Emerging Strategies for the Bioremediation of the Phenylurea Herbicide Diuron

Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.

Use of Biopreparations in the Cultivation of Raspberry Using Organic Technology

В современных условиях популяризации производства сельскохозяйственной продукции по органическим стандартам актуальными являются исследования установления эффективности агротехнических приёмов таких технологий на продуктивность и качество продукции растениеводства, в том числе малины красной, имеющей ведущее значение среди ягодных культур региона. В 2020 году в однофакторном полевом опыте на площади 288 кв. м на дерновой среднесуглинистой почве в условиях производства одной из сельскохозяйственных организаций Ярославской области были изучены различные биопрепараты (Байкал ЭМ-1, Органик-агро, Оргавит) как элементы органической технологии возделывания ремонтантной малины сорта Поклон Казакову с точки зрения их влияния на конкурентоспособность культуры по отношению к сорным растениям, качество и продуктивность ягод малины. Было установлено, что применение биопрепаратов Органик-агро и Оргавит на ремонтантной малине способствует повышению её конкурентной способности по отношению к сорным растениям – наблюдалась тенденция снижения численности многолетних сорных растений в среднем на 12,5%, малолетних сорных растений было меньше на 23,1% при использовании препарата Оргавит, а при внесении Органик-Агро представители этой биогруппы отсутствовали. Использование биопрепаратов способствовало динамике улучшения качественных показателей продукции малины (количество сухого вещества имело тенденцию увеличения в среднем на 0,04 процентных пунктов, количество сахаров увеличилось на 0,43 п.п., титруемая кислотность – на 0,09 п.п., содержание аскорбиновой кислоты – на 9,6%). Количественные показатели продуктивности малины также возросли, особенно при использовании препарата Оргавит – прибавка урожая составила 12,4% по сравнению с контролем. In modern conditions of popularization of agricultural products production according to organic standards, researches are relevant to establish the effectiveness of cultural practices of such technologies for the productivity and quality of crop production, including red raspberries which are of leading importance among berry crops in the region. In 2020 in a single-factor field test on an area of 288 square meters on soddy middle loamy soil under the conditions of production of one of the agricultural organizations of the Yaroslavl region, various biopreparations (Baikal EM-1, Organic-agro, Orgavit) were studied as elements of the organic technology for cultivating everbearing raspberry of the Poklon Kazakov variety in terms of their impact on the competitive ability of the crop in relation to weed plants, the quality and productivity of raspberries. It was found that the use of biopreparations Organic-agro and Orgavit on everbearing raspberry contributes to increasing its competitive ability towards weed plants – there was a tendency to reduce the number of perennial weeds by an average of 12.5%, small weed plants were less by 23.1% when using the preparation Orgavit, and when applying Organic-Agro representatives of this biogroup were absent. The use of biopreparations contributed to the dynamics of improving the quality indicators of raspberry production (the amount of dry matter tended to increase by an average of 0.04 percentage points, the amount of sugars increased by 0.43 percentage points, base-titratable acidity – by 0.09 percentage points, the content of ascorbic acid – by 9.6%). Quantitative indicators of raspberry productivity also increased, especially when using the preparation Orgavit – the yield increase was 12.4% compared to the control.

Weed Spread and Caraway (Carum carvi L.) Crop Productivity in a Multi-Cropping System

The field experiment was carried out at the Experimental Station of Vytautas Magnus University Agriculture Academy (Lithuania) in 2017–2019. The aim of the study was to determine and to compare weed spread and caraway crop productivity in sole (spring barley, spring wheat, pea, caraway), binary (spring barley-caraway, spring wheat-caraway, pea-caraway) and trinary (spring barley-caraway-white clover, spring wheat-caraway-white clover, pea-caraway-white clover) crops. In the second and the third years of caraway cultivation, it was estimated that the abundance of perennial weeds in the crops increased. In the first year, significantly the highest dry matter mass of weeds was determined in non-sprayed with herbicides binary crops with undersown caraway and in trinary crops with undersown caraway and clover; in the second year—in the caraway binary crops, when they were grown after barley and wheat without clover; in the third year—in caraway binary and trinary crops when they were grown after barley, wheat and pea without clover and after barley and wheat with clover. In the second year, the highest yields of caraway seeds were obtained by growing them in peas, and in the third year by growing them in wheat together with clover. Caraway can be grown in trinary crops, including white clover, and harvested in the second or the third year of the vegetative season.

Potato protection system with preparations of the company “Agrorus & Co.”

The results of tests of the potato protection system with chemical preparations of the company “Agrorus & Co” in the conditions of the Moscow region on Favorit and Sante varieties are presented. The results of the tests showed that the use of herbicides reduced the number of perennial weeds by 87,3% and annual weeds by 91,4 %. The prevalence of alternariasis on the date of the last accounting relative to the control (78,8%) decreased by 1,7 times, and the degree of development by 2,7 times, late blight – on the susceptible variety of the tops of Santa almost twice, and the degree of development by 3,4 times. The biological effectiveness against the Colorado beetle of preparations for pre-planting treatment was 96,9-100,0%, and for preparations during the growing season – 99,5-100,0%. The increase in gross and commercial yield on the Favorite variety was 56,3% and 58,2%, respectively, on the Santa variety – 31,4% and 32,8% compared to the control.

Effects Of Sideration On The Number Of Weeds Used At Different Times

In keeping up and expanding soil fertility by applying siderite (green manure), increasing the yield of cotton by planting and cultivating pisum, pea, rapeseed, and grain as siderite crops from selected plants; amid cultivation, 39-51 tons of green biomass per hectare was collected in summer and 17-22 tons in autumn, and their effect on weed numbers were determined. In this case, in the experimental field, more perennial weeds were found, such as salomalaykum (Cyperus rotundus L.), field bindweed (Convolvulus arvensis L.), ajrik (Cynodon dactylon (L.) Pers.), and annuals were found in semizoot (Portulaca oleracea L.), white sorghum (Chenopodium album L.), common rosemary (Amaranthus retleflexus L.), ituzum (Solanum nigrum) and others were observed. As a result, the number of yearly and perennial weeds beneath the influence of summer sideration diminished by 2.4-2.6 units compared to the control option before the 1st cultivation between cotton rows, and by 4.6-4.7 units before the final irrigation, or under the influence of autumn sideration. In accordance with the over, a decrease of 2.8-3.1 units was accomplished, and before the final irrigation - to 5.0 units. The most noteworthy reduction in weeds was observed in rapeseed and barley variants utilized as siderates in both experiments.

Effectiveness of successful application of herbicides ‘Chemical Glyphosate’ and ‘Himstop’ 330 against annual and perennial weeds in cotton fields of Uzbekistan

This article provides information on the effectiveness of successive application of herbicides chemical glyphosate (CG) (3 l/ha) and Himstop 330 (1.5 l/ha) against annual and perennial weeds in cotton fields. When Himstop 330 was used at a rate of 1.5 l/ha, the number of annual weeds was reduced by 84.6-90.4%. 14.5-17.9%. When CG 54% herbicide was applied at a rate of 3.0 l/ha, annuals were reduced by 16.5–19.4%, while perennials were reduced by 86.4–91.5%.CG, when applied in the fall at a rate of 3.0 l/ha, and Himstop 330, at a rate of 1.5 l/ha (in series) with the sowing of annual weeds 89.6-94.5%, perennials 88.2- Provides a loss of 92.6%.When CG was used separately at a rate of 3.0 l/ha and Himstop 330 at a rate of 1.5 l/ha, 3.25 q/ha more cotton was obtained than the control variant. CG (3.0 l/ha) and Himstop 330 (1.5 l/ha) herbicides when applied in series provide a high cotton yield of 5.2 q/ha per hectare.

Effects of continuous application of Samurai and Zellek Super herbicides on cotton fields against weeds in the conditions of Uzbekistan

This scientific article provides data on the effectiveness of successive application of herbicides against annual and perennial weeds in cotton fields on arable lands plowed with simple and two-sided plows. When the herbicide Samurai (1.5 l/ha) is applied separately, the annual weeds are effectively lost (86.8-90.2%), and have a weak effect on perennials. When Zellek Super (1.0 l/ha) herbicide is used separately, it has a weak effect on annuals (24.0-32.0%), effectively reducing weeds. Both perennial weeds (90.5-93.0%) and perennial weeds are effective when applied in series with Samurai (1.5 l/ha) and Zellek Super (1.0 l/ha) herbicides 88.9 -93.3% loss. Cotton yield will increase by 1.8-5.4 q/ha compared to the control option. Consecutive application of Samurai (1.5 l/ha) and Samurai (1.5 l/ha) and Zellek Super (1.0 l/ha) herbicides against annual and perennial weeds is recommended.