriam Zilberstaine, D. Shtienberg, Z. Herzog, S. Levi, H. Shwartz, D. Oppenheim and G. Kritzman (2001)
Pruning infected tissues as a tool to cope with fire blight in pears
Phytoparasitica 29 (3), 275-276
22nd Congress of the Israeli Phytopathological Society, February 12-13, 2001, Bet Dagan, Israel, lecture
Abstract: Fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of pomaceous fruit trees. The bacteria penetrate the plant through the flowers and wounds. The disease then progresses within the tree tissues, causing wilting and death of branches; if it reaches the truck, the entire tree may die. Pruning and removal of infected tissues is one of the means to cope with the disease and growers are advised to cut infected tissues ca 30 cm below the site of the symptoms. The only factor taken into account in this recommendation to prune is the pathogen. The effects of various factors related to the host on the success of pruning were tested in a series of experiments conducted in pear orchards naturally infected by fire blight. The factors were the: (i) place of pruning (removing only the infected tissues or 30 cm below the point of visual symptoms); (ii) growth habit of the tree (few, moderate number or many new branches); (iii) time of infection (spring or autumn); and (iv) phenological stage of the trees at the time of pruning (blooming, fruit set, etc.). It was found that the success of the pruning procedures is governed, to a large extent, by the physiology and phenology of the tree. Moreover, in some cases it is preferable not to prune at all (because the bacteria remain restricted to the blossom clusters) than to prune (because the cutting induced rapid progression of the bacteria within the branches). Based on the results, the recommendations to growers were modified and now host factors, as well as the pathogen, are considered.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Dani Shtienberg

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Erwinia amylovora	Pear (Pyrus)	Israel