Preliminary Studies on Development of a New Environmentally Friendly Plant Protection Product Against Grey Mould

The development of new environmentally friendly plant protection products against grey mould disease (caused by Botrytis cinerea Pers.) was started in 2010. In the Latvian State Forest Research Institute “Silava”, production of coniferous biomass extracts using different solvents for extraction was performed. During 2010-2011, several laboratory investigations were carried out in the Institute of Biology, University of Latvia. Effectiveness of pine (Pinus sylvestris) and spruce (Picea abies) biomass extracts against Botrytis cinerea was tested. On the basis of coniferous extracts, 11 formulations were created and characterised. The effect of the formulations on mycelial growth of B. cinerea test cultures was tested using the fungal radial growth test. All formulations had inhibitory effect on mycelium growth (inhibition rate over 50%) at concentration 20 g L in medium. The impact of formulations on plants after spraying was evaluated using in vitro propagated strawberry plants. Chlorophyll content and chlorophyll fluorescence were estimated. Extracts did not show negative effect on the chlorophyll content and fluorescence of strawberry leaves. Field investigations on strawberry (Fragaria × ananassa Duch.) ‘Senga Sengana’ and primocane raspberry (Rubus idaeus) ‘Gerakl’ were conducted in the Pûre Horticultural Research Centre in 2011. None of tested the coniferous biomass extract formulations showed higher effectiveness than fungicide Signum® (pyraclostrobin 6.7%+ boscalid 26.7%, BASF). Jauna, videi draudzīga augu aizsardzības līdzekļa izstrāde pret pelēko puvi tika uzsākta 2010. gadā. Latvijas valsts Mežzinātnes Institūtā ’’Silava” iegūti un raksturoti četri kokaugu biomasas ekstrakti. Laikā no 2010. gada līdz 2011. gadam Latvijas Universitātes Bioloģijas institūtā veikti laboratorijas izmēģinājumi, lai noteiktu dažādu priedes (Pinus sylvestris) un egles (Picea abies) biomasas ekstraktu efektivitāti pret Botrytis cinerea. Uz skujkoku ekstraktu bāzes izveidotas un raksturotas 11 dažādas preparatīvās formas. Preparatīvo formu efektivitāte pārbaudīta, izmantojot sēņu radiālās augšanas testu, lai noskaidrotu to ietekmi uz B. cinerea izolātu micēlija augšanu. Visas preparatīvās formas, pievienojot barotnei 20 g L koncentrācijā, samazināja micēlija augšanu (samazinājums vairāk kā 50%). Tika arī vērtēta preparatīvo formu ietekme uz augiem pēc smidzināšanas, izmantojot in vitro pavairotos stādus. Noteikts hlorofila saturs un fluores- cence. Ekstrakti būtiski neiete