Case Study 12

Case Study 12. Control of phytopathogenic fungi via direct identification and the influence of pesticides use on communities of soil fauna in organic and conventional potatoes cropping systems. Nemoral (Estonia).

Which problem will be solved: For targeted IPM implementation the causal agents of the disease including air- and soil-borne phytopathogenic fungi must be identified fast and accurately. It is well documented that many phytopathogenic fungi for instance Puccinia spp., Botrytis spp., Fusarium spp., Phytium spp. etc. may spread long distances through wind dispersal of spores and cause outbreaks far from the source location and also remain viable in soil for several growing seasons. Targeted disease management with reduced input of pesticides should rely on monitoring the phytopathogenic fungi present in the region.

State of the art: In order to deal with the problem of fungal pest occurrence the higher input of pesticides are used (conventional farming, no-till farming) and high tillage intensity (conventional and organic farming), which reduce functional soil biodiversity. Farmers are advised to follow the crop rotation with cover crops and grains. Following potato, cover crops are sown then cultivated grains are contaminated with mycotoxins. In no-till farming system on the soil is formed litter layer, that is accumulation point for pesticides from where those are released into soil. For economic reasons, the rotation sequence is 2-3 years. In the long-term, soil conditions are threatened and soil biodiversity lost.

Objective: The objective of this case study is (i) to assess the amount and types of spores that are spread by air (ii) to monitore both organic and conventional farming systems in order to provide farmers with region specific data in to adjust the use (sequence, norms, types) of pecticides which have impact on soil fauna communities in potato and grains cropping systems (iii) to find out pesticides accumulation rate for no-till fields and impact to soil fauna.

Proposed management practices: It is aimed through monitoring system to set up more precise management practices for targeted pesticide application and promote in wider sense the soil fauna in conventional and organic farming. The management practices to be tested in cooperation with farmers including changes in soil management and pesticide application.

Progress with the case study in relation with the state of the art: Pest management decision making should rely on precise information collected about phytopathogenic fungal species (including invasive fungal species) present in the environment. The measures of current study will help to reduce the external input, through sustainable agricultural management and substantial improvement of soil fauna services for fungal plant pest control. In the results, agroecosystems are more resilient and managed with less monetary costs; while with higher soil biodiversity the yield reductions are avoided and healthier crops are obtained.

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