Elicitors and soil management to induce resistance against fungal plant diseases

Air-borne foliar diseases as well as soil-borne diseases can cause substantial losses in agricultural production systems. One of the strategies to overcome production losses caused by plant diseases is the targeted use of disease defence mechanisms that are inherent to plants. In this paper, the potential to enhance the plant's health status either by inducing resistance through optimized soil management techniques or by foliar application of inducers of resistance is explored on the basis of a literature review and results from laboratory and field experiments. In our studies, the focus was on recent research about the use of dl-β-aminobutyric acid (BABA) and an aqueous extract of Penicillium chrysogenum (Pen) as elicitors. We conclude that BABA as well as Pen can contribute to disease control strategies. The use of soil fertility management techniques to reduce diseases was explored in recent research about the impact of short- and long-term management practices on soil suppressiveness to air-borne and soil-borne diseases, with the aim to elucidate the influence of soil properties and to quantify the relative importance of site-specific vs cultivation-mediated soil properties. The results indicate that site-specific factors, which cannot be influenced by agronomic practices have a greater impact than cultivation-specific effects within the same site. Nevertheless, short- and long-term management strategies were shown to have the potential for influencing soil suppressiveness to certain diseases such as Rhizoctonia solani.