Burning or Freezing? The real cause of losses in Pear and Quince Fruit in Turkey

Fig. 1. Fireblgiht (Flicker 2017)

by Deniz Ozkardas, Psychology major

For most of us, freezing and burning are polar opposites, however in plant world they might be the actors in a fruit loss resulting in exportation concerns. In this blog, I will be researching two factors ice nucleation active (Ice+) bacteria and fire blight to understand how pear and quince fruits get affected in Turkey.

Fireblight (Erwinia amylovora) is a disease affecting members of the rose family which causes a dying-back and browning of shoots and leaves.

However, quinces are less suscpectible to this than many other members of the family (Don, p.403,2009).

Ice nucleating organisms is a group (such as Pseudomonas syringae) that ‘attack plants through frost damage using specialized ice-nucleating proteins’ (Pandey et al,2016). The researchers also note that information such as structure are limited although their interactions with biology and environmental science are bring researched such as fireblight.

– Effect of Fireblight in Turkey

Samsunlu55 : a local from Samsun Turkey in the forum Agaclar.net for plants wrote that the disease stopped the production of Quince fruit. (Latin: Cydonia vulgaris Pers.)  He literally described the process as flowers burning with their leaves and their fruits.

The exportation of pears declined from 677.843 to 419.445  kg in one year (April 2016-April 2017) . Interestingly, the pear exportation was 192.025 kg in April 2015 and was in steady increase since April 2013.

Bursa, which is in the recent rise for pear growth with exports to Germany, Russia, France, Italy and Middle East (Bursadabugun,2017), had frostiness in the region affecting it’s growth heavily.

Yogurt, who is a farmer in Bursa, says that they can’t even eat pear let alone exporting and the rendement decreased from 150-200 to 20-30 kg in their establishment. A 2007 post from Agaclar.net also commented that he lost 800 pear trees in 3 years at Sapanca, Turkey.

– Ice Nucleation Active Bacteria and Firebight

Lindow et al (1996), noted that the ability of supercooling in pears (process preventing frostation) is blocked by ice nucleation active (Ice+) bacteria appearing in many regions. It was furthermore noted that this disease can occur at the same time with fire blight.

This raises the question of whether fireblight or ice nucleation active bacteria are the one to blame. Still, it affects the produce from local to international scale (through commerce) and impacts economy.



Agaclar.net. (2017). Ates yanikligi hastaligi (Erwinia amylovora) – agaclar.net. [online] Available at: http://www.agaclar.net/forum/genel-bitki-koruma/4868.htm [Accessed 4 Jun. 2017].

Bursada Bugün. (2017). Bursa’da armut verimi düştü. [online] Available at: http://www.bursadabugun.com/haber/bursa-da-armut-verimi-dustu-705553.html [Accessed 27 May  2017].

Don, M. (2009). The complete gardener. 1st ed. London: Dorling Kindersley.

Flickr. (2017). Fire blight. [online] Available at: https://www.flickr.com/photos/oregonstateuniversity/13742920923 [Accessed 4 Jun. 2017].

Pandey, R., Usui, K., Livingstone, R., Fischer, S., Pfaendtner, J., Backus, E., Nagata, Y., Fro hlich-Nowoisky, J., Schmu ser, L., Mauri, S., Scheel, J., Knopf, D., Po schl, U., Bonn, M. and Weidner, T. (2017). Ice-nucleating bacteria control the order and dynamics of interfacial water.

Lindow, S. E., McGourty, G., & Elkins, R. (1996). Interactions of antibiotics with Pseudomonas fluorescens strain A506 in the control of fire blight and frost injury to pear. Phytopathology, 86(8), 841-848.

Yms.org.tr. (2017). DEĞERLENDİRME RAPORLARI. [online] Available at: http://www.yms.org.tr/tr/istatistikler.html [Accessed 27 May 2017].


This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

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