Development of Strategies for Fire Blight Control in Organic Fruit Growing

Abstract

In organic fruit growing effective control strategies are needed to prevent blossom infections by the fire blight pathogen Erwinia amylovora. Many potential control agents are under discussion and have been tested in vitro and in vivo. 19 out of 27 tested preparations showed a high efficacy against E. amylovora in vitro. Nevertheless, on detached apple blossoms only 7 of them led to a symptom reduction by more than 50%. In six field trials conducted according to the EPPO guideline PP1/166(3) BlossomProtect (82%), Myco-sin (65%) and Funguran (58%) had the highest efficiency. In 2006 and 2007, strategies to integrate BlossomProtect in spray schedules of organic apple production have been tested. The use of sulphur or lime-sulphur before or after BlossomProtect did not influence the efficiency of BlossomProtect, which showed that fire blight control is possible without compromising apple scab control. The addition of Cutisan to BlossomProtect reduced fruit russet. An alternating use of BlossomProtect and Myco-sin was shown to be possible.

Advances and Trends in Organic Fruit and Vegetable Farming Research

“…Strategies to control fire blight caused by Erwinia amylovora in organic fruits have also been proposed and tested (Sundin et al 2009;Kunz et al 2011). Foliar applications of neem oil and fish emulsion reduced bacterial spot of tomato and bell pepper (Abbasi et al 2003), and chamomile oil limited Gnomonia leaf spot (Gnomonia comari) in organic strawberry (Ristow et al 2009).…”

Difficidin and bacilysin produced by plant-associated Bacillus amyloliquefaciens are efficient in controlling fire blight disease

“…Search of an environment friendly biological alternative is a permanent task of present research. Use of Aureobasidium pullulans ("BlossomProtect") in organic fruit growing has been recommended (Kunz and Haug, 2006;Kunz et al, 2008).…”

“…Spore-forming Bacillus based bioformulations offer advantages for biocontrol because of their long-term viability (Haas and Defago, 2005). A moderate efficiency of the two Bacillus based bioformulations has been established in several field trials in the USA and Germany (Aldwinckle et al, 2002;Laux et al, 2003;Kunz and Haug, 2006) suggesting a promising potential of Bacillus sp. in control of blossom infections by E. amylovora.…”

“…Therefore, we initiated this study to select effective Bacillus strains to develop an environmentally friendly, cost effective product with a high efficiency in fire blight control. Due to the limited capacity for field testing and the high costs of field trials, a fast but reliable two step screening procedure consisting of laboratory tests in vitro and an in vivo test system with detached apple blossoms (Kunz and Haug, 2006;Pusey, 1997) was applied.…”

Effect of Alginure® (seaweed extract), Myco-Sin®VIN (sulfuric clay) and Polyversum® (Pythium oligandrum Drechs.) on yield and disease control in organic strawberries

“…In organic growing sulfuric clays are successfully introduced into the protection strategies, mainly in apples (Jamar and Lateur, 2007;Jamar et al, 2010;Kelderer et al, 2010;Kunz et al, 2011;Falta and Vávra, 2010).…”