PPPHE 2015

The symposium »Plant Protection and Plant Health in Europe« (PPPHE) is organised jointly by the Deutsche Phytomedizinische Gesellschaft e.V. - the German Scientific Society for Plant Protection and Plant Health r.S. (DPG, www.phytomedizin.org), the Federal Research Institute for Cultivated Plants - Julius Kühn- Institut (JKI, www.jki.bund.de) and the Division Phytomedicine of the Albrecht-Thaer-Institute of the Humboldt University of Berlin (www.hu-berlin.de).


This two-day symposium will be held at the traditional building of the Division Phytomedicine, Lentzeallee 55-57, 14195 Berlin (Dahlem), Germany



The 'Principle Mode of Action' of micro-organisms as agents between fertilization and plant protection

A huge amount of microorganisms are naturally involved in agricultural or horticultural production of plants. They are responsible for the nutrient transformation process and decomposition, they fulfill important roles in humus composition, improve soil structure and can serve in rhizosphere, root and phyllosphere as mutualistic symbionts.Within this micro-cosms microbial antagonists and growth promoters exist which stabilize the ecological balance in soil and aerial compartments of the agro-ecosystem. Moreover, specific microbial rhizosphere communities of plants can guarantee widely favourable conditions for the host, e.g. microbial communities of disease suppressive soils.


If such microorganisms are formulated in products targeted for use on cultivated plants, in the EU, a registration process organises the risk and efficacy assessment of these products. The assessment procedure of Plant Protection Products (PPP) is regulated by the Regulation (EC) No 1107/2009. This regulation covers the cited modes of action of antagonism, induced resistance and growth regulation, while tolerance induction is not included due to its multi-factorial causes. At present, the legal regulation of biostimulation is not harmonised within the EU but organised on national level. It is envisaged to consider the aspects of biostimulation in the revision process of EU Regulation (EC) 2003/2003 (regulation of fertilisers).


On that background a clear classification of microbial groups followed by the appropriate registration process is inevitable to place products sustainably on the market.

The idea of the symposium is to contribute to a science based definition of the ‘principle mode of action’ of microorganisms interacting with their host plants.  This  definition should be adjusted to satisfy both the requirements of science and regulation.


It is known that multiple modes of action may occur within one group of microorganism or even within one species interacting with host plants.
The ‘principle mode of action’, therefore, may depend on the intended use and desired outcome of the interaction. Furthermore, the formulation of the product and / or the conditions of application may modify the principle mode of action.

But for a formulated product, a ‘principle mode of action’ should be identified which results in a


a) direct reduction of pathogen inoculum (via competition, parasitism/predation respectively),

b) reduced infection via a plants reaction like described above (e.g. by ISR, SAR, antibiosis),

c) changed growth behavior (via phytohormonal effects) or

d) better nutritional status of the host (via enhanced nutrient availability for the host)


You are welcome to submit oral presentations or poster proposals to contribute to the discussion.