Optimisation of downy mildew (Plasmopara viticola) control in organic viticulture with low copper doses, new copper formulations and plant strengtheners, results of four years of on farm research

In three different wine growing regions in Germany, due to weather and infection conditions several fungicide (copper formulations) and plant strengtheners (Myco-Sin VIN®, Kendal®, Frutogard ®) applications against downy mildew are required in order to obtain satisfactory disease control. Results of the four years of on farm trials confirmed good efficacy of the copper based substances like copper hydroxide, partly in combination with two or three applications of potassium phosphonate, new copper-hydroxide formulation or copper oxychloride used in a low doses of copper and alternative products like Myco-Sin-VIN® (clay with high aluminium content) in combination with Kendal® ( plant extract)

Untersuchungen des BÖL-Verbundprojektes zur Kupferminimierung im ökologischen Weinbau

The development of sustainable and economically feasible strategies to get an effec-tual control of downy mildew on grapes (Plasmopara viticola) with less than 3 kg/(ha*a) of copper to avoid further environmental risks is the intention of this project. Due to harmful effects on the natural environment, copper applications are under considera-tion. Therefore, in this four-year-project first of all test products are screened under greenhouse conditions on potted vines. Thereafter the best test agents are studied in organically managed test vineyards. Finally the selected strategies are tested under practical conditions on organically managed vineyards. Beyond these examinations a close link between wineries and research is given by SME and consultant partners. The results indicate that plant extracts, finely ground stones and new copper formula-tions could probably serve as plant resistance improvers and plant protection prod-ucts, respectively, to prevent attacks of P. viticola. Moreover, it was possible to select prosperous agents and strategies for the growing period 2007. These were agents of the substance categories “new copper formulations”, “plant extracts” and “finely ground stones”. Regarding the results of three growing periods, the project will provide effective and economically feasible alternatives for copper applications in order to deliver sustainable approaches for P. viticola control in practise

Strategien zur Regulation der Schwarzfäule (Guignardia bidwellii) im ökologischen Weinbau

Die Schwarzfäule tritt in einigen deutschen Weinbaugebieten flächendeckend auf und kann gravierende Ertragsausfälle verursachen. Um die Produktionssicherheit im ökologischen Weinbau zu gewährleisten, wurde ein Kooperationsprojekt mit der Zielsetzung initiiert, Informationen über die Biologie des Schadpilzes zu erarbeiten und Strategien zur Prävention und Bekämpfung der Krankheit unter den spezifischen Bedingungen des ökologischen Weinbaus zu entwickeln. Die Biologie des Schaderregers und seiner Interaktionen mit der Rebe wurde in Hinblick auf die Fruchtkörperentwicklung, die Sporenbildung und den Infektionsprozess eingehend untersucht und in Beziehung zu Witterungsbedingungen und Bewirtschaftungsparametern gesetzt. Die Ergebnisse bilden eine Grundlage für die Einschätzung des Infektionsrisikos und die Entwicklung von Entscheidungshilfen für den Rebschutz. Traditionelle und „pilzwiderstandsfähige“ Rebsorten wurden hinsichtlich ihrer Anfälligkeit für die Schwarzfäule charakterisiert, wodurch den Winzern Informationen für die Auswahl weniger Anfälliger Sorten zum Anbau in Befallsgebieten zur Verfügung stehen. Befallenes Rebholz und befallene Ranken wurden als bedeutende Quellen des Primärinokulums der Schwarzfäule identifiziert. Das Entfernen befallener Blätter bei Laubarbeiten erwies sich als Möglichkeit, das Infektionsrisiko für die Trauben zu reduzieren. Aus einer Vielzahl von Mikroorganismen, Pflanzenextrakten, Pflanzenschutz- und –stärkungsmitteln wurden wirksame Agenzien selektiert und im Freiland unter Praxisbedingungen geprüft. Die Kombination von Pflanzenschutzmitteln auf der Basis von Schwefel und Kupfer war besonders wirksam. Wurde, abhängig vom Entwicklungsstadium und dem Infektionsrisiko, das Kupfer mit Gesteinsmehl ersetzt, ließ sich der Kupferaufwand erheblich reduzieren. Im Gegensatz zu Gewächshausversuchen war die Wirkung saponinhaltiger Pflanzenextrakte im Freiland unzureichend. Bei entsprechender Formulierung zur Verbesserung der Regenfestigkeit könnte das große Potential dieser Pflanzenextrakte jedoch genutzt werden. Aufgrund der Ergebnisse des Forschungsprojekts stehen dem ökologischen Weinbau Informationen als Grundlage eines umfassenden Managementkonzepts für die Schwarzfäule zur Verfügung

Multi-annual comparisons demonstrate differences in the bunch rot susceptibility of nine Vitis vinifera L. 'Riesling' clones

Botrytis bunch rot is a major fungal disease of grapevines, and causes severe economic damage worldwide. Under humid climatic conditions, the development of bunch rot on grapes cannot be suppressed completely. Selection of planting material with lower bunch rot susceptibility represents one of the most efficient long-term tools in the complex bunch rot minimisation strategy. The present investigation conducted over four consecutive years (2013-2016) under the environmental conditions of the Moselle valley aimed at (i) detecting consistent differences in the bunch rot susceptibility within a group of nine commercially available Vitis vinifera L. 'White Riesling' clones, (ii) investigating potential underlying causes and (iii) deriving recommendations for 'Riesling' clone selection in practical viticulture. Disease severity and grape maturity (total soluble solids) progress could be well simulated by sigmoidal curves (R2 > 0.89; P < 0.038). On average of all four years, the dates when 5 % bunch rot disease severity were reached differed significantly by 9 days between the clone with the earliest epidemic (Trier 34) and the clone with the latest epidemic (Heinz 65). Multi-annual results enabled a classification of the nine clones according to (i) their relative bunch rot susceptibility as well as (ii) their relative precocity. Based on this, practical recommendations concerning a targeted clone selection as an integral long-term tool (i) in Integrated Pest Management contributing to pesticide reduction in viticulture as well as (ii) in the viticultural climate change adaptation strategy were derived

Tree islands enhance biodiversity and functioning in oil palm landscapes

In the United Nations Decade on Ecosystem Restoration1, large knowledge gaps persist on how to increase biodiversity and ecosystem functioning in cash crop-dominated tropical landscapes2. Here, we present findings from a large-scale, 5-year ecosystem restoration experiment in an oil palm landscape enriched with 52 tree islands, encompassing assessments of ten indicators of biodiversity and 19 indicators of ecosystem functioning. Overall, indicators of biodiversity and ecosystem functioning, as well as multidiversity and ecosystem multifunctionality, were higher in tree islands compared to conventionally managed oil palm. Larger tree islands led to larger gains in multidiversity through changes in vegetation structure. Furthermore, tree enrichment did not decrease landscape-scale oil palm yield. Our results demonstrate that enriching oil palm-dominated landscapes with tree islands is a promising ecological restoration strategy, yet should not replace the protection of remaining forests

Mechanical weeding enhances ecosystem multifunctionality and profit in industrial oil palm

A full factorial experiment in a state-owned industrial oil palm plantation in Indonesia evaluates whether reduced management via reduced fertilization rates and mechanical weeding can decrease the negative impacts on ecosystem functions and biodiversity while maintaining profitability of the plantation.Oil palm is the most productive oil crop, but its high productivity is associated with conventional management (that is, high fertilization rates and herbicide application), causing deleterious environmental impacts. Using a 2(2) factorial experiment, we assessed the effects of conventional vs reduced (equal to nutrients removed by fruit harvest) fertilization rates and herbicide vs mechanical weeding on ecosystem functions, biodiversity and profitability. Analysing across multiple ecosystem functions, mechanical weeding exhibited higher multifunctionality than herbicide treatment, although this effect was concealed when evaluating only for individual functions. Biodiversity was also enhanced, driven by 33% more plant species under mechanical weeding. Compared with conventional management, reduced fertilization and mechanical weeding increased profit by 12% and relative gross margin by 11% due to reductions in material costs, while attaining similar yields. Mechanical weeding with reduced, compensatory fertilization in mature oil palm plantations is a tenable management option for enhancing ecosystem multifunctionality and biodiversity and increasing profit, providing win-win situations