The synthetic method of dithianon intermediate 2,3-dichloro-1,4-naphthoquinone was introduced. Starting with raw material sodium 4-amino1-naphthalene sulfonate, 2,3-dichloro-1,4-naphthoquinone was synthesized through ...The synthetic method of dithianon intermediate 2,3-dichloro-1,4-naphthoquinone was introduced. Starting with raw material sodium 4-amino1-naphthalene sulfonate, 2,3-dichloro-1,4-naphthoquinone was synthesized through acidification, chlorination and oxidation. After filtration and recrystallization, more than 98% of 2,3-dichloro-1,4-naphthoquinone was obtained, and the yield reached 76%(measured by sodium 4-amino-1-naphthalene sulfonate).展开更多
Dithianon is a multi-site fungicide and has never been object of suspects and reports of reduced sensitivity and activity. Italian IFP technicians had the suspect of reductions of activity by this fungicide on </sp...Dithianon is a multi-site fungicide and has never been object of suspects and reports of reduced sensitivity and activity. Italian IFP technicians had the suspect of reductions of activity by this fungicide on </span><i><span style="font-family:Verdana;">Venturia inaequalis.</span></i><span style="font-family:Verdana;"> Methodologies, </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> were carried out to verify this suspect. Populations poorly controlled with suspects on dithianon and sensible ones </span><span><span style="font-family:Verdana;">were utilized. The tests </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> permitted to evidence light and non-significant</span></span><span style="font-family:Verdana;"> reductions of sensitivity of poorly controlled populations </span></span><span style="font-family:Verdana;">with </span><span style="font-family:Verdana;">respect </span><span style="font-family:Verdana;">to </span><span style="font-family:""><span style="font-family:Verdana;">sensible ones. </span><i><span style="font-family:Verdana;">In vivo tests</span></i><span style="font-family:Verdana;"> on seedlings were non</span></span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;">reliable for a general low activity of dithianon. On the contrary, the original </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> methodology on grafted apple plants showed several reductions of activity, with moderate levels and a spot distribution in orchards. The cause was probably due to the increase</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> treatments with dithianon caused by problems on other groups of fungicides and by a high infective pressure in some years. It is discussed if this reduction can be considered a resistance phenomenon or a temporary modification of the interactions </span><span style="font-family:Verdana;">of </span><span style="font-family:Verdana;">plant-fungus-fungicide.展开更多
文摘The synthetic method of dithianon intermediate 2,3-dichloro-1,4-naphthoquinone was introduced. Starting with raw material sodium 4-amino1-naphthalene sulfonate, 2,3-dichloro-1,4-naphthoquinone was synthesized through acidification, chlorination and oxidation. After filtration and recrystallization, more than 98% of 2,3-dichloro-1,4-naphthoquinone was obtained, and the yield reached 76%(measured by sodium 4-amino-1-naphthalene sulfonate).
文摘Dithianon is a multi-site fungicide and has never been object of suspects and reports of reduced sensitivity and activity. Italian IFP technicians had the suspect of reductions of activity by this fungicide on </span><i><span style="font-family:Verdana;">Venturia inaequalis.</span></i><span style="font-family:Verdana;"> Methodologies, </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> were carried out to verify this suspect. Populations poorly controlled with suspects on dithianon and sensible ones </span><span><span style="font-family:Verdana;">were utilized. The tests </span><i><span style="font-family:Verdana;">in vitro</span></i><span style="font-family:Verdana;"> permitted to evidence light and non-significant</span></span><span style="font-family:Verdana;"> reductions of sensitivity of poorly controlled populations </span></span><span style="font-family:Verdana;">with </span><span style="font-family:Verdana;">respect </span><span style="font-family:Verdana;">to </span><span style="font-family:""><span style="font-family:Verdana;">sensible ones. </span><i><span style="font-family:Verdana;">In vivo tests</span></i><span style="font-family:Verdana;"> on seedlings were non</span></span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;">reliable for a general low activity of dithianon. On the contrary, the original </span><i><span style="font-family:Verdana;">in vivo</span></i><span style="font-family:Verdana;"> methodology on grafted apple plants showed several reductions of activity, with moderate levels and a spot distribution in orchards. The cause was probably due to the increase</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> treatments with dithianon caused by problems on other groups of fungicides and by a high infective pressure in some years. It is discussed if this reduction can be considered a resistance phenomenon or a temporary modification of the interactions </span><span style="font-family:Verdana;">of </span><span style="font-family:Verdana;">plant-fungus-fungicide.