scholarly journals Obstacles and ways of forming effective protection of rice crops from weeds

2021 ◽  
pp. 25-30
Author(s):  
L. Tsilinko
Keyword(s):  
Vegetative Reproduction ◽  
Weed Species ◽  
Weed Plants ◽  
Subsequent Conversion ◽  
Working Solution ◽  
High Yields ◽  
Systematic Control ◽  
Total Stock ◽  
Working Liquid

Goal. Assessment of the current level of soil contamination in rice checks with weed seeds and determination of the reasons for insufficient efficiency of herbicide application to ensure high yields of rice sown in the south of our country. Research methodology: Field small-site experiments were conducted in crops (rice checks) of the Institute of Rice of NAAS of Ukraine (Antonivka village, Skadovsk district, Kherson region). The size of the sown experimental plot is 66 m2, the accounting area is 50 m2. The experiments were repeated 4 times. Placement of plots is regular in two tiers. Accounting and analysis were performed in accordance with the specifics of the requirements «Methods of testing and application of pesticides» edited by Professor S.O. Tribel, and Methods of research in beet growing. The level of yield of rice crops was determined by continuous harvesting of accounting plots on all repetitions of variants by a special selection combine «Sampo-2000» with the subsequent conversion into t/ha. Results. Washing of soil samples from rice checks and analysis of washed seeds and organs of vegetative reproduction revealed that the largest stocks of live seeds are present in the horizon 0—10 cm, and average 1310.0 pieces/ m2 of rooster millet. The total stock of seeds of different types of weeds that retained the ability to germinate in the soil was 12987.8 pieces/ m2. The number of weed seedlings in weed control crops (option 1) averaged 894.8 pcs/m2. In crops of option 2 after application of soil herbicide Kommand 48, KE (Clomazon, 480 g/l) with a concentration of working solution — 0.25%, at the rate of consumption of 0.5 l/ha before germination, the number of weed germs decreased to 550.5 pcs/ha or by 38.5%. Spraying of crops of rice of sowing in the period of formation — 3 leaves with a norm of expenses of working liquid of 200 l/hectare, herbicide Topshot, 113 OD of m.d. normal sow 3.0 l/ha with a concentration of working solution — 1.5%, further reduced the number of weeds in crops. The overall decrease in the number of weed plants in rice crops averaged 90.2%. Seedlings of acute plague died by 91.0%, rooster millet by 97.1%, bitter gourd by 96.3%. At the same time, the seedlings of Korsakov’s monochoria died out by 79.4% of the compact reed tuber by 77.1%, and the spreading plague by 76.2%. In crops of sown rice, 59.5 pcs/ m2 of weed plants of different species still remained to grow. Surviving plants were formed in rice crops on average 1452 g/m2 weight or 39.5% of its maximum volume in the experiments (option 1). The main part of the mass of weed plants was monocotyledonous species — 73.9%. The yield of rice crops was 5.12 t/ha or 44.8% of the maximum in the experiments (option 3). Conclusions: Systems of measures to protect rice crops should be aimed primarily at reliable and systematic control of seedlings and seedlings of the most numerous and problematic weed species: members of the botanical families Osokov and Tonkonogov.

INFLUENCE OF DICARBOXYLIC ACIDS ON SOWING QUALITY OF SPRING BARLEY

1970 ◽  
pp. 22-25
Author(s):  
N. N. Loy ◽  
S. N. Gulina
Keyword(s):  
Organic Acids ◽  
Spring Barley ◽  
Dose Range ◽  
Dicarboxylic Acids ◽  
Rotary Machine ◽  
Working Solution ◽  
Negative Effect ◽  
Sprouted Seeds

The effect of presowing seed treatment on various concentrations of dicarboxylic (organic) acids on the sowing characteristics of spring barley has been studied. Seeds were treated with organic acids obtained by exposing cuttings to the radiation with a dose of 100 kGy and consequent hydrolysis, in concentrations: 1•10-7 %; 1•10-9; 1•10-11; 1•10-13 and 1•10-15 % on a laboratory rotary machine RVO-64 for one day before laying for germination. Distilled water was used for the control case. The rate of application of the working solution calculated as 10 liters / ton of seeds. Seeds were germinated in filter paper rolls in accordance with GOST 12038-84 requirements. The temperature was maintained at +24 ° C in the thermostat where the glasses with rolls were placed. For determination of germinative power and laboratory germination the sprouted seeds were evaluated after three and seven days, respectively. In laboratory experiments it was established that the treatment of barley seeds of varieties Zazersky 85, Nur and Vladimir with organic acids (OK) in different concentrations had both a stimulating and a negative effect. On the Zazersky 85 variety, in variants with acid concentrations of 1•10-9 and 1•10-11, an increase in germination energy (EP) by 2-4% and a significant decrease (by 3-4%) of laboratory germination (LV) of barley seeds were noted. On the Nur variety, the increase in EP was observed at 4% (concentration 1•10-11), LV and seed growth force (CPC) by 2-7% at a concentration of 1•10-7 and in the dose range 1•10-11 - 1•10-14 compared to the control values. On the grade of Vladimir, an increase in EP, LV, and CPC was found to increase by 1-6% at concentrations OK 1•10-7 and 1•10-13. It was shown that the treatment of seeds with acids led to an increase in the length of the germ in all studied varieties (by 3-9%) and dry biomass of 7-day-old seedlings - by 3-6%. Consequently, the treatment of seeds with a mixture of dicarboxylic acids has a stimulating effect on the sowing quality of spring barley.

scholarly journals New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectroscopic Analysis ◽  
Palladium Complexes ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Enantiomerically Pure ◽  
One Step ◽  
Uv Visible ◽  
High Yields

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.

Determination of Cardinal Temperatures of Flax-leaf Alyssum (Alyssum linifolium) in Response to Salinity, pH, and Drought Stress

Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 470-476 ◽  
Author(s):  
Ahmadreza Mobli ◽  
Ali Ghanbari ◽  
Mehdi Rastgoo
Keyword(s):  
Germination Rate ◽  
Farming Systems ◽  
Quadratic Polynomial ◽  
Polynomial Model ◽  
Weed Species ◽  
Wide Range ◽  
Species Specific ◽  
Cardinal Temperatures ◽  
Different Levels

AbstractFlax-leaf alyssum (Alyssum linifoliumSteph. ex. Willd.) is a winter weed species in irrigated and dryland farming systems of Iran. Experiments were conducted to compare the cardinal temperatures ofA. linifoliumat different levels of drought, salt concentration, and pH. In all experiments, the dent-like model showed a better fit than the quadratic polynomial model.Alyssum linifoliumproduced the highest germination rates at pH 7 and a temperature of 20C in nonstress treatment. Minimum, optimum, and ceiling temperatures in the dent-like model were 4.1 (upper=26.8, lower=10.0) and 35C, and in the quadratic polynomial model were 3.3, 19.1, and 35.0C, respectively. At increased salinity and drought potential levels, the minimum temperature increased, while optimum and ceiling temperatures decreased. Seeds could germinate at up to 20 dS m−1and −1 MPa, respectively, but germination rate and percentage significantly decreased. The seeds of this weed germinated across a wide range of pH values (4≤pH≥8), but the temperature range at which seeds could germinate was reduced. These data serve as guidelines for species-specific propagation protocols and agricultural decision support systems.

scholarly journals 1,3,4-Thiadiazole-Containing Azo Dyes: Synthesis, Spectroscopic Properties and Molecular Structure

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2822
Author(s):  
Agnieszka Kudelko ◽  
Monika Olesiejuk ◽  
Marcin Luczynski ◽  
Marcin Swiatkowski ◽  
Tomasz Sieranski ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Spectroscopic Properties ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Chemical Structures ◽  
Vis Spectroscopy ◽  
High Yields

Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, N,N-dimethylaniline and phenol were synthesized in high yields by a conventional diazotization-coupling sequence. The chemical structures of the prepared compounds were confirmed by 1H-NMR, 13C-NMR, IR, UV-Vis spectroscopy, mass spectrometry and elemental analysis. In addition, the X-ray single crystal structure of a representative azo dye was presented. For explicit determination of the influence of a substituent on radiation absorption in UV-Vis range, time-dependent density functional theory calculations were performed.

A Method for Assessing Herbicide Performance in Small Plot Experiments

Weed Science ◽  
1977 ◽  
Vol 25 (5) ◽  
pp. 386-389 ◽  
Author(s):  
A.S. Hamill ◽  
P.B. Marriage ◽  
G. Friesen
Keyword(s):  
Individual Species ◽  
Weed Species ◽  
Rating Systems ◽  
Small Areas ◽  
Retrieval Systems ◽  
Weed Cover ◽  
Weed Plants ◽  
Plot Area ◽  
Small Plot ◽  
Grass Weed

A method is described that provides an accurate and useful assessment of herbicide performance in small plot experiments. This method is an extension of previous rating systems and provides an assessment of the control of individual species through an estimation of the percentage that each contributes to the total broadleaf or grass weed cover on the whole plot area. It permits data collection on individual weed species but is less time-consuming than counting individual plants and it takes into account the size and vigor of individual weed plants as well as their relative abundance. Further, the system allows tabulation of data from across the entire plot rather than from small areas within the plot. The data can be readily entered into various computerized retrieval systems.

scholarly journals Copper(I)-Catalyzed Click Chemistry as a Tool for the Functionalization of Nanomaterials and the Preparation of Electrochemical (Bio)Sensors

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2379 ◽  
Author(s):  
P. Yáñez-Sedeño ◽  
A. González-Cortés ◽  
S. Campuzano ◽  
J. M. Pingarrón
Keyword(s):  
Electrochemical Sensors ◽  
Functional Integration ◽  
Future Directions ◽  
Physiological Conditions ◽  
Electrode Surfaces ◽  
Wide Range ◽  
High Yields ◽  
By Products ◽  
Powerful Strategy

Proper functionalization of electrode surfaces and/or nanomaterials plays a crucial role in the preparation of electrochemical (bio)sensors and their resulting performance. In this context, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has been demonstrated to be a powerful strategy due to the high yields achieved, absence of by-products and moderate conditions required both in aqueous medium and under physiological conditions. This particular chemistry offers great potential to functionalize a wide variety of electrode surfaces, nanomaterials, metallophthalocyanines (MPcs) and polymers, thus providing electrochemical platforms with improved electrocatalytic ability and allowing the stable, reproducible and functional integration of a wide range of nanomaterials and/or different biomolecules (enzymes, antibodies, nucleic acids and peptides). Considering the rapid progress in the field, and the potential of this technology, this review paper outlines the unique features imparted by this particular reaction in the development of electrochemical sensors through the discussion of representative examples of the methods mainly reported over the last five years. Special attention has been paid to electrochemical (bio)sensors prepared using nanomaterials and applied to the determination of relevant analytes at different molecular levels. Current challenges and future directions in this field are also briefly pointed out.

scholarly journals Molecular identification and chromosomal localization of new powdery mildew resistance gene Pm11 in oat

2019 ◽  
Vol 133 (1) ◽  
pp. 179-185
Author(s):  
Tomasz Ociepa ◽  
Sylwia Okoń ◽  
Aleksandra Nucia ◽  
Justyna Leśniowska-Nowak ◽  
Edyta Paczos-Grzęda ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Gene ◽  
Powdery Mildew Resistance ◽  
Chromosomal Localization ◽  
Powdery Mildew Resistance Gene ◽  
Consensus Map ◽  
Avena Sterilis ◽  
Subsequent Conversion ◽  
Selection Of

Abstract The appropriate selection of various traits in valuable plants is very important for modern plant breeding. Effective resistance to fungal diseases, such as powdery mildew, is an example of such a trait in oats. Marker-assisted selection is an important tool that reduces the time and cost of selection. The aims of the present study were the identification of dominant DArTseq markers associated with a new resistance gene, annotated as Pm11 and derived from Avena sterilis genotype CN113536, and the subsequent conversion of these markers into a PCR-based assay. Among the obtained 30,620 silicoDArT markers, 202 markers were highly associated with resistance in the analysed population. Of these, 71 were selected for potential conversion: 42 specific to resistant and 29 to susceptible individuals. Finally, 40 silicoDArT markers were suitable for primer design. From this pool, five markers, 3 for resistant and 2 for susceptible plants, were selected for product amplification in the expected groups. The developed method, based on 2 selection markers, provides certain identification of resistant and susceptible homozygotes. Also, the use of these markers allowed the determination of heterozygotes in the analysed population. Selected silicoDArT markers were also used for chromosomal localization of new resistance genes. Five out of 71 segregating silicoDArT markers for the Pm11 gene were found on the available consensus genetic map of oat. Five markers were placed on linkage groups corresponding to Mrg12 on the Avena sativa consensus map.

The competitive and yielding ability of some sub-tropical pasture species sown alone and in mixtures under intermittent grazing at Samford, south-eastern Queensland

1969 ◽  
Vol 9 (37) ◽  
pp. 181 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite
Keyword(s):  
White Clover ◽  
Competitive Ability ◽  
Grazing Management ◽  
Tropical Pasture ◽  
Weed Species ◽  
Rhodes Grass ◽  
Nitrogen Levels ◽  
Tropical Legumes ◽  
High Yields ◽  
Low Nitrogen

Eleven introduced tropical grasses were compared in single grass swards and nine of these were compared in mixtures containing two or three grasses. The pastures received 300 lb nitrogen an acre a year as urea and were grazed five times a year. A basal legume mixture of tropical legumes and white clover sown with the grasses failed to persist. There were large differences between the grasses in competitive ability and this varied with time. Samford Rhodes grass, Nandi setaria, and Pangola were the most aggressive, and the Paspalum species-P. plicatulum P. dilatum and P. commersonii the least aggressive. Hyparrhenia hirta, which had done well at low nitrogen levels, failed to compete with weed grasses at the higher nitrogen level used in this study. Rhyncheytrum repens and commercial Rhodes grass were the dominant weed grasses in the establishment year. These rapidly decreased with time, and Digitaria didacola-blue couch, became the dominant weed species. Plots containing Nandi setaria, Samford Rhodes grass, or Pangola, gave the highest yields, and plots containing P. dilatatum the lowest. There was no yield advantage in combining grasses in mixtures-the mixture giving similar or lower yields than the best grass in the mixture grown alone. Under a period of farm grazing the three Rhodes grasses used declined sharply and the proportion of blue couch increased. The high yields from plots dominated by blue couch indicate that, agronomically, this has been a neglected naturalized species. Only Nandi setaria and Pangola were able to compete effectively with blue couch under the 'farm grazing' management imposed.

The possibilities of polarography in the chemistry of nitroazoles

1984 ◽  
Vol 49 (6) ◽  
pp. 1342-1353 ◽  
Author(s):  
Dragica Dumanović ◽  
Janka Ćirić ◽  
Djuro Kosanović ◽  
Dragoslav Jeremić
Keyword(s):  
Nitro Group ◽  
Systematic Investigation ◽  
Nitro Compounds ◽  
The Other ◽  
Polarographic Method ◽  
Spectrophotometric Methods ◽  
Group Position ◽  
High Yields

Based on systematic investigation of mononitroimidazoles, selective polarographic and spectrophotometric methods for determination of nitrazole compounds in reaction mixture are proposed. It was proved that the selectivity is based on the different properties of the nitro group due to the effects of the nitro group position in the ring, the type and position of the other substituents and on the fact whether the compound is N-substituted or not. The proposed methods can be successfully used for monitoring the synthetic procedures and decreasing the number of experiments for optimization. Based on the anticipated and proved behaviour of the nitro compounds of pyrazole, novel mononitropyrazole derivatives were synthetized in a new way and with high yields. Applying the polarographic method it was discovered that during N-substitution of tautomeric mononitroimidazole and mononitropyrazole substrates other byproducts were obtained besides the main products and undesired isomers. The products were identified and then a correct and more complete N-substitution scheme could be given. Following quantitatively these N-substitution processes conclusions which directly concern the mechanism of reactions were drawn.

scholarly journals A database of weed plants in the European part of Russia

2020 ◽  
Vol 8 ◽  
Author(s):  
Alyona Tretyakova ◽  
Nickolay Grudanov ◽  
Pavel Kondratkov ◽  
Olga Baranova ◽  
Natalya Luneva ◽  
...  
Keyword(s):  
Species Diversity ◽  
Crop Protection ◽  
European Part ◽  
Perennial Grasses ◽  
Weed Species ◽  
Row Crops ◽  
Factors Affecting ◽  
Weed Plants ◽  
European Part Of Russia ◽  
Winter Crops

Weeds are plants that, although not specially cultivated, grow and often adapt to growing in arable lands. They form an ecological variant of flora, as a historically-formed set of species growing on cultivated soils. For the rational use of the chemical and biological crop protection products and to produce safe and high-quality food, up-to-date data on the floristic diversity of weeds and the patterns of its geographical change are required. The need for a weeds' database arises that allows many specialists to work together independently. However, the great value of any database lies not in its existence, but in the accumulation of data that can be used to analyse the factors affecting the species diversity of weeds. A dataset of weed species diversity and their distribution in the European part of Russia, based on the results of the authors' own research from 1999 to 2019, has been created. The dataset includes 24,284 observations of occurrences of weed plants, which were obtained on the basis of 2,049 relevés of segetal plant communities in seven regions of the European part of Russia. In total, the dataset includes information about 329 species of vascular plants growing in 65 farmlands: cereals, spring and winter crops, industrial crops, row crops and perennial grasses (Tretyakova et al. 2020).

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