Search Results (7)

The use of plant protection products (PPPs) is the main method of controlling Cercospora leaf spot (CLS), as it constitutes a cheap and effective approach that is easy for farmers to follow. Unfortunately, it is widely recognized that the use of PPPs poses a risk not only to the environment but also to human health. The urgent need for sustainable development, recommended by the European Union and expressed in the “Farm to Fork Strategy”, includes a serious restriction on the use of PPPs. This strategy assumes a 50% reduction in the use of PPPs by 2030. These efforts have driven the exploration of innovative and effective plant protection strategies utilizing new active compounds. The examined substance, N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), is a novel amide derivative of benzothiadiazole with the ability to induce systemic acquired resistance (SAR). This work presents a series of experiments conducted in the process of determining the appropriate technology for BTHWA use and proving its effectiveness in controlling CLS in sugar beet cultivation. It has been demonstrated that the application of treatments using BTHWA or BTHWA combined with a fungicide in a reduced number of treatments had the same effect on the reduction of plant infection with C. beticola and obtained root and technological sugar yields the same as those that resulted from the use of a full fungicidal treatment. The results provide grounds for reducing the use of fungicides by showing that the same effects can be attained by combining or replacing them with BTHWA. Full article

The aim of this study was to examine lettuce using different concentrations of the biostimulator N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), a new benzothiadiazole derivative. Different concentrations of BTHWA during watering and spraying were applied to lettuce. Chlorophyll fluorescence, gas exchange, thermal images, and plant parameter data were used to study physiological process and the growth of lettuce. Chlorophyll fluorescence data showed a strong effect after the first BTHWA application to lettuce. After three applications, the plants were harvested and data were recorded. Similarly, in the second experiment, gas exchange and thermal images were recorded after the first treatment of BTHWA. Our findings showed improved chlorophyll efficiency after the first BTHWA application, and no adverse effects were recorded on the overall photochemistry at any concentration. Regarding growth parameters, spraying BTHWA reduced the fresh weight but decreased the damage index. A lower watering concentration (0.066 mg/L) applied three times did not cause any damage to plants and fresh weight, even after repeated applications. Infrared thermal images showed BTHWA application also significantly affected plant temperature. Gas exchange data revealed that sprayed plants exhibited higher transpiration rates, stomatal conductance, and photosynthetic rates when compared to watered and control plants. This study suggests that application of a low dose of BTHWA is safe to use in agriculture practices in lettuce without compromising its growth and yield. Full article

The use of inducers of systemic acquired resistance (SAR) is widely described in the literature. Such substances have important advantages over plant protection products (PPPs) and, thus, are often indicated as their alternatives. The main risk indicated in the context of the widespread use of SAR inducers is that of yield reduction that may result from the excessive metabolic imbalance of the treated plant. The general aim of the study presented was to check the effect of using a new active substance, namely N-methoxy-N-methylbenzo(1.2.3)thiadiazole-7-carboxamide (BTHWA), on tulips cultivated in greenhouse conditions. The plant response to BTHWA treatment was also analyzed in terms of the extent to which the growth–immunity phenomena would occur. Surprisingly, the application of BTHWA provided not only efficient protection against fusariosis but also resulted in the stimulation of the growth and development of tomato plants. The results proved very interesting as they stand in contrast to other results on SAR induction. The method of BTHWA application used in this study resulted in SAR induction at a level sufficient to provide effective protection and, at the same time, did not cause disruption to plant metabolism that would result in yield reduction. Full article

Oak powdery mildew caused by Erysiphe alphitoides (Griffon and Maubl.; U. Braun & S. Takam.) is a common disease in European forests. One of the most susceptible species is the pedunculate oak (Quercus robur L.). Presently, a few methods are available to control powdery mildew, e.g., the use of fungicides (e.g., based on citric acid), antagonistic fungi or bacteria, chemical treatments (e.g., sulphur, potassium bicarbonate) or genetic resistance. In our study, we aimed to check the effects of using chitosan derivatives and novel active substances inducing the plants’ natural resistance: benzodiathiadiazole (both in neutral and salt form). 84 pedunculate oak seedlings were subjected to the experiment in three treatment variants (plus positive and negative controls). The plants were treated with active substances and inoculated with E. alphitoides. Although the powdery mildew symptoms appeared in all variants, they were manifested mainly by the mycelium in the form of small spots. The experiment indicated that the highest limitation of powdery mildew mycelium was achieved by applying N-methyl-N-methoxyamide-7-carboxybenzo(1,2,3)thiadiazole (BTHWA). The application of BTHWA reduced disease development by 88.9% when compared to the effects of the other variants. Full article

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. Full article

Ash tree disease is caused by an ascomycete fungus Hymenoscyphus fraxineus, which first emerged in 1992, eastern Poland. Site factors, genetic predispositions, and resistance to the pathogen have not been fully described yet. The general aim of the study undertaken was to check the effect of using a new active substance representing benzothiadiazoles, a BTH derivative, namely, N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), on ash saplings. A total of 41 ash saplings, aged three to five years, were subjected to this experiment in six variants of treatment. The results of the inoculation with H. fraxineus indicated that the treatment with BTHWA resulted in the limitation of the size of necrotic phloem lesions. Although the lesions were detectable in the cross section, the plants showed no visible signs of infection. The results suggest that H. fraxineus development in ash saplings can be slowed down or even completely stopped through triggering plant resistance by BTHWA. Full article

Triggering the plant resistance induction phenomenon by chemical compounds, for example acibenzolar-S-methyl ester, has been known and described in scientific literature. Other benzothadiazole derivatives have been also described; however, their properties have not been sufficiently studied. The tested substance, N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), is an amide derivative of benzothiadiazole, showing a stimulating effect on plant growth, apart from its plant resistance inducing activity. This article presents the impact of BTHWA, used solo and in the program with fungicides, on the strawberry plants development, fruits health, yield, and quality parameters of the crop. The results show that the combined use of BTHWA and fungicides had a positive impact on the plants health and fruit health and nutraceutical and nutritional composition of compounds when compared to the results obtained when strawberries were treated only with the BTHWA or the fungicide. As a result of BTHWA use, the partitioning of assimilates has changed, which directly translated into the results of the conducted experiments. A reduction in the respiration of the fruit during storage was also observed, possibly due to a reduced disease infestation and a lower dry matter content in the fruit. A correlation between the parameters determined during the experiment was found. The BTHWA mode of action was evidenced to be beneficial to strawberry plants and fruit. Full article