Most people are acquainted with microorganisms. Most also have an acquaintance with gardens. On the other hand, horticulture as a discipline and a factor for food supply has a somewhat more anonymous presence in the public conscientiousness. Horticulture is defined as the science and art of growing, processing and marketing fruit, berries, wine, vegetables, nuts, mushrooms, herbs and medicinal plants, as well as ornamental plants. In contrast to other agricultural industries, horticulture is characterised by putting the plant or culture at the centre, as well as by a high input of production factors and a high output of products of high quality, mainly for the consumpton of perishables.
Production takes place outdoors or under glass or in tunnels. This implies a high degree of specialisation, which, in turn, requires a lot of resources. Owing to the production factors and productivity, the impact of production on the environment and the effect of the environment on cultivation and the product are highly sensitive factors with regard to both the working and cultural environment and the environment at a large scale.
Biological control
One example is the way in which strategies for biologically controlling plant pathogens are developed. Several projects at the researcher training school relate to this subject, by finding strategies for biocontrol of grey mould and powder mildew in organic production and for environmentally friendly cultivation systems in integrated and organic production of tomatoes in greenhouses. But biological control of potato blight is also studied.
Reduction of carbon dioxide emissions resulting from horticultural production necessitates technical innovations for energy use in greenhouses. In this context, heating and lighting systems have an important role. However, in these complex systems, changes to one factor affect the interaction between all factors. For example, certain types of low energy lighting give rise to changes in plant climate, to lower leaf temperatures and high humidity. This has effects on microorganisms that colonise leaf surfaces, irrespective of whether they are neutral, antagonistic or pathogenic. In regard to the growing of ornamental plants, where cosmetic deviations are not tolerated by either the trade or the consumers, this is of great importance. These aspects are examined within the framework of a doctoral thesis that is associated with the recently funded Interreg project Green Growing.
Environmental aspects are of importance not only for present production of horticultural products. Today, 80 per cent of the population are already living in towns and they are responsible for around 75 per cent of resource use. The food producers of tomorrow must pay attention to this. “Grey” areas in urban environments that are unused at present will be used in both small scale and large scale “industrial” production. In some of these contexts also, microorganisms can be employed to safeguard a good environment.
Gastric and intestinal diseases
In recent years, outbreaks of gastric and intestinal diseases could be traced to fruit and vegetables. It is especially fruit and vegetables that are consumed raw or after minimum cleansing which are most at risk. Intestinal infections can be spread during the entire horticultural production process, both before and after harvest. Mistakes made in an earlier stage of production cannot always be rectified at a later stage. Salmonella, verotoxin-producing E. coli, Campylobacter, Yersinia or winter vomiting disease and Cryptosporidium are some of the infectious diseases which have attracted attention in these contexts. Formerly, these intestinal infections were mainly related to animal products. The outbreak in Germany in May 2011 that was traced to sprouts was a warning sign. These outbreaks demonstrated not only an uncommon aggressiveness but also the significance of the international ramifications of horticultural production networks which demand traceability both backwards and forwards in the entire network.
In spite of the fact that the vegetable eating public did not become aware of the serious consequences of an outbreak, primary producers in Sweden have been fighting the problem ever since the Swedish EHEC outbreak in Halland which was traced to iceberg lettuce. Research inputs concerning these and similar outbreaks have also been dealt with in a doctoral thesis associated with the researcher training school µHORT which had a particular focus on the hygiene of irrigation water. Internalisation of intestinal infections in fruit and vegetables will be an aspect of a doctoral thesis within the framework of a recently funded project within the cross-disciplinary food research programme Tvärlivs.
The researcher training school µHORT. This school at Alnarp is a Swedish-German collaboration. The photograph shows the course on a study visit to the largest tomato grower in Sweden. All visitors must wear protective clothing. Photographer: Beatrix Alsanius
µHORT
The goal of the researcher training school µHORT is to strengthen research and researcher training in horticulture/market gardening through a greater degree of expertise, increased knowledge and know-how on a broader abstract level and in interaction with closely associated fields. It provides an infrastructure through postgraduate courses, research seminars, conferences and workshops. In the beginning, six course packages were offered, three basic ones in order to integrate doctoral students from different disciplines and to create an awareness of the subject’s complexity and to create a methodological basis, and two advanced packages in some specialist areas. In order to prepare the students for an existence outside academia after their disputation and to reinforce understanding of the issues and approaches in related business, there are also facilities for individual industrial projects which have so far been embarked upon by three of the participants.
The researcher training school µHORT has stimulated researcher training and horticultural research both in and out of Sweden. Thanks to the funding by Formas, the involved doctoral students have been able to orientate themselves within the disciplines involved, broadened their outlooks and have also received a platform for continued development as researchers after the award of their doctorates. The most recent doctoral course, situated at Geisenheim, Germany, which for obvious reasons attracted many German visiting lecturers, gave the doctoral students an excellent opportunity to come into contact with the different research environments. In addition to this, the researcher training school is also a stimulus for the associated environments, their junior and senior researchers, and has worked to make contacts inside and outside the school.
µHORT - the researcher training school in Alnarp
The researcher training school µHORT - or microbial horticulture – started in the autumn of 2008 with the support of Formas as a collaborative venture between several departments at SLU, the Department of Food Hygiene at Lund University and the Department of Phytomedicine at Campus Geisenheim in Germany. This holistic arena promotes interactivity between horticulture, plant pathology, microbiology and molecular biology, as well as food technology and biotechnology. The theme of the researcher training school is based on microbial interactions within the horticultural production network, from “farm to intestine”. The theme of a recently terminated course package is Microbial pathogens and biocontrol in a changing climate: a horticultural perspective, and the next package is called Recycling, bioremediation and system analysis.
At the meeting point between basic and applied disciplines, the researcher training school µHORT highlights the horticultural potential for securing and influencing environmental, food safety and life quality aspects. At present, 16 doctoral students are working at the school. A new batch of doctoral students await admission.
In order to keep abreast of the rapid development in DNA based methods, an in-depth course, situated at the Julius Kühn Institute in Braunschweig, Germany, has also been started. Apart from this, the researcher training school has also been engaged in a mentoring programme which has recently finished. The first international symposium on microbial horticulture was held at SLU in Alnarp in May 2011; a follow-up is planned for June 2013 in Holland, and there are plans for a workshop in February 2012 in Quebec, Canada.
Author
:
Beatrix Alsanius
is Professor of Horticulture, with the focus on production systems, at Swedish University of Agricultural Sciences SLU in Alnarp