Biofungitsiidide mõju ristõieliste nuutri tõrjes
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Kuupäev
2021
Kättesaadav alates
02.09.2021
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Ristõieliste nuuter on majanduslikult oluline taimehaigus, mis kahjustab kõiki ristõielisi kultuure. Haigust põhjustav protist Plasmodiophora brassicae moodustab püsivaid ellujäämisstruktuure ning on mullas võimeline säilima pikki aastaid. Efektiivsed tõrjemeetodid on piiratud. Haiguse ennetamisel ja nakkuse vähendamisel võivad potentsiaalselt rolli mängida biofungitsiidid.
Käesoleva magistritöö eesmärk on hinnata kolme kaubanduslikult kättesaadava biofungitsiidi – Mycostopi, Prestopi ja Serenade ASO – mõju ristõieliste nuutri tõrjes. Laboritingimustes viidi 2020. aasta kevadel läbi potikatse patogeeniga nakatunud mullaga, mis koguti Viljandimaa tootmispõllult. Nii steriliseeritud kui ka steriliseerimata mulda töödeldi biofungitsiididega, kasutades kahte erinevat kulunormi. Mullaproovidest eraldati patogeeni DNA, millest määrati qPCR meetodiga patogeeni kontsentratsioon ja lisaks arvutati taimede haigusindeks.
Tulemuste analüüsil ilmnes, et Prestop vähendas oluliselt patogeeni kontsentratsiooni mittesteriilses loomuliku nakkusega mullas ühekordse tooteetiketil toodud soovitusliku kulunormi juures. Mycostopi ja Serenade ASO töötluste puhul P. brassicae hulk ei vähenenud. Siiski, taimejuurte haigusindeks vähenes Serenade ASOga töötlemise järgselt. Steriliseeritud põllumullas ei omanud ühegi preparaadi kasutamine statistiliselt olulist mõju.
Biofungitsiidide varieeruv efektiivsus võis tuleneda biofungitsiidides sisalduvate antagonistlike organismide erinevast toimemehhanismist, mulla madalast pH-st või kõrgest nakkuse tasemest töödeldavas mullas. Antud uurimistöö tulemuste põhjal võib järeldada, et biofungitsiid Prestop võiks olla kaasatud ristõieliste nuutri integreeritud tõrjesse. Täpsemate järelduste tegemiseks on vajalik läbi viia täiendavaid katseid biofungitsiidiga Prestop nii labori- kui ka põllutingimustes. Bioloogilise tõrje edasi arendamiseks võiks tulevikus isoleerida Eesti põllumuldadest kohaliku päritoluga antagonistlikke seene- või bakteritüvesid, mida katsetada P. brassicae tõrjeks.
Clubroot of crucifers is a root disease caused by the protist Plasmodiophora brassicae, responsible for causing significant economic damage to cruciferous crops. Clubroot is hard to manage since its resting spores are viable in soil for many years. Current methods to control P. brassicae are limited. Biological control methods are being increasingly investigated as a more viable alternative for controlling clubroot. The aim of this study was to assess the effect of commercially available biofungicides on the development of clubroot and its potential pathogen supressive activity. In this study, the biocontrol efficacy of biofungicides Mycostop, Prestop and Serenade ASO against P. brassicae were evaluated on oilseed rape in a laboratory experiment. Soil samples already infected with P. brassicae were collected from a commercial field in Viljandi County. A pot experiment with six different treatment variants and five replicates at each were established. The data collected partially supported the original hypothesis. Out of three biofungicides, Prestop was found to reduce P. brassica levels in infected soil by more than 90%. The efficacy of Mycostop and Serenade ASO in supressing P. brassicae was insignificant, although application of Serenade ASO reduced disease severity on plants. The efficacy of biofungicides may have varied due to the different mode of action of the antagonistic microorganisms. On the other hand, the effectiveness of biofungicides may also have been affected by the very high acidity of the soil, which favors disease development. Based on the results of this research, it can be concluded that the biofungicide Prestop could be used as part of an integrated disease management program for the control of clubroot. Further studies with the biofungicide Prestop are required under both laboratory and field conditions to determine its efficacy against clubroot.
Clubroot of crucifers is a root disease caused by the protist Plasmodiophora brassicae, responsible for causing significant economic damage to cruciferous crops. Clubroot is hard to manage since its resting spores are viable in soil for many years. Current methods to control P. brassicae are limited. Biological control methods are being increasingly investigated as a more viable alternative for controlling clubroot. The aim of this study was to assess the effect of commercially available biofungicides on the development of clubroot and its potential pathogen supressive activity. In this study, the biocontrol efficacy of biofungicides Mycostop, Prestop and Serenade ASO against P. brassicae were evaluated on oilseed rape in a laboratory experiment. Soil samples already infected with P. brassicae were collected from a commercial field in Viljandi County. A pot experiment with six different treatment variants and five replicates at each were established. The data collected partially supported the original hypothesis. Out of three biofungicides, Prestop was found to reduce P. brassica levels in infected soil by more than 90%. The efficacy of Mycostop and Serenade ASO in supressing P. brassicae was insignificant, although application of Serenade ASO reduced disease severity on plants. The efficacy of biofungicides may have varied due to the different mode of action of the antagonistic microorganisms. On the other hand, the effectiveness of biofungicides may also have been affected by the very high acidity of the soil, which favors disease development. Based on the results of this research, it can be concluded that the biofungicide Prestop could be used as part of an integrated disease management program for the control of clubroot. Further studies with the biofungicide Prestop are required under both laboratory and field conditions to determine its efficacy against clubroot.
Kirjeldus
Magistritöö
Aianduse õppekaval
Märksõnad
magistritööd, biotõrje, biofungitsiid, mullapatogeen, qPCR, ristõielised