Ertragseinbusse beim Anbau von Erbsen und anderen Leguminosen?

Leguminosen wie die Erbse verbessern die Bodenfruchtbarkeit. Sie sind daher eine wichtige Komponente im biologischen Anbau. Fehlende Resistenzen gegen bodenbürtige Erreger in modernen Sorten führen jedoch vermehrt zu Ertragseinbussen. Die Erreger überleben lange im Boden und können sich mit der Zeit anreichern. In Deutschland werden mittlerweile bei Erbsen Anbaupausen von bis zu 10 Jahren empfohlen. Damit es in der Schweiz erst gar nicht so weit kommt, beschäftigt sich das FiBL intensiv mit der «Leguminosenmüdigkeit ». Bereits liegen vielversprechende Forschungsergebnisse zu Resistenzen, Mischkulturen oder Kompost vor. Gesucht werden noch Landwirte, die unerklärliche Ertragseinbussen beim Anbau von Leguminosen, vor allem Erbsen, beobachten und daran interessiert sind, mit dem FiBL zusammenzuarbeiten. Dabei wird der betroffene Ackerboden allgemein untersucht (Bodenansprache, Spatenprobe, Fruchtfolge). Bei Verdacht auf Leguminosenmüdigkeit wird der Boden mittels FiBL-entwickelter Diagnosemethode auf Krankheiten untersucht

Resistant and susceptible pea lines harbour different root-rot pathogens and antagonistic fungi

Disease resistance encompasses the mechanisms that allow a plant to withstand or ward off a pathogen. The molecular responses of plants under pathogen attack and the underlying genetics have been extensively studied. However, resistance is not only a trait defined by the warfare between pathogen and host. In fact, resistance is an emergent phenotype of the interactions between the microbial community and the host. Fungal root diseases threaten pea (Pisum sativum L.) cultivation, and therefore a valuable protein source and important crop in low-input farming systems. Resistance in current pea varieties against multiple root pathogens is lacking. In order to acknowledge the rhizosphere microbiome as an integral part of the environment, 261 pea genotypes were screened for resistance on naturally infested field soil in a pot-based experiment. Thereof, eight lines with contrasting disease levels were selected and tested on four soils with different disease pressure in a follow-up pot experiment. Along root rot assessments, pea pathogens (F. solani, F. oxysporum, F. avenaceum, A. euteiches, P. ultimum and D. pinodella) and arbuscular mycorrhizal fungi were quantified in diseased roots using qPCR assays. The amount of fungal DNA detected in the roots differed among the pea genotypes and the four soils and a significant pea genotype x soil interaction was evidenced for several pathogen species. For example, the quantity of F. avenaceum in the roots mostly depends on the soil (two-way ANOVA, p < 0.01) and differs significantly between pea genotypes (p = 0.013). F. oxysporum and F. solani quantities showed significant pea genotype x soil interactions (p < 0.01 for both species). Significant correlations were found between F. avenaceum and F. solani quantity and root rot index (rs = 0.38, p < 0.01 and rs = 0.56, p < 0.01, respectively ). On the other hand, F. oxysporum quantity shows no relationship with root rot (rs = 0.007, p = 0.95). These results suggest differential roles of the microbes in the pea root rot and highlight the importance of incorporating the complexity of the soil microbiome at early stages of resistance screenings and breeding efforts. Resistance breeding against root rot will be challenged by the fact that soil microbes interact with each other and the plant and that their composition varies between different soils. Further insights into plant-microbe interactions and emerging molecular plant breeding tools will fuel future plant breeding

Ernährung sichern mit Mischkulturen

Um die Ernährung zu sichern braucht es neue Anbauformen. Dafür eignet sich der Mischanbau, denn er bietet ökologische und ökonomische Vorteile. Das FiBL optimiert durch Züchtung und Anbautechnik den Mischanbau im europaweiten Projekt ReMix

Wenn der Boden müde wird

Bei einem hohen Anteil an Leguminosen in der Fruchtfolge treten oftmals ein Ertragsrückgang bei Erbsen, Ackerbohnen und anderen Hülsenfrüchten auf. Man hat es mit der sogenannten Leguminosenmüdigkeit zu tun. Am FiBL wird geforscht, wie die Krankheit erkannt werden kann und welche Massnahmen dagegen helfen

Food security through mixed cropping

We need new farming systems to ensure food security. Intercropping promises to deliver environmental and economic benefits. In the European project ReMIX, FiBL is optimising mixed cropping systems through novel breeding and cultivation approaches

Breeding for mycorrhizal symbiosis: focus on disease resistance

Modern plant breeding can no longer afford to ignore the interaction between plants and microbial key players. Increasing evidence suggests (i) that the expression of many plant traits (such as nutrient use efficiency or tolerances against biotic and abiotic stresses) is mediated by beneficial microorganisms and (ii) that there is an exploitable genetic base for the regulation of symbiotic relationships. Arbuscular mycorrhizal fungi (AMF) play a key role in many of these trait expressions. While much is known about their ability to mobilise nutrients (especially phosphorus), the complex mechanisms of AMF-mediated disease resistance have only started to become apparent within the past decade. Besides competition for root space and resources, AMF also have the ability to induce plant defence mechanisms. Jasmonic acid (JA) and salicylic acid (SA) appear to be the key phytohormones that regulate relevant signalling pathways. The resulting activation of defence-related compounds can occur locally or systemically, constitutively or primed. Genotype-dependent plant reactions have been demonstrated for mycorrhizal responsiveness (when based on biomass), but not much is known when it comes to genotypic variation for AMF-mediated disease resistance. However, a few studies have provided first valuable insights. It is proposed to (i) include disease resistance as a factor to expand the term mycorrhizal responsiveness and (ii) make use of an indicator called “mycorrhiza use efficiency” as an additional measure to determine an optimum cost-benefit ratio of the mycorrhiza symbiosis. In order to detect differences in the efficiency, genotype selection needs to occur in environments that do not suppress the plant–microbe interaction. Thus, the value of organic breeding programmes is highlighted

Ein Pilz kommt selten allein

In einem Gramm Ackerboden stecken Tausende Bakterien- und Pilzarten sowie andere Kleinstlebewesen. Diese beachtliche Vielfalt macht den Boden zum artenreichsten Lebensraum der Erde. Besonders interessant für die Landwirtschaft ist der Mykorrhiza-Pilz

Cacao agroforestry systems do not increase pest and disease incidence compared with monocultures under good cultural management practices

Pests and diseases threaten cacao production worldwide. Agroforestry systems are traditionally seen by farmers as one of the causes of increased pest and disease incidence, in contrast with full-sun monocultures. Cultural management practices - e.g. regular tree pruning, frequent pod harvest, regular removal of infested pods, weed management - have been reported to be crucial for pest and disease management. We performed two experiments for the purpose of assessing the effect of (i) different cacao production systems, and (ii) the frequency of harvest and removal of infested pods on the incidence of pests and diseases and on the cacao yield. The first experiment was performed in a long-term system comparison trial in Bolivia, where data on pest and disease incidence were recorded for three years in five production systems: two monocultures and two agroforestry system under organic and conventional farming, and one successional agroforestry system, i.e. a high tree density multi-strata system. Pest and disease management did not differ between systems and relied on cultural management practices. Overall, the incidence of pests and diseases did not differ between production systems, which indicated they were not the driver of yield differences between them. Across production systems, only 14% of the pods were affected by pests and diseases; 70% of these were affected by frosty pod rot. More than 80% of the pods infected by frosty pod rot were removed before the sporulation phase. In the second experiment, the effects of the frequency of harvest and removal of infected pods - every 15 days versus every 25 days - on pest and disease incidence and yield were tested in four farmers’ fields. Fortnightly harvest and diseased pod removal significantly decreased disease incidence and increased cacao yield, by 25% and 46% respectively. Our results show that cacao agroforestry systems do not increase pest and disease incidence compared with monocultures when good cultural management practices are implemented, which, in turn, can increase the productivity of the cacao plantations

miCROPe 2019 – emerging research priorities towards microbe-assisted crop production

The miCROPe 2019 symposium, which took place from 2 to 5 December 2019 in Vienna, Austria, has unified researchers and industry from around the world to discuss opportunities, challenges and needs of microbe-assisted crop production. There is broad consensus that microorganisms—with their abilities to alleviate biotic and abiotic stresses and to improve plant nutrition—offer countless opportunities to enhance plant productivity and to ameliorate agricultural sustainability. However, microbe-assisted cultivation approaches face challenges that need to be addressed before a breakthrough of such technologies can be expected. Following up on the miCROPe symposium and a linked satellite workshop on breeding for beneficial plant–microbe interactions, we carved out research priorities towards successful implementation of microbiome knowledge for modern agriculture. These include (i) to solve context dependency for microbial inoculation approaches and (ii) to identify the genetic determinants to allow breeding for beneficial plant–microbiome interactions. With the combination of emerging third generation sequencing technologies and new causal research approaches, we now stand at the crossroad of utilising microbe-assisted crop production as a reliable and sustainable agronomic practice

Kommentar zu: Höhere Erträge bei gleichzeitigem Anbau verschiedener Kulturen

Der gleichzeitige Anbau verschiedener Kulturen auf demselben Feld bringt deutlich höhere Erträge pro Fläche bei bis zu einem Drittel geringerem Einsatz von Düngemitteln. Zu diesem Ergebnis kommt ein Autorenteam um Chunjie Li in einer globalen Metastudie. Sie sehen daher im sogenannten Intercropping eine Möglichkeit, auch intensive Landwirtschaft nachhaltiger zu gestalten. Der Anbau von Mischkulturen war über Jahrhunderte überall auf der Welt eine gängige Methode. In China spielt das Intercropping auch heute noch eine gewisse Rolle, die intensive Landwirtschaft in Europa und Nordamerika ist dagegen meist geprägt vom Anbau von Monokulturen. Die wachsende Weltbevölkerung, der damit steigende Nahrungsmittelbedarf und die häufig massiven Umweltauswirkungen der landwirtschaftlichen Praxis lassen auf der Suche nach effizienten und gleichzeitig nachhaltigen Anbaumethoden auch den Mischkultur-Anbau wieder interessant werden. Das Team um Chunjie Li hat in der Metastudie hunderte Datensätze berücksichtigt und ausgewertet. In diesen wurden insgesamt vier verschiedene Varianten des gemeinsamen Anbaus von zwei Kulturen auf einem Acker untersucht – wild durcheinander, wechselweise in Reihen, abwechselnd in Abschnitten und leicht versetzt in abwechselnden Abschnitten. Als besonders vorteilhaft zeigten sich dabei immer Anbausysteme, in denen Mais eine der beiden Kulturen war und die Saat und Ernte der beiden Kultur nicht zeitgleich stattfand. Durchschnittlich fanden die Wissenschaftler pro Hektar um 1.500 Kilogramm höhere Erträge als beim Anbau nur einer Kultur. Die Steigerung der Ausbeute in Kulturen mit Mais war dabei fast viermal so hoch im Vergleich zu Kulturen ohne Mais. In der Analyse wurde nicht der Wasserverbrauch beim Anbau berücksichtigt, der beim Intercropping aufgrund der längeren Wachstumsphase der Pflanzen meist höher ist als beim monokulturellen Anbau. Die Studie wurde im Fachjournal „Nature Plants“ publiziert