SLU news

Combinatory IPM in Swedish potato production

Published: 28 May 2018

Potato is a crop with many serious diseases, for example potato blight, that require extensive and repeated treatments with pesticides in Swedish potato production. To find alternative pest management regimes, Åsa Lankinen has done a pilot project in potato with combinations of biological control agents and an inducing agent.

To be able to reduce the dependence of chemical treatment, development of alternative tools for plant disease control is necessary. Such tools include mechanical treatment, treatment with other organisms (biocontrol agents) or treatment with compounds that induce plant resistance to disease. However, field efficacies of these alternative tools are often not sufficient.

 A pilot project to look at alternative pest management in potato

Åsa Lankinen from the Department of Plant Protection Biology receive 150 000 SEK from The Centre for Biological Control, CBC, to lead a pilot project with colleagues at SLU. The aim was to investigate the combinatory effect of biological control and induced resistance agents, and see if these combinations could help improving the success and reliability of alternative pest management of potato blight, Phytophthora infestans, in potato.

Experiments were performed under controlled conditions in the greenhouse with detached leaf assays. Combinations with two biocontrol microorganisms, one bacterial agent (Bacillus amyloliquefaciens strain UCMB-5113) and one oomycete (Pythium oligandrum) were made as well as one inducing agent called BABA.

Bacillus and BABA treatment had an effect

– We found a trend that the combination of BABA and Bacillus had a dicreasing effect on development of potato blight, particularly for number of sporangia in the lesion. However, the difference was only significant between the combination and Bacillus alone, but not between the combination and BABA alone. A similar non-significant trend was seen for Pythium. Lesion size did not differ between any of the investigated treatments. This was probably a result of that lesions were generally very large, covering most of the leaves, says Åsa. 

– These experiments need to be repeated again in the greenhouse with both lower and higher spore content of the pathogen before we can draw any conclusions, or test these combinations in field trials. A PhD student is currently continuing these experiments, concludes Åsa.

Facts:

Phytophthora infestans is an oomycete or water mold, a microorganism which causes the serious potato disease known as late blight or potato blight.

Pythium oligandrum is an oomycete. It is a parasite of many fungi and other oomycetes including Botrytis, Fusarium and Phytophthora. It has been licensed as a biological control agent in the form of an oospore soil treatment, which reduces pathogen load and concomitant plant disease.

Bacillus amyloliquefaciens is a bacterium used in agriculture, aquaculture and hydroponics to fight root pathogens such as Rhizoctonia solani,and Fusarium bas well improve root tolerance to stress. It is considered a growth-promoting rhizobacteria and has the ability to quickly colonize roots.


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