The ability of plant resistance inducers to provide protection against viral diseases is one of their main advantages over conventional pesticides. In the case of viral diseases that cannot be controlled directly with pesticides, insecticides are used to control the vectors of viruses. However, the effectiveness of such treatments is strictly dependent on the time of application. The plant response to the application of systemic acquired resistance (SAR) inducers, as a result of the stimulating action of these substances, does not depend on the time of application as it triggers the plant’s natural defence mechanism. The best-recognised substance showing SAR inducer activity is acibenzolar-S-methyl ester (ASM, BTH). As its activity against different plant pathogens of crops has been well documented, the current research is concentrated on the search for novel substances of the type. The tested substance, N-methoxy-N-methylbenzo(1,2,3)thiadiazole-7-carboxamide (BTHWA), is an amide derivative of benzothiadiazole, showing plant resistance-inducing activity. This article presents the activity of BTHWA that has led to increased resistance of zucchini (Cucurbita pepo convar. giromontiina) towards viral infections. In addition, since the occurrence of the fungal pathogen, powdery mildew, was also observed during the two-year field experiments, the activity of BTHWA related to the reduction of infection with this fungus was also investigated. The substance was applied in two different variants either four or eight times, over the whole vegetation season. Surprisingly, the variant of four applications performed at the beginning of the vegetation season proved more effective in protection against viruses and fungus. A possible explanation may be the occurrence of the growth–immunity trade-off phenomenon that is known in the literature. Disturbance in plant metabolism resulting from eight applications may lead to lower yields of plants treated with SAR inducers. Perhaps such overstimulation of the plants we treated eight times may not have brought the optimum increase in plant resistance.

The effect of selected essential oils on rape pathogens such as Sclerotinia sclerotiorum, Phoma lingam, Rhizoctonia solani and Fusarium oxysporum was estimated in vitro studies. S. sclerotiorum showed the lowest susceptibility to the examined essential oil treatments. The thyme oil displayed the highest fungistatic effect and suppressed the culture growth of all tested fungal species when applied at the concentration of 0.2 and 0.02%. The lemongrass oil applied at the concentration of 0.2 and 0.02% inhibited the culture growth of the examined species from 90 to 100%. The tea tree and grapefruit essential oils applied and the concentration less than 0.2% showed poor effectiveness or no fungistatic effect on F. oxysporum and S. sclerotiorum. W warunkach in vitro określano wpływ wybranych olejków eterycznych na wzrost liniowy grzybów, którym przypisuje się cechy patogenów rzepaku: Sclerotinia sclerotiorum, Phoma lingam, Rhizoctonia solani i Fusarium oxysporum. Spośród badanych grzybów najmniej wrażliwy na aplikację olejków do pożywki okazał się gatunek Sclerotinia sclerotiorum. Najsilniejszymi właściwościami fungistatycznymi odznaczał się olejek tymiankowy. Jego obecność w podłożu w stężeniu 0,2 i 0,02% przyczyniła się do zahamowania w 100% wzrostu wszystkich testowanych grzybów. Olejek z trawy cytrynowej w stężeniu 0,2 i 0,02% hamował wzrost testowanych grzybów w zakresie od 90 do 100%. Najmniej skuteczne były olejki grejpfrutowy i z drzewa herbacianego, które nie wykazywały właściwości fungistatycznych wobec F. oxysporum i S. sclerotiorum w stężeniu poniżej 0,2%.

Active compounds used in agriculture are mainly in the form of acids. This applies primarily to substances that are inducers of systemic acquired resistance, which is one of the most promising methods of supporting plants in the fight against pathogens. The physicochemical properties and biological activity of such substances can be improved by derivatizing them to salt forms. We used the concept of ionic liquids to obtain novel compounds in the form of chlormequat ionic liquids. In this study we present synthesis and characterization of a series of novel ionic liquids composed of the chlormequat cation paired with plant resistance-inducing anions, including salicylic acid and its chlorinated derivatives, nicotinic acid and isonicotinic acid. The results indicate that the new compounds in the form of salts are characterized by better biological activity related to SAR induction and lower phytotoxicity compared to the parent compounds as their equivalents in acid forms. The obtained compounds demonstrated the ability to activate defense responses in tobacco and to reduce susceptibility to viral infection, highlighting their potential for further application in crop protection.

Grzyby są grupą organizmów bardzo zróżnicowaną i o ogromnym znaczeniu zarówno dla biosfery, jak i gospodarki. Stąd wynika potrzeba zabezpieczenia ich bioróżnorodności. Istnieje szereg metod laboratoryjnych zapewniających długotrwałe przechowywanie. Ich podstawowym zadaniem jest zapewnienie przeżywalności oraz zabezpieczenie cech biologicznych. Tradycyjne metody są proste, lecz pracochłonne, inne wymagają specjalistycznego sprzętu. Do najbardziej popularnych krioprezerwacyjnych metod należą: liofilizacja, mrożenie w glicerolu w –80°C i przechowywanie w ciekłym azocie. Obecnie za jedną z najlepszych metod przechowywania uznawana jest krioprezerwacja w ciekłym azocie, jednak nawet ona nie jest uniwersalna w stosunku do wszystkich izolatów. Fungi are extremly diverse and beneficial organisms both for environment and industry; thus we are obliged to secure it’s biodiversity. There are several laboratory methods for fungi longterm preservation. The main goal is to secure their vitality and biological properties. Some of them are simple but the same time laborious, other demand specific equipment. Among the most popular methods we find: freez-drying, cryopreservation at –80°C and in liquide nitrogen. The most reliable is cryopreservation in liquid nitrogen. However even this method is not universal and siutable for all cultures.