Effectiveness of fungicide-free approaches to the protection of potato and tomato against late blight

Abstract

The article describes fungicide-free ecologically tolerant technologies for the protection of potato and tomato against Phytophthora infestans (Mont.) de Bary, agent of late blight of these crops. It has been proved that potato cultivars with field resistance (Lugovskoy) provide a protection level comparable to the effectiveness of modern fungicides. Plant extracts from Southern plants can be used as biopesticides in order to additionally suppress the development of late blight. For example, extracts of four species from Yemen (fam. Asteraceae: Psiadia arabica Jaup and Spach; fam. Lamiaceae: Lawsonia inermis L ; Dodonea viscos L ; Euryops arabicus Steud. ex Jaub and Spach) were capable of suppressing late blight development on potato. On the contrary, plant growth regulators, Novosil (active compound triterpene acids), Larixin (active compound dihydroquerticin), and Terpenol (active compound triterpene acids), in spite of the periods of high efficiency against late blight, do not provide satisfying effect since these substances could sometimes even promote a pathogen development. Also, vaccination of tomato with attenuated strain of tobacco mosaic virus (TMV) could improve viability and immune status of plants under normal conditions, and in the case of stress situation it promoted weakness of plants and P. infestans infection. In Eastern Europe, fungicide-free technologies for the protection of potato and tomato against late blight, corresponding to the ecological criterion, should be additionally elaborated and tested for potato and tomato cropping.Opisane su ekoloski prihvatljive tehnologije, bez primene fungicida, za zastitu krompira i paradajza od Phytophthora infestans (Mont.) de Bary, agensa koji prouzrokuje plamenjacu ovih kultura. Potvrdjeno je da sorte krompira poseduju nivo otpornosti (Lugovskoy) koji se moze uporediti sa modernim fungicidima. Ekstrakti juznih biljaka se mogu upotrebiti kao biopesticidi kako bi se dodatno suzbio razvoj plamenjace. Na primer, ekstrakti cetiri vrste biljaka iz Jemena (porodica Asteraceae: Psiadia arabica Jaup i Spach; porodica Lamiaceae: Lawsonia inermis L; Dodonea viscos L; Euryops arabicus Steud. Jaub i Spach) su uspele da suzbiju razvoj plamenjace na krompiru. Nasuprot tome, regulatori rasta biljaka, Novosil (aktivno jedinjenje triterpenske kiseline), Larixin (aktivno jedinjenje dihidrokvercetin) i Terpenol (aktivno jedinjenje triterpenske kiseline), uprkos periodima visoke efikasnosti u sprecavanju plamenjace, ne daju zadovoljavajuci rezultat iz razloga sto ove supstance ponekad izazivaju razvoj patogena. Vakcinacijom paradajza duvanskim mozaicnim virusom moglo bi se poboljsati imunolosko stanje biljaka u normalnim uslovima, dok u stresnim uslovima biljke slabe i mogu da budu zarazene sa P. infestans. U istocnoj Evropi, tehnologije bez primene fungicida, koje se primenjuju za zastitu paradajza i krompira od plamenjace, a u skladu sa ekoloskim kriterijumima, trebalo bi dodatno prouciti i testirati na ovim kulturama.