The investigations carried out in the Institute of Industrial Organic Chemistry on sulphur fungicides are discussed and some neu investigation possibilities are presented. Elementary sulphur - one of the oldest known fungicide is still being used in plant protection, mostly against powdery mildews in orchard, vegetables, ornamental and cereal crops. Because it is of low toxicity to mammals and aqueous organisms, and does not disturbance the environment it is now respected as one of the "ecological fungicide". In contrasts to the modern, highly selective, systemic fungicides sulphur does not provoke the resistance building in plant pathogenic fungi, what is profitable in its usage as component of fungicidal mixtures.
Обсуждается - главным образом на основании литературы - зависимость между химической структурой и биологической активностью соединений из группы триазолей применяемых в качестве фунгицидов в сельском хозяйстве. По мере возможности учитывали различия в активности изомеров отдельных соединений. Соедиения были разделены в рабочей порядке на четыре подгруппы: производные триадимефона, дикло- бутразола, пропиконазола, флютриафоль и сродственные соединения. В указанных подгруппах пытались оценить влияние заменителей на биологическую активность, особенно фунгицидную. Обсуждаются мнения касающиеся возможности иммунизации грибов к фунгицидам триазоловой группы в лабораторных и полевых условиях.
EN
The relationship between the chemical structure and biological activity of preparations of the triazolic group applied in agriculture as fungicides is discussed mainly basing on the literature data. Differences in the activity of izomeres of particular compounds were taken, as far as possible, into consideration. The compounds were divided in the working scale into four subgroups: derivatives of triadimephon, of diclobutrazole, of propiconazole, flutriazol and homologous subgroups. One tried to estimate in these subgroups the effect of substitutes on biological, and particularly fungicidal activity. Opinions concerning possibility of immunization of fungi against triazolic fungicides under laboratory and field conditions are considered.
The synthesis methods of some new compounds from the group of the acrylonitrile methylothio derivatives were described, especially the synthesis of 2-methylothio-2-amine-1-cyanoacrylonitrile. The main substrate for the synthesis was malononitrile. They demonstrate fungicidal activity against five fungi. They possessed however also negative properties: mammal toxicicity and high allergenic activity.