AGRIS - 

2023

João Victor dos Santos Caldas | Alessandro Guerra da Silva | Guilherme Braga Pereira Braz | Sergio de Oliveira Procópio | Itamar Rosa Teixeira | Matheus de Freitas Souza | Laís Tereza Rêgo Torquato Reginaldo

One factor limiting the achievement of high yields in the soybean crop is weed interference. The level of weed interference can vary according to the specificities of the weed community but also due to the agronomic characteristics of the soybean varieties. The objective of this work was to evaluate the effects of weed interference on soybean varieties of different relative maturity groups (RMG). A field experiment was implemented in a randomized complete block design, in a 3 × 4 factorial scheme, with five replications. The treatments were composed of the varieties BMX Flecha<sup></sup> (RMG 6.6), BMX Power<sup></sup> (RMG 7.3), and BMX Bônus<sup></sup> (RMG 7.9), associated with the following four weed managements: weeding throughout the cycle; weeded up to 20 days after emergence (DAE); weeded after 20 DAE until the end of soybean cycle; not weeded throughout the entire cycle. There was no interaction between the effects of the varieties and the weed management for emergence speed index, plant height, chlorophyll, first pod height insertion, plant population, thousand-grain weight and yield. The initial weed management caused changes in the composition of the weed community. The managements weeded throughout the cycle and weeded up until 20 DAE provided higher levels of chlorophyll and grain yield. The management without weeding during the entire cycle negatively influenced yield components. Late interventions in weed control, regardless of the soybean variety, result in yield losses.

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Directory of Open Access Journals - Sweden

2023

Dionisi, Mathilde | Aubertot, Jean-Noel | Sester, Mathilde | Département Environnements et Sociétés

Context: Intensive use of pesticides in rice paddies is harmful to both human health and biodiversity. As ricefarmers tend to overuse pesticides, especially in the tropics, the use of decision support tools is one way forpesticide reduction. Various models have been developed to simulate the development of rice pests, or the impactof pests on the rice crop.Objective or research question: The objective of the review is to identify modeling approaches that may be usefulfor agroecological protection of rice crops against a wide range of pests, but not to provide an exhaustive reviewof models. We analyzed the scientific literature on rice pest, crop models integrating pest levels, and rice croppestmodels according to the number and type of pests simulated, the structure of the model, whether croppingpractices are included in the simulation, the consideration of pest damages and yield losses, and hence the actualuse of these models to improve crop protection strategy.Methods: We analyzed a total of 78 articles and 56 original models based on their structure, inclusion of pests,and cropping practices.Results: We identified 35 articles using pest models to simulate pest injuries; 34 articles using crop models tosimulate the pest damages on yield losses; and 9 articles using crop-pest models to simulate the interactionsbetween pest dynamics and crop growth.Conclusions: Different types of models offer different uses for ACP strategies. An innovative conceptual model foragroecological rice protection is proposed.Implications or significance: The presented review is a springboard to future modeling developments useful foragroecological rice protection. Combined with other approaches, such as field experiments and demonstrations,farmer workshops, teaching and training, specific advices to farmers, modeling approaches can help design moresustainable rice-based cropping systems.

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Institut national de la recherche agronomique - France

2023

DAYAL, PARMESWAR | KUMAR, ARUN | TYAGI, SHASHANK | PAL, RAVIKESH KUMAR | MANOHAR, BAL | RANJAN, SHIVANI | SOW, SUMIT

The reduced yield under conventional tillage is due to more crop-weed competition and more dry matter accumulation by the weeds(Kumar et al. 2018). Due to zero weed competition, weed-free treatments yielded the highest grain yield of all weed managementpractices. In contrast to this, the lowest grain yield was obtained in weedy treatment due to season-long weed competition. Maximum yield under W8 is due to broadspectrum activity of these herbicides (Sharma et al. 2014, Sunil et al. 2021). The use of zero tillage reduced weed incidence and suppression, leading to higher grain yields. Therefore, zero tillage and metsulfuron 20% wp 4 g a.i./ha + clodinafop propargyl 15% wp 60 g a.i./ha should be practiced for minimizing weed growth and maximizing the yield.

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Indian Council of Agricultural Research - India

2023

Kurdyukova, O.N.

The results of long-term (2008-2022) field experiments established on two types of soils (chernozem and chestnut soils) are presented. The experimental sites were located in the Northern Steppe and Arid Steppe, respectively. The indicators of average seed productivity of more than 50 species of weeds growing in these soils are presented. The duration of the viability of seeds planted in a 0-30 cm soil layer, the quality of seeds during their layer-by-layer placement in the soil, on its surface and during storage in a dry warehouse is indicated. It was revealed that early spring and wintering weeds in chernozem soils had the highest seed productivity (more than 50 thousand seeds per plant). It was established that these seeds remained viable in the soil from 3 to 6 years (23 species), more than 6 years (20 species), and less than 3 years (only 3 species). In chestnut soils, the seed productivity of most weeds decreased by 11-26% compared to chernozems. The loss of seed viability occurred more intensively in chestnut soils than in chernozem soils. It was established that the lowest viability of seeds on both types of soils was observed during their long-term stay on the soil surface: after 5 years it did not exceed 12-15%, and after 10 years - 2-3%, while being placed in the 0-10 cm layer of chernozem soils, it reached 36 and 18%, respectively, and in chestnut soils it decreased more strongly and did not exceed 26 and 10%. In the lower soil layers, 10-20 and 20-30 cm, higher viability of weed seeds remained in chestnut soils. Seeds of native weedy plant species typical for chernozem or chestnut soils remain viable longer than seeds of foreign species. | Приведены результаты многолетних (2008-2022) полевых опытов, заложенных на двух типах почв: черноземных и каштановых. Опытные участки располагались в Северной Степи и Засушливой Степи соответственно. Представлены показатели средней семенной продуктивности более чем 50 видов сорных растений, произрастающих на этих почвах, указана продолжительность жизнеспособности семян, заложенных в слое 0-30 см почвы, качество семян при послойном их размещении в почве, на ее поверхности и при хранении в условиях сухого складского помещения. Выявлено, что самой высокой семенной продуктивностью отличались яровые ранние и зимующие сорные растения на черноземных почвах (более 50 тыс. шт. семян с растения). Установлено, что данные семена сохраняли жизнеспособность в почве от 3 до 6 лет (23 вида) или более 6 лет - 20 видов, и только 3 вида - менее 3 лет. На каштановых почвах семенная продуктивность большинства сорных растений снижалась на 11-26% по сравнению с черноземами. Потеря жизнеспособности семян происходила более интенсивно на каштановых почвах, чем на черноземных. Установлено, что самая низкая жизнеспособность семян на обоих типах почв отмечалась при многолетнем пребывании их на поверхности почвы: через 5 лет она не превышала 12-15%, а через 10 лет - 2-3%, тогда как при расположении в слое 0-10 см черноземных почв она достигала соответственно 36 и 18%, а на каштановых снижалась сильнее и не превышала 26 и 10%. В нижележащих слоях почвы, 10-20 и 20-30 см, более высокая жизнеспособность семян сорных растений оставалась на каштановых почвах. Семена аборигенных сорных видов растений, типичных для черноземных или каштановых почв, дольше остаются жизнеспособными, чем семена заносных чужеродных видов.

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Central Scientific Agricultural Library - Russian Federation

2023

Golubev, A.S.

The data of field small-plot trials with the new herbicide Versia, OD (propisochlor 370 g/L + terbuthylazine 185 g/L) carried out in 2021-2022 on soybean, sunflower, and corn crops in regions of the Russian Federation with different climatic conditions: the Altai, Krasnodar, Moscow, and Astrakhan regions. The number and weight of weeds were counted on 4 x 0.25 m2 sized sites on each plot. The counts were carried out 30 and 45 days after the crop treatments. There were revealed from 83 to 190 species of annual dicotyledonous and gramineous weeds per 1 m2 of untreated reference plot. The use of new herbicide Versia, OD before emergence of crops at application rates of 3.0-4.0 L/ha has been found to significantly reduce the infestation with annual dicotyledonous and gramineous weeds. The application of 4 L/ha of the herbicide makes it possible to prevent the appearance 90-95% of yellow foxtail, 80-94% of lambsquarter goosefoot, 76-94% of barn grass, 67-93% of pigweed, and 64-93% of China jute. The use of the herbicide, depending on the region, makes it possible to obtain additionally up to 364 c/ha of corn herbage, up to 22.8 c/ha of corn grain, up to 9.9 c/ha of sunflower seeds, and up to 9.9 c/ha of soybean seeds. To achieve the greatest use efficiency on weeds, the herbicide should be used in conditions of sufficient moistening. | Проанализированы данные полевых мелкоделяночных опытов с новым отечественным гербицидом Версия, МД (370 г/л пропизохлора + 185 г/л тербутилазина), проведенные в 2021-2022 гг. на посевах сои, подсолнечника и кукурузы в различающихся по климатическим условиям регионах Российской Федерации: Алтайском и Краснодарском краях, в Московской и Астраханской областях. Количество и массу сорных растений подсчитывали на 4 учетных площадках размером 0,25 м2 на каждой делянке опыта. Учеты проводили через 30 и 45 суток после обработки посевов. На 1 м2 необработанного контроля насчитывалось от 83 до 190 экземпляров однолетних двудольных и злаковых сорных растений. Установлено, что использование препарата Версия, МД до всходов с.-х. культур в нормах применения 3,0-4,0 л/га существенно снижает их засоренность однолетними двудольными и злаковыми сорняками. Внесение 4,0 л/га препарата позволяет предотвратить появление 90-95% растений щетинника сизого, 80-94% мари белой, 76-94% ежовника обыкновенного, 67-93% щирицы запрокинутой и 64-93% канатника Теофраста. Использование препарата в зависимости от региона применения позволяет получить дополнительно до 364 ц/га зеленой массы кукурузы, до 22,8 ц/га зерна кукурузы, до 9,9 ц/га семян подсолнечника и до 9,9 ц/га семян сои. Для достижения наибольшей эффективности влияния на сорные растения препарат следует использовать в условиях достаточного увлажнения.

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Central Scientific Agricultural Library - Russian Federation

2023

Ehbel', А.L. | Ehbel', T.V. | Mikhajlova, S.I.

Members of the Brassicaceae family are of great significance as weeds and invasive plants; they are one of the leading families of the alien fraction in the segetal floras of various regions of Russia. Among the cruciferous weeds growing over Russia, there are many species that are wild relatives to cultivated plants. Some cultivated species grow outside of their cultivation areas as ruderal and segetal plants. Among the cruciferous plants growing in Russia, 28 species out of 19 genera are regulated as harmful organisms in 33 different countries. Most of the species from this list are widespread weeds in Russia. To establish the presence of Brassicaceae species in Russian agrocenoses, we analyzed published sources, herbarium materials stored in the Russian leading herbaria, and materials collected by the authors during field explorations in 2017–2022 in 19 subject entities of the Russian Federation. Identification of cruciferous plants is often a rather difficult task, so the goal of this work was to develop a convenient identification key that would make it possible to identify weeds of this family found in Russian agrocenoses. Most of the available keys are designed for fruit-bearing specimens of cruciferous plants. For phytosanitary purposes, it is important to identify plants prior to their fruiting period. Therefore, we additionally used the characters of flowering plants (including their vegetative organs) enabling us to identify cruciferous plants at the flowering stage. Based on such features, a table was made, which included all weedy species of Brassicaceae found in agrocenoses within Russia (83 species in total). On the basis of this table, an identification key was produced for the identification of genera and some species of weedy cruciferous plants. Afterwards, fractional species-specific keys were made for the genera containing species controllable in importing countries. | Крестоцветные (Brassicaceae) имеют большое значение как сорные и инвазивные растения, являются одним из ведущих семейств чужеродной фракции в сегетальных флорах различных регионов России. Среди сорных крестоцветных, произрастающих на территории Российской Федерации, многие виды являются дикими родичами культурных растений. Некоторые культивируемые виды произрастают за пределами мест выращивания как сорняки. Из встречающихся в агроценозах РФ крестоцветных 28 видов из 19 родов входят в перечни регулируемых вредных организмов 33 стран-импортеров продукции российского растениеводства. Большая часть этих видов – широко распространенные в РФ сорно-полевые растения. Для установления присутствия видов Brassicaceae в агроценозах проанализированы литературные источники, гербарные материалы из ведущих гербариев России, а также собранные авторами при полевых исследованиях в 2017–2022 гг. в 19 субъектах РФ. Определение крестоцветных часто является сложной задачей, поэтому целью работы явилось создание удобного ключа, позволяющего определить встречающиеся в агроценозах России сорняки этого семейства. Большинство имеющихся ключей составлено для плодоносящих экземпляров крестоцветных. Для целей фитосанитарии важно определение растений до начала плодоношения. Поэтому авторами были дополнительно использованы признаки, позволяющие определить крестоцветные уже в стадии цветения. На основе значимых признаков 83 отмеченных в агроценозах РФ видов Brassicaceae был разработан идентификационный ключ для определения родов и некоторых видов сорных крестоцветных. Для родов, в которых есть регулируемые странами-импортерами виды, составлены частные видовые ключи.

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Central Scientific Agricultural Library - Russian Federation

2023

Le Bourgeois, Thomas | Marnotte, Pascal | Botanique et Modélisation de l'Architecture des Plantes et des Végétations

Institut national de la recherche agronomique - France

2023

Marija Ravlić | Renata Baličević | Toni Svalina | Diana Posavac | Jelena Ravlić

Medicinal and aromatic plants with allelopathic effect are a potential source of natural herbicides. The experiment was conducted in order to assess herbicidal potential of meadow sage (Salvia pratensis L.) on germination and growth of weed species velvetleaf (Abutilon theophrasti Med.) and common corn-cockle (Agrostemma githago L.). Water extracts from S. pratensis dry biomass in different concentrations were evaluated under controlled laboratory conditions in Petri dish bioassay. Herbicidal effect of S. pratensis extracts depended on the extract concentration and weed species. In general, higher concentrations of water extract showed greater negative effect on germination and growth parameters of weed seedlings. A. githago had greater sensitivity to S. pratensis extracts with reductions in germination and seedlings growth up to 100% in treatments with 7.5% and 10% extract concentrations. A. theophrasti germination was not affected by water extracts, however, substantial reductions of root and shoot length as well as fresh weight of seedlings were recorded. S. pratensis proved as promising plant species for further studies.

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Directory of Open Access Journals - Sweden

2023

Dubravko Filipović | Josip Lakić | Mateja Grubor | Igor Kovačev | Krešimir Čopec

An experiment with different variants of weed control in the maize crop was carried out in 2021 at a location next to the Markovo Polje settlement on silty loam soil. Three variants of weed control were applied: 1. mechanical weed control between the maize rows with a motocultivator and manual hoeing within the rows, 2. mechanical weed control only between the maize rows with a motocultivator without control within the rows, 3. without any control of weeds. In the experimental field, 14 different types of weeds were found, of which Amaranthus retroflexus, Ambrosia artemisiifolia, Chenopodium album and Sorghum halepense prevailed. As expected, the lowest weed infestation of the experimental plots was on the plots where variant 1 of weed control was applied, in variant 2 the average mass of weeds per 1 m2 was 223%, and in variant 3 it was even 334% higher compared to variant 1. Maize yields were inversely proportional to the weed infestation of the experimental plots, the highest yields were achieved in variant 1 with an average of 6015 kg ha-1, in variant 2 the average yield was 2907 kg ha-1, and in variant 3 1242 kg ha-1. The combination of mechanical weed control and manual hoeing can be an alternative to the use of herbicides on smaller family farms and in organic maize production.

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Directory of Open Access Journals - Sweden

2023

Sovika Bhattarai | Pramod Wagle | Biplov Dahal | Kalpana Jaggi

Weeds are the most important biotic constraints to groundnut production in Nepal. They hinder the plant growth and increase the cost of production. A field based study was conducted from June, 2022 to December, 2022 at Oilseed Research Program, Sarlahi, Nepal to study the effect of mulch on the productivity of groundnut. The experiment was laid out in randomized complete block design with 7 treatments viz., rice husk, rice straw, black polythene sheet, Lantana camara, living mulch, sawdust and control in three replications. The fertilizer dose used for groundnut was 20:40:20 NPK kg per hectare. The pod yield in rice husk mulch and living mulch treatments were significantly higher (2.07 and 1.84 tons per hectare, respectively) whereas the lowest yield (0.83 tons/hectare) was observed in plot with no treatment). Lower weed infestation with weed biomass 0.046 tons/ha for narrow leaf weeds and 0.021 tons/ha for broad leaf weeds was observed in L. camara mulching.  Rice husk mulching produced significantly higher number of pods (29 pods per plant) with the highest benefit cost ratio (1.15) whereas black polythene mulching produced lower number of pods (23 pods per plant) with lowest benefit cost ratio (-0.33). Conclusively, the study's finding suggests that rice husk can be used as a mulching material to increase the productivity of groundnut.

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Agriculture and Environmental Science Academy - India