This review discusses the importance of glucosinolates in plant protection. The Brassicaceae, which are cultivated worldwide, use glucosinolates and their decomposition products to defend themselves against attacks by harmful organisms. The glucosinolate content varies among individual plant species, plant organs and developmental stages. The glucosinolate content in plants is also affected by biotic and abiotic factors, while the type or quantity of glucosinolate determines the susceptibility of the plants to insect pests. These facts can pose a problem when implementing this knowledge in cultivation of the Brassicaceae, especially in regions with moderate climates where Brassicaceae crops are exposed to attacks by a large number of harmful organisms. Under these circumstances, it is essential to research new, or to improve the existing environmentally acceptable methods of protecting Brassicaceae plants against economically important pests

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In a laboratory experiment, we studied the insecticidal effects of invasive alien plants on the rice weevil. The research was carried out in two parts. In the first part, we studied the insecticidal properties of seven different plant species, namely, Bohemian knotweed (Fallopia × bohemica), Japanese knotweed (Fallopia japonica), false indigo-bush (Amorpha fruticosa), tree of heaven (Ailanthus altissima), staghorn sumac (Rhus typhina), Canada goldenrod (Solidago canadensis), and giant goldenrod (Solidago gigantea). Mixtures of powders and wheat were prepared in two different concentrations, namely, 2.5 w% and 1.25 w%. The experiment was performed at temperatures 20 °C and 25 °C and at two humidity levels, 55% R.h. and 75% R.h. Very low mortality (below 8%) was found when using combinations with the higher relative humidity. No significant differences were observed between the effects of these concentrations. In the second part of the experiment, Norway spruce wood ash and diatomaceous earth (product SilicoSec®) were added to the powder obtained by milling leaves of four different invasive plant species (Canada goldenrod, staghorn sumac, tree of heaven, false indigo). In the independent application, wheat was added to the powder at a concentration 2.5 w%. In the treatments that involved mixtures of powder and wood ash/diatomaceous earth, we applied 1.25 w% plant powder and 1.25 w% wood ash or 1.25 w% plant powder and 450 ppm of a SilicoSec® preparation. The positive control was carried out as two separate treatments with 2.5 w% wood ash of Norway spruce and 900 ppm of the SilicoSec® product, while untreated wheat represented the negative control. The experiment was performed at two temperatures (20 °C and 25 °C) and two R.h. values (55 and 75% R.h.). The mortality of beetles was recorded on the 7th, 14th, and 21st day after the start of the experiment. Higher mortality rates of rice weevil adults were found at the higher relative humidity, and an important factor of mortality was also the day of exposure, as a higher mortality was found when the exposure of individuals to the tested substances was for a longer time period. After 21 days at 25 °C and 55% R.h., the combinations in which the lower concentration of Norway spruce wood ash was added to the powder of invasive alien plants achieved more than 90% mortality of beetles. By adding the plant powder of invasive alien plants to wood ash, we achieved a greater insecticidal efficacy of invasive plants and lower concentrations of wood ash. Nevertheless, the results of our research do not indicate any great usefulness of the plant powder of invasive plants in suppressing the rice weevil. Additional studies should primarily focus on the insecticidal efficacy of powder from the genus Solidago, which in our study, displayed the greatest insecticidal potential among the tested invasive plants.

From 2015-2016, different environmentally acceptable products for the control of harmful organisms, including the Colorado potato beetle (Leptinotarsa decemlineata), wireworms (Agriotes spp.), early blight (Alternaria solani) and late blight (Phytophthora infestans), were tested on potatoes. To control the Colorado potato beetle, was tested the efficacy of limestone dust at two concentrations, 345 and 690 kg ha -1 . Brassica pellets (200 g m -2 ) and calcium cyanamide (1000 kg ha -1 ) were tested against wireworms. Tincture of propolis and propolis glycolic extract (mentioned as propolis) at 5 and 10 ml 1 -1 H 2 O was tested against early and late blight. All of these products were combined into four treatments. Treatment 1 included treatments with limestone dust (690 kg ha -1 ), Brassica pellets and propolis (10 ml 1 -1 H 2 O). Treatment 2 included treatments with limestone dust (345 kg ha -1 ), calcium cyanamide (1000 kg ha -1 ) and propolis (5 ml 1 -1 H 2 O). Treatment 3 was positive control -use of registered phytopharmaceutical plant protection method, and treatment 4 was negative control (untreated plots). The inspection of all developmental stages: egg clusters, first and second instar larvae after hatching (L1-L2), and third and fourth instar larvae after hatching (L3-L4, adults), of the Colorado potato beetle was performed. After harvest, the tuber yield was evaluated. The evaluation of the yield was conducted on the small, medium and large tubers. The amount of damage caused by wireworms on the potato tubers was also detected in the different tubers. Calcium cyanamide was more effective than Brassica pellets against wireworms, whereas at a dose of 10 ml 1 -1 H 2 O, propolis was proven to be a good alternative for the management of early and late blight under unfavourable weather conditions for an epidemic outbreak. In 2016, the potato tuber yield in all three treatments was significantly higher than that in the untreated plots.With the combination of the tested products, promising alternative control strategies for future potato production systems might be obtained, which will be suitable for farming under changing climate conditions with a very narrow spectrum of registered phytopharmaceutical plant protection products.

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