Phytopathology
“We keep a real zoo of pest insects”
Phytopathology is a growing and highly dynamic field of research. Kerstin Krüger took over as Group Lead at KWS in March 2021. In this interview, she reports on why knowledge of apids, viruses and the like is so important and what role phytopathology plays in the development of plant varieties.
Bans of chemical plant protection products, climate change, and globalization are bringing back many types of “old” plant diseases and pests or require new approaches to secure yields in a more sustainable manner. Kerstin Krüger works to respond to these challenges with an active attitude and an energetic team of scientists and assistants to tackle important diseases and pests of all KWS crops.
How did you get into phytopathology?
Phytopathology combines my two interests – plant science and insects. Insects are fascinating because of their amazing diversity. They are fundamental to the functioning of our ecosystems, but some species threaten crops, either by consuming the plants directly or by vectoring pathogens.
I spent the past 30 years in South Africa, where I still train young scientists as an Extraordinary Professor at the University of Pretoria. I have been leading research in applied entomology and agriculture, focussing on non-chemical management of insect vectors of plant diseases.
What was the main reason for you to make the shift from university research to your current role at KWS?
I am passionate about science and bridging the gap between academia and the agricultural sector. I have worked very closely with growers in the past in projects related to plant diseases. My fascination with this position is the opportunity to have a more direct impact by taking the research into the field. At KWS, I get to develop phytopathology to address the current sustainability and climate challenges, making use of modern technological advances and providing innovative solutions.
Kerstin Krüger started as Phytopathology Group Lead at KWS in March 2021. She returned to Germany from the University of Pretoria in South Africa and looks forward to bridging the gap between academia and industry.
Why does a plant breeding company need a phytopathology department?
Malaria is a well-known example of an insect-transmitted human disease. Plants have plenty of these as well; for example, the virus yellows disease of sugarbeet is caused by different plant viruses transmitted by aphids feeding on the plant sap. Diseases can also be transmitted by other organisms; the beet necrotic yellow vein virus that causes Rhizomania in sugarbeet is transmitted by a soil-borne fungus.
Our group’s main expertise includes mycology, nematology, entomology, and plant protection. We interact with nearly all KWS departments to support breeders, product development and strategic portfolio decisions. Our tasks cover routine services, such as disease diagnostics, screening of new breeding material, disease and pest monitoring, and crop protection in greenhouses and the field. Further core activities include the development and establishment of new tests and methods. We also consult globally in phytopathological questions across KWS.
Our responsibilities have increased considerably over the past years due to growing disease and pest pressure and to the EU’s sustainability goals of halving the use and risk of chemical plant protection by 2030. We already number 10 technicians and four scientists and are expanding further to meet current and future demands.
What is your normal workflow to detect and diagnose problems related to pests or disease?
Our workflow usually starts with initial observations in the field, often made by the grower. For example, fungal diseases that have previously been suppressed by chemicals, or first plants that are no longer resistant to pests or diseases, can be detected this way. The closeness of KWS to growers makes it possible for us to react at an early stage.
We cultivate the different pathogens and keep a real “zoo” of insect vectors and pest insects – we really are culturing the enemies of almost all KWS crops! These are used to monitor or test plants for resistance by infecting or infesting plants that are grown either in the greenhouse or in the field and scored according to their susceptibility.
Our work is still very much hands-on. However, plans for digitalizing plant scoring are underway, which is very exciting.
The phytopathology team members cover various areas of expertise. Britta Ahlswede and Florian Grotis are scoring sugarbeet plants infected with the fungus Cercospora beticola.
Birthe Prüser-Schwingel inspects sunflower seedlings for sunflower rust resistance.
At which locations is phytopathology carried out?
Our central department is based in Einbeck and much of our experimental work is done here. However, it is always best to deal with localized diseases and pests in their original environment. For example, in the case of a pest in Chile, we may support the South American station by transferring our know-how to set up cultures, produce protocols, and support the testing and analysis of results. For more global problems, the tests can be run at different field sites in parallel.
What cooperations are there with other companies or universities?
We have various ongoing collaborations in different parts of the world. In the case of new diseases or unknown insect vectors, we collaborate with research institutions for basic research.
Fusarium isolation for species monitoring. Plant infection with Fusarium species is problematic due to the production of mycotoxins that may affect humans or animals.
Peach potato aphid Myzus persicae is a main transmitter of sugarbeet yellowing viruses. Aphids carrying different types of yellowing viruses are used to test the tolerance of sugarbeet varieties.
Root harvest for Rhizomania (beet necrotic yellow vein virus (BNYVV); Wurzelbärtigkeit) testing. The virus is transmitted by a soil-borne fungus.
KWS is committed to sustainable agricultural practices. What contribution does phytopathology make?
Due to the ban of some chemical plant protection products, such as the neonicotinoids, many diseases and pests are becoming a problem again. Chemicals need to be replaced with resistant varieties and biological control where possible. In addition, the changing climate brings new stresses to plants; for example, we are seeing increasing population sizes or range expansions of some pests. In addition, globalization means that plant diseases and pests are being transported to new regions.
We have to be prepared for these new challenges, and our approach is to be proactive. Our ultimate aim is to play an integral role in the development of products that enable growers to operate in a sustainable and profitable way.
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