"Crazy Roots can't develop well in organic substrates"

Bacterium Agrabacterium rhizogenes, which causes Crazy Roots, develops less easily on organic substrates than on mineral substrates like stonewool. Therefore, the disease does not often occur on organic substrates. This was explained by Oliver Grunert during the meeting of Petracom last month.

The Growbags of Peltracom comprise a combination of peat and coco. The organic slabs becoming popular and are tested by several Dutch and Flemish growers. Besides the higher yield, the resistance against Crazy Roots is remarkable. “The chemical and physical characteristics of plants are substrates which are familiar to us. However, the resistance against Crazy Roots is new to us” says Stefaan Vandaele from Peltracom. Therefore, the company has investigated this issue. During the conference, the company presented the first results.

Ines van Marrewijk, Groen Agro Control

Crazy Roots

During the meeting Ines van Marrewijk from Groen Agro Contol explained more about Crazy Roots. Crazy Roots is a disease that many tomato growers in the Netherlands, are dealing with. Crazy Roots originates from the following bacterium: Agrobacterium rhizogenes. When infected, the growing process of the plant will become vegetative. Moreover, the bacterium is strong and is able to survive in water and soil. Therefore, the risk for recontamination is high. In order to minimize this risk, Ines Van Marrewijk from Groen Agro Control advises to disinfect water-related systems and to use plastic film on the floor.

Oliver Grunert

Microbial communities

Secondly, Oliver Grunert presented his study about microbial communities in substrates. In this study, the occurrence of Crazy Roots in organic and mineral substrate has been investigated. He conducted an experiment with aborigine plants. The experiment was divided into three categories: organic substrate with Crazy Roots, mineral substrate without symptoms of Crazy Roots and mineral substrate with Crazy Roots. No symptoms of Crazy Roots have been found in plants that grow on organic substrates. Grunert investigated the presence of bacteria on substrates. It was found that the DNA that the bacterium places on the plant, was not found on the plants that were grown on organic and mineral substrates with symptoms of Crazy Roots.

Peltraco growbags at Tomaholic in the Dutch city of Terneuzen. Click here to learn about their experiences.

Other bacteria

Grunert signals further relationships between the presence of the Agrobacterium rhizogenes and other bacteria. For example, a negative correlation can be found between the Saprobias C (Saprospiraceae) and the Agrobacterium rhizogenes. “The Saprobias C is able to destroy the slimy shaped molecules, that Agrobacterium rhizogenes produces. It destroys the environment in which the Agrobacterium rhizogene grows”, says Guntert. Based on the significantly different physico-chemsiche and biological properties between the different substrates can explain the resistance against Crazy Roots. The natural bacteria that are present make it difficult for the Agrobacterium rhizogenes to multiply and to infect the plant.

Watch the video about Growbags, made by Peltracom (in Dutch):

For more information:

Maaike Perneel
Peltracom n.v.
Skaldenstraat 7a
9042 Gent (BE)
Belgium
T: +32 (0)9 218 03 30
F: +32 (0)9 218 03 31
www.peltracom.be

Ines van Marrewijk
Groen Agro

Control
Distributieweg 1
2645 EG Delfgauw
the Netherlands
T: +31 (0)15-2572511
M: +31 (0)6-11347778
www.agrocontrol.nl