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An increase in beet production at the present stage is possible only with the use of intensive technologies, where the integrated protection of crops from harmful organisms is of great social and economic importance. In the system of measures aimed at increasing the production of beetroots, an important place is the protection of sugar beets from diseases. Successful control of sugar beet diseases is an important reserve for increasing the yield and sugar content of root crops and improving their technological quality. A rather dangerous disease of sugar beet is the root eater, which is widespread throughout Ukraine, especially in the zone of sufficient moisture. Conducting studies to study the effect of certain agro technical measures, as more economically affordable, on the formation of harmful microorganisms that contribute to the development of root and other root diseases during the growing season, the effect of sugar beet concentration in crop rotation. In the experiments, various types of crop rotation were studied: grain-sowing, grain-cultivating (with green manure) and fruit-bearing. The technology for growing crops is generally accepted. Pesticides were not used in the experiments, with the exception of seed dressing. Studies have established that the main causative agent of the root in the conditions of the western forest-steppe of Ukraine are various species of fungi of the genus Fusarium i Aphanomyces cochliondes. The dominance of these pathogens among pathogens causes the most severe defeat of beets in the phase of the first pair of leaflets, as well as the death of plant diseases in a later period - after the formation of planting density. Studies have shown that the lowest prevalence of sugar beet diseases was observed at a saturation level of 17% when they were grown in one place after 5 years (the average degree of development of the root was 14.7%). The development of the disease increased with a decrease in the time of returning to the previous place of cultivation in the rotation. So, on average, over a three-year period, the reduction of this period to four to two years increased the degree of root beetle damage to 15.4-19.8%. At a one-year break and re-sowing, this indicator was 24.4% and 27.2%, respectively. Based on the results obtained, it can be argued that an increase in the concentration of sugar beets in the crop rotation leads to an increase in the distribution of the root.

This study investigated the effects of six crop rotation combinations on the soil quality of old apple orchard and seedling growth of Malus hupehensis Rehd. (apple rootstock) under pot conditions. The inhibitory effects of crops such as Allium fistulosum, Brassica juncea, and Triticum aestivum on four species of Fusarium were observed and compared in six treatments. These were continuous cropping (CK), fumigation with the methyl bromide (FM), rotating A. fistulosum only (R1), rotating A. fistulosum and T. aestivum (R2), rotating A. fistulosum, B. juncea, and T. aestivum (R3), and fallow (FC) in a year. The results showed that the biomass of Malus hupehensis Rehd. seedlings increased significantly. The root length increased and the root architecture was optimized. The respiration rate of the root system was increased by about 1 time after rotation. The treatments of R1, R2, R3, and FC increased bacterial count by 232.17%, 96.04%, 316.21%, and 60.02%, respectively. However, the fungi were reduced in varying degrees and bacteria/fungi ratio was increased by 5–10 times. The enzyme activities, pH, and organic matter were increased, but soil bulk density was decreased. Phenolic acids such as phloridzin was decreased significantly. The copy number of four Fusarium species declined by 85.59%, 74.94%, 69.68%, and 54.41% after rotating three different crops (R3 treatment). The root volatiles of three plants inhibited mycelial growth and spore germination of four Fusarium species.

Soybean cyst nematode (SCN; Heterodera glycines) is one of the devastating soybean pests worldwide, including in the United States. Resistant cultivars combined with crop rotation are the primary methods for managing this nematode. SCN is known to have genetically diverse populations and can develop new virulent forms over time due to the continuous planting of cultivars derived from same source of resistance. Thus, identifying novel SCN resistant sources is of paramount importance for soybean breeding for nematode resistance. In this study, we screened 149 early maturity soybean [Glycine max (L.)] accessions for resistance to SCN HG type 2.5.7, which is one of the prevalent virulent SCN populations in North Dakota. SCN white females were extracted from individual plants of each accession after 35 days of growth in greenhouse conditions. The females were counted to determine a female index (FI = [average number of females on a tested accession/average number of females in Barnes, a susceptible soybean check] × 100). The resistance response of each soybean accession was categorized as resistant, moderately resistant, moderately susceptible, and susceptible. Of the 149 soybean accessions tested, only 13 were resistant in both runs of the experiments. The majority of screened soybean accessions were susceptible or moderately susceptible to the SCN HG type 2.5.7. The resistant soybean accessions identified in this study have the potential to be used in breeding SCN-resistant cultivars after further elucidation of the resistance genes or loci.

We explored how long-term agricultural practices affect arbuscular mycorrhizal (AM) fungal traits and community structure. We sampled soil and roots from a 26-year-old field experiment comprising 16 replicated treatments, in which we manipulated tillage intensity (moldboard vs. chisel plow), fertilization (organic vs. mineral) and crop rotation (continuous barley vs barley-forage rotations) in a factorial design (N = 64). We measured AM fungal community-aggregated traits, namely the abundance of vesicles, arbuscules, extraradical mycelium (ERM) and spores. We characterized root-borne and soil-borne AM communities using Illumina sequencing. Crop rotation was the main factor controlling AM fungal traits, with more arbuscules and ERM found in forage rotation plots, and more vesicles and spores found in continuous barley plots. Members of the Glomeraceae family were preferentially associated with continuous barley whereas the Gigasporaceae and Diversisporaceae families were overrepresented in the first stage of crop rotation. Trait-based and phylogenic filtering of AM fungal communities allowed us to speculate on different life history strategies among taxonomic families. AM community structure in soil responded to fertilizer type, whereas root-borne communities responded to crop rotation. We found the first evidence of temporal niche partitioning as a potential driver of coexistence among AM fungal taxa, resulting in higher species richness (i.e. storage effects). Crop rotation scheme strongly influences functional traits and coexistence of AM fungi, more so than soil disturbance intensity or fertilization regime. Future work is required to understand the implications of these shifts in AM fungal community structure for crop productivity.

Alfalfa (Medicago sativa L.) establishment failure is often attributed to autotoxicity when alfalfa is reseeded shortly after termination of the previous alfalfa stand, but renovation/rotation strategies for irrigated semiarid, subtropical environments have not been studied. Two identical studies were initiated at the New Mexico State University Rex E. Kirksey Agricultural Science Center at Tucumcari, NM, USA to compare continuous alfalfa (ALF), a single year of rotation to sorghum-sudangrass (SS1, Sorghum bicolor × S. sudanense (Piper) Stapf), two years of rotation with sorghum-sudangrass (SS2), and winter wheat forage (Triticum aestivum L.) followed by a single season of sorghum-sudangrass (WW/SS). Soil type and renovation/rotation strategy may influence soil fertility prior to replanting alfalfa, but soil fertility did not appear to influence alfalfa re-establishment or first production year yields. With a Test x Rotation interaction due to differences between tests for WW/SS for first production year yield after September alfalfa replanting, the main effect of Rotation was significant for yield (6.43AB, 5.3B0, 6.92A, and 3.54C Mg ha−1 for ALF, SS1, SS2, and WW/SS, respectively, 5% LSD = 1.22). Alfalfa stand destruction and replanting with no intervening crop rotation may be feasible in sandy soils with irrigation in the semiarid, subtropical southwestern USA and similar environments.

The subterranean microbiota of plants is of great importance for plant growth and health, as root-associated microbes can perform crucial ecological functions. As the microbial environment of roots is extremely diverse, identifying keystone microorganisms in plant roots, rhizosphere, and bulk soil is a necessary step towards understanding the network of influence within the microbial community associated with roots and enhancing its beneficial elements. To target these hot spots of microbial interaction, we used inter-kingdom network analysis on the canola growth phase of a long-term cropping system diversification experiment conducted at four locations in the Canadian Prairies. Our aims were to verify whether bacterial and fungal communities of canola roots, rhizosphere, and bulk soil are related and influenced by diversification of the crop rotation system; to determine whether there are common or specific core fungi and bacteria in the roots, rhizosphere, and bulk soil under canola grown in different environments and with different levels of cropping system diversification; and to identify hub taxa at the inter-kingdom level that could play an important ecological role in the microbiota of canola. Our results showed that fungi were influenced by crop diversification, which was not the case on bacteria. We found no core microbiota in canola roots but identified three core fungi in the rhizosphere, one core mycobiota in the bulk soil, and one core bacterium shared by the rhizosphere and bulk soil. We identified two bacterial and one fungal hub taxa in the inter-kingdom networks of the canola rhizosphere, and one bacterial and two fungal hub taxa in the bulk soil. Among these inter-kingdom hub taxa, Bradyrhizobium sp. and Mortierella sp. are particularly influential on the microbial community and the plant. To our knowledge, this is the first inter-kingdom network analysis utilized to identify hot spots of interaction in canola microbial communities.

A pineapple-banana rotation was studied as a model system to investigate the potential emergence of a fungal-mediated disease-suppression in a soil highly infested with the pathogen Fusarium oxysporum causing the banana wilt disease. By using both field and pot experiments, the pineapple-banana rotation system resulted in a significant decrease of the pathogen number and next-stubble banana disease incidence (P

© 2021 The Authors. Plant Pathology published by John Wiley & Sons Ltd on behalf of British Society for Plant Pathology. This is an open access article under the terms of the Creative Commons Attribution License. https://creativecommons.org/licenses/by/4.0/

A cultura do crambe destaca-se como matéria-prima em potencial para formulação de biocombustíveis, ganhando espaço entre fontes de energias renováveis, além da aptidão para rotação de culturas e cobertura verde. Objetivou-se avaliar a resposta produtiva do crambe quando cultivado em diferentes espaçamentos e populações de plantas em distintas épocas de semeadura na região oeste do Paraná. Delineamento experimental foi de blocos casualizados, esquema fatorial 3x3x4, com três épocas de semeadura, três espaçamentos (17, 34 e 51 cm) e quatro densidades de plantas (60, 90, 120 e 150 plantas m2), com três repetições, perfazendo 108 parcelas, apresentando cada parcela 24 m2. A cultivar utilizada foi a ‘FMS Brilhante’. Os parâmetros avaliados foram: altura de planta, número de racemos por planta, comprimento médio dos racemos por planta, número de frutos por planta, número de frutos por racemo e produtividade. A semeadura do crambe realizada em 03/05/2014 foi a que proporcionou melhores resultados. A população de 120 plantas m2 favoreceu o melhor crescimento e frutificação de planta. O espaçamento entre linhas de 51 cm apresentou melhores respostas para produtividade. O emprego de maiores espaçamentos com densidades de plantas medianas, conciliadas a semeaduras precoces, favoreceram as características morfológicas e produtivas da planta crambe.

Maize lethal necrosis (MLN) is a viral disease caused by a co-infection of maize chlorotic mottle virus (MCMV) and any one of cereal viruses including sugarcane mosaic virus (SCMV), maize dwarf mosaic virus, wheat streak mosaic virus or Johnsongrass mosaic virus. MLN has been identified as the most devastating maize disease that causes the highest yield loss in major maize growing areas in Eastern Africa including Ethiopia. In this study, field assessment, laboratory, and greenhouse experiments were conducted using MCMV and SCMV infected maize residue and infested soil to: (1) assess the role of MLN infected maize residue and infested soil in the transmission of MLN causing viruses, and (2) determine the longevity of the viruses both in the infected maize residue and in the infested soils. Serological detection and back-inoculation test results showed that MCMV was detected and confirmed to be transmitted from infested soil to newly germinated maize seedlings. However, SCMV was neither detected in soil samples from infected fields nor transmitted to maize seedlings. The present study confirmed that MLN infested soil is an essential medium for the survival and spread of MCMV under natural conditions. Under experimental condition, MCMV remained persistent and transmissible up to 6 months to maize planted on MLN infested soil mixed with MLN infected maize residues. Proper management or clearing of crop residues in the field after harvest is necessary to minimize adverse effects of MLN on maize production. Crop rotation is also one of the ways of freeing the soil from MLN disease.

Despite being native to semi-arid environments, safflower (Carthamus tinctorius L.) growth, seed yield, and physiological responses under contrasting temperature and moisture conditions typically occurring in semi-arid regions are not fully understood. Thus, three field experiments and a greenhouse study were conducted to study the growth, yield, and physiological attributes of six safflower genotypes under different environmental conditions. Spring-sown and summer-sown plants were subjected to contrasting environmental conditions in two 4-replicate randomized complete block design (RCBD) field experiments. In the third field experiment (a 3-replicate split plot RCBD) and the greenhouse study (a 3-replicate RCBD), the safflower genotypes were subjected to different irrigation regimes of no stress to severe drought. Spring-sown safflower outperformed the summer-sown crop in terms of seed filling rate (SFR) by 93%, seeds head−1 by 62%, 1000-seeds weight by 30%, seed yield by 53%, oil concentration by 16% and protein concentrations by 22%. Plant dry mass (PDM) for the summer-sown safflower was 25% greater than the spring-sown one. In contrast to a 21% increase in seed protein concentration, severe drought led to notable decreases in leaf chlorophyll a (chl-a), chl-b and total chlorophyll (chl-tot) concentrations, leaf area, relative water content (RWC), catalase (CAT) and ascorbate peroxidase (APX) activities, membrane stability index (MSI), oil concentration, yield components and consequently seed yield (36%) and PDM (34%). Genotype Kouseh tended to maintain its seed yield and quality across the environmental conditions, potentiating this under-utilized crop as an alternative to be endorsed in crop rotations of semi-arid climates.

Dwindling water resources appear to become a great challenge threatening the future of sustainable rice cultivation as it consumes substantial amount of water available in agricultural farming par se. Ostensibly being a water-guzzling crop, aerobic rice could be a viable option requiring less irrigation water than conventional farming, instead. However, grain yield penalty while grown continuously is becoming a strong demerit for sustainable aerobic rice cultivation. A better understanding of the causes and concerns vis-a-vis alleviation mechanism suggested a long term field experiment studying rotational sequences with different non-rice crops in a system perspective mode. Thus, the current field study was conducted for consecutive five years exploring the potentiality of aerobic rice based crop rotations with maize, ground nut and green gram in view of promoting soil health resiliency for arresting grain yield decline during 2013–14 to 2017–18. The study revealed a perceptible depletion in soil quality parameters at the end of last year/5th year accounting around 2.70% soil organic carbon, 1.70% available nitrogen, 1.60% available phosphorus, 1.39% available potassium, 2.75% iron and 1.35% zinc as compared those in the 1st year of the study. Even the situations also aggravated root nematode populations, especially rice root knot (Meloidogyne graminicola) and root rot nematode (Hirschmanniella oryzae) that inhibited usual root growth pronouncing less volume (26.50 cc plant−1) and density (0.54 g cc−1). As a result, drastic depression in usual growth and development of continuously grown aerobic rice caused more than 50% grain yield (2.04 t ha−1) decline at the 5th year compared to that (4.30 t ha−1) at the initial 1st year. However, no detrimental impacts were visualized on rice while grown in yearly rotation with non-rice crops; instead, grain yield increased significantly, especially in rotation with groundnut or green gram (4.40–4.46 t ha−1). Additionally, rice grain protein content (6.92–7.0%) also enhanced as compared that (6.36%) at pure aerobic rice stands. Thus, implication of this current study could have far reaching consequences ensuring aerobic rice cultivation sustainable in a rotational sequence with ground nut/green gram even under the apprehension of irrigation water deficiency.

Бұл зерттеу жұмысында бүгінгі таңда үлкен сұранысқа ие, жоғары сапалы өсімдік майын өндіруге субтропикалық мәңгі жысыл өсімдік – зәйтүн ағашын өсіру көзделген. Аймақтың жағдайына ағаштың бейімделуі мен жерсінуіне ғылыми-тәжірибелік қызығу-шылық танылып, зерттеу жұмысының басым бағыты болып табылды. Мақалада, Қазақстанның оңтүстігіндегі егістік жерге алғаш рет Еуропалық зәйтүн ағашының (Olea europaea L.) -12 -140С суыққа төзімді Италия мемлекетінің Лесщино, (Leccino) және Пронтоио (Frontoio) екі жылдық сорттары, Түркия мемлекетінен климаттық өзгеріске төзімді Арвелина (Arvelina) бір жылдық сорты әкелініп, экзотаны өсіру технологиясы қарастырылған. «Olives» ЖШС жылыжай кешенінде - 586 дана және далалы жағдайда - 14 дана еуропалық зәйтүн ағаштары отырғызылды. Оның 31 данасы түрлі абиотиалық және биотиалық себептер, атап айтқанда суық пен аяз кезеңнің ұзақтығы әсерінен тіршілік қабілетін жойды. Қыстан шыққан жалпы ағаштар саны 408 дана, оның ішінде 102 данасының бір жылдық бұталардың ұштары 5-8 см үсік шалды. Жердің үстіңгі қабатының барлық бұталарын үсік шалып тамыр мойнынан қайта жаңа сабақтар түзілген ағаштар саны 206 дананы құрады. Италия елінен әкелінген ағаштардың екі сорты Лесщино, Фронтоио екі жылдық көшеттері біздің аймақтың жағдайына бейімделуге қабілетті екендігі, ал Түркия мемлекетінен әкелінген Арвелино көшеттік сорты бейімделуге бәсеңдеу екенін анықталды. Берілген тыңайтқыш мөлшерлеріне байланысты күрделі қоспалармен дайындалған 20-20-20 минералды тыңайтқыштарды сумен араластырып енгізу нұсқасы және күрделі қоспалармен дайындалған 20-20-20 минералды тыңайтқышын, гуматпен араластырып енгізген нұсқадағы экзоталардың сабақтарының саны мен жапырақтарының түзілуі басқа нұсқаларға қарағанда жоғары болғандығы анықталды.

There is growing interest in malting barley (Hordeum vulgare L.) production in the Northeastern United States. This crop must meet high quality standards for malting but can command a high price if these quality thresholds are met. A two-year field experiment was conducted from 2015 to 2017 to evaluate the impact of two leguminous cover crops, sunn hemp (Crotalaria juncea L.) and crimson clover (Trifolium incarnatum L.), on subsequent winter malting barley production. Four cover crop treatments—sunn hemp (SH), crimson clover (CC), sunn hemp and crimson clover mixture (SH + CC), and no cover crop (NC)—were grown before planting barley at three seeding rates (300, 350, and 400 seeds m−2). SH and SH + CC produced significantly more biomass and residual nitrogen than the CC and NC treatments. Higher barley seeding rates led to higher seedling density and winter survival. However, the subsequent spring and summer barley growth metrics, yield, and malting quality were not different in any of the treatments. There is much left to investigate in determining the best malting barley production practices in the Northeastern United States, but these results show that winter malting barley can be successfully integrated into crop rotations with leguminous plants without negative impacts on barley growth, yield, and grain quality.

Relevance. Multilevel pipe vegetation installations (MVTU) “Fitopiramida” are designed for hydroponic cultivation of different agricultural crops including tomatoes.Methods. To create F1 tomato hybrids for this technology the assessment of phenological stages passing of tomato lines on “Fitopiramida” MVTU was carried out. 19 breeding lines including 9 cherry tomato lines, 10 large-fruited tomato lines of indeterminate and determinate growth types were tested. These lines were used in various hybridization schemes to obtain F1 tomato heterotic hybrids for “Fitopiramida”.Results. According to the results of the conducted researches in conditions of low-volume technology “Fitopiramida” duration of periods “germination – beginning of flowering” ("G-BF") and “germination – beginning of ripening” ("G-BR") is significantly reduced. In cherry group lines “G-BR” period is shorter by 17.7 days at average, in large-fruited lines by 23-27.3 days at average depending on growth type. The difference in ripening time is more expressed in largefruited lines; border-grown Kb 183 line began ripening 35 days later. Shorter growing season makes it possible to carry out largest number of crop rotations per year to obtain maximum yield per area unit (in full year use greenhouses). Similar results were obtained in the tests of tomato varieties and F1 hybrids on “Fitopiramida” MWTU in 2019-2020 in terms of phenological stages passing acceleration and earlier fruiting of hydroponic grown tomatoes.

The invasion of the fall armyworm was first reported in Africa in the year 2016. It has since then spread to over 40 countries across Africa, Asia and Australia. Being a polyphagous insect, the potential devastation effects of fall armyworm are enormous, especially among smallholder farmers. Currently, most farmers rely on the use of synthetic pesticides for the control of this pest. Organic agriculture however usually has very limited synthetic products approved for the control of pests. Organic production system therefore often depends on ecological processes, biodiversity and cycles adapted to local conditions for the management of pest. This paper reviews the availablemanagement methods applicable to the control of fall armyworm that can be adopted in an organic agriculture setting. Agroecological methods such as the push-pull technology, crop rotation and other methods including the use of resistant varieties, pheromone traps and biocontrol agents form an important control building block. Integrating these methods in a manner that is acceptable for organic certification will need further research, but it is certainly the way to go in combating the menace of the fall armyworm in organic agricultureand were reviewed in this paper.

Soil microorganisms are essential for the long-term sustainability of agricultural ecosystems. However, continuous grapevine replanting can disrupt the stability of soil microbial communities. We investigated the bacterial and fungal abundance, diversity, and community composition in rhizosphere soils with continuous grapevine replanting for 5, 6, 7 (Y5, Y6, and Y7; short-term), and 20 (Y20; long-term) years with high-throughput sequencing. Results showed that diversities and abundances of bacterial and fungal communities in Y20 were significantly lower than in other samples. The bacterial and fungal community compositions were markedly affected by the replanting time and planting year. After short-term grapevine replanting, relative abundances of potential beneficial bacteria and harmful fungi in rhizosphere soils were higher compared to long-term planting. Bacterial and fungal communities were significantly correlated with available nitrogen (AN), available phosphorus, available potassium (AK), and pH. AK and AN were the primary soil factors related to the shift of bacterial and fungal communities. Bacterial and fungal co-occurrence patterns were remarkably affected by replanting time, showing that fallow land harbored co-occurrence networks more complex than those in other groups, with the Y20 group showing the lowest complexity. Then, we isolated the dominant fungi in grapevine rhizosphere soil after continuous replanting and verified the harmful effects of three candidate strains through pot experiments. The results showed that 12 days post-treating the soil with fungal spore suspensions significantly inhibited grapevine seedlings' growth, whereas Fusarium solani inhibited plant growth. Overall, we showed that F. solani might be a potentially harmful fungus related to grapevine replant diseases. KEY POINTS: • Continuous grapevine planting reduced soil microbe diversities/abundances. • Beneficial bacteria and harmful fungi increased after short-term replanting. • F. solani may be a harmful fungus related to grapevine replant diseases.

The damage caused by insect pest is the continual factor for the reduction of rice production. To date, 232 rice insect pest species are identified in Bangladesh and more than 100 species of insects are considered pests in rice production systems globally, but only about 20 - 33 species can cause significant economic loss. The major goal of this study is to explore all the possible ways of developed and proposed technologies for rice insect pests management and minimize economic losses. Insect pests cause 20% average yield loss in Asia where more than 90% of the world's rice is produced. In Bangladesh, outbreak of several insects such as rice hispa, leafroller, gallmidge, stem borers and brown planthopper (BPH) occurs as severe forms. Based on previous reports, yield loss can reach upto 62% in an outbreak situation due to hispa infestation. However, BPH can cause 44% yield loss in severe infestested field. To overcome the outbreaks in odd years and to keep the loss upto 5%, it is necessary to take some preventive measures such as planting of resistant or tolerant variety, stop insecticide spraying at early establishment of rice, establish early warning and forecasting system, avoid cultivation of susceptible variety and following crop rotation. Subsequent quick management options such as insecticidal treatment for specific insect pest should also be broadcasted through variety of information systems. Advanced genomic tool can be used to develop genetically modified insect and plants for sustainable pest management. In addition, to stipulate farmers not use insecticides at early crop stgae and minimize general annualized loss, some interventions including training rice farmers, regular field monitoring, digitalization in correct insect pests identification and their management (example; BRRI rice doctor mobile app), and demonstration in farmers field. Each technology itself solely or combination of two or more or all the packages can combat the insect pests, save natural enemies, harvest expected yield and contribute to safe food production in Bangladesh. Bangladesh Rice J. 25 (1) : 1-22, 2021

Goal. To determine patterns of formation of the main and by-products of crop production on typical chornozem. To assess the use of low-value parts of the crop for fertilizer in the system of organic farming. Methods. During an experiment established in 1962, 16 variants of field crop rotations were studied. An organic system of agriculture was applied with the use of only by-products of the crop for fertilizer: grain straw and sugar beet tops. Results. With long-term use of by-products without the use of mineral fertilizers in the Eastern Forest-Steppe of Ukraine on typical chornozem, legumes, on average, provide grain yield up to 2 t/ha, annual grasses — at the level of 15 t/ha green mass, and corn for silage up to 25 t/ha. The grain yield of winter wheat on pure fallow is 4.21 t/ha, after peas — 3.66, and after the rank — 3.42 t/ha with fluctuations in its ratio with straw from 1:1.2 to 1:1.7. The yield of sugar beet roots has an average level of 27 t/ha in the ratio of tops 1:0.4. The average grain yield of buckwheat is 1.2-1.3 t/ha in the absence of correlation with straw biomass, with fluctuations in the ratio between them from 1:1.6 to 1:3.5, and an average value of 1:2.2. The yield of spring barley after sugar beet and buckwheat had an average of 2.16 and 1.99 t/ha for the ratio of straw 1:1.34 and 1:1.35. Conclusions. Analysis of yield data in terms of the impact of crop rotations of the first crops on subsequent ones shows that predecessors mostly affect winter wheat and sugar beet. The obtained results make it possible to determine the production volumes of crop by-products according to the yield data of the main products to use them for fertilizer in the system of organic production.

Mucuna (Stizolobium pruriens) is widely used in agriculture as a green allowance and in crop rotation, due to its ability to fix nitrogen and recover degraded areas; without embargo, there is a slow and uneven germination. This study used some classical methods, together with the use of low-frequency ultrasound to accelerate and homogenize the germination and emergence of the seeds. The experiment was carried out at the Plant Tissue Cultivation Laboratory of the Ilha Solteira Campus, São Paulo, Brazil. The design used was a completely randomized one, with five replications, in a 3x6 factorial scheme, the factors being: three pre-treatments for latency break: mechanical scarification, thermal scarification, and without scarification with six levels of ultrasound exposure: 0, 1, 2, 3, 5, 8 min, totaling 18 treatments. For eight days the germination and the initial stages of the seedlings were controlled. The method without scarification subjected to 4.5 min of ultrasound can become an excellent alternative, since it presented greater germination vigor, while 3.14 min of exposure to ultrasound were enough to improve the emergence speed, regardless of the method used in the preparation of seeds. In conclusion, only with the use of low-frequency ultrasound, it is possible to improve both the germination speed index and the germination vigor, without the need for additional treatments.

The article presents the results of studies of the quantitative and specific composition of soil micromycetes in potato cultivation, depending on the intensity of irrigation in the north-east of Kazakhstan. During their growth in the soil, plants actively interact with its microflora, while microorganisms can have both positive and negative effects. Micromycetes produce mycotoxins that accumulate in food and, when ingested, cause liver damage and cancer. Some mycotoxins persist in the ground for a long time, and with improper agricultural processing, they accumulate in it, and are also removed from it to adjacent environments (surface reservoirs). As a result of the conducted studies, indicators of the quantitative and specific composition of fungi were obtained, antagonist fungi and toxin-forming species were identified. According to the results of the mycological analysis of soil samples, 39 isolates were isolated. During the study, the accumulation of toxin-forming species was found to be 43−54 % in all the studied variants. In the soil, when using irrigation, there are both pathogenic (18.1-50.0%) and saprophytic (50.0-81.9%) species of micromycetes, as well as toxin-forming species of fungi (46.2-55.6%) , which can cause different effects on the resistance of plants to potato diseases. The greatest number of pathogenic fungi, as well as toxin-forming fungi, was found when using limited watering of potatoes. The greatest number of pathogenic fungal species was observed in the variants with moderate irrigation −38.5 % (genera Fusarium − 30.8 %, Penicillium − 7.7 %), as well as in the variant with maximum irrigation – 50.0 % (genus Fusarium – 39.0%, from the genera Gliocladium and Aspergillus − 5.5%). Thus, the use of crop rotations and repeated fungicidal treatments carried out when growing potatoes does not guarantee the absence of pathogenic microorganisms in the soil, and the use of intensive watering provokes a stronger development of pathogenic microflora. New approaches to integrated potato protection are required.

Weedy rice (Oryza sativaL.) is among the most problematic weeds in rice (Oryza sativaL.) production. The commercialization of herbicide-resistant (HR) rice nearly two decades ago provided an effective tool to manage weedy rice; however, resistance evolution and volunteer HR hybrid rice kept weedy rice at the forefront of rice weed control needs. This research aimed to assess the prevalence and severity of weedy rice infestations, identify production practices that may have contributed to an increase in weedy rice, and determine control strategies that may still be effective on weedy rice across Arkansas and adjacent U.S. Midsouth locales. Two questionnaires, one for rice growers and consultants and one for County Extension agents (CEAs), were distributed through email and physical copies in 2020. Thirty-three respondents returned the rice grower (25) and consultant (8) survey, representing 26 and 7 counties in Arkansas and the Missouri Bootheel area, respectively, as well as four parishes in northeast Louisiana. Eighteen respondents returned the CEA survey. Respondents ranked weedy rice the third most problematic weed in rice, behindEchinochloaspp. andCyperusspp. The most common infestation levels reported in 78% of fields was less than 12 m−2. Crop rotation (64% growers/consultants, 50% CEAs) and HR rice technology (27% growers/consultants, 50% CEAs) were the top two most-effective methods for weedy rice management, respectively. Tillage and crop rotation practices significantly influenced weedy rice infestation. Rice–soybean [Glycine max(L.) Merr.] rotation had the lowest weedy rice infestation compared with rice monoculture and other crop rotation practices. Crop rotation was not practiced on 26% of reported fields, primarily due to poor drainage. The imidazolinone (IMI)-resistant rice technology was still effective (>70% control) in 60% of fields, but quizalofop-resistant rice is needed to control IMI-resistant weedy rice. Overall, weedy rice remains a challenging weed in rice production.

The genetic diversity of the world gene pool of collecting samples from the Federal Research Centre of All-Russian Institute of Plant Genetic Resources named after N.I. Vavilov (VIR) was studied in the conditions of the southern forest-steppe zone of Western Siberia. N.I. Vavilov (VIR) by economically valuable traits and grain quality. The study was conducted in four stages as the gene pool became available: 2000-2003, 2007-2008, 2009-2012, 2019-2020. A total of 186 samples were studied. The following varieties recommended by the State Commission of the Russian Federation were used as standards: Altai Niva, Omskaya Amber, Zhemchuzhina Sibiri. Sowing was carried out on May 1516 by fallow in the specialised crop rotation of the durum wheat breeding laboratory of the Omsk Research Center. The material received in the first year was studied in plots with an area of 0.25 m2, and in subsequent years 3 m2. Agroclimatic conditions varied from favourable to contrasting temperature and water regimes. In studies of durum wheat samples from the VIR collection of different origins, sources were identified according to their economic value. Of the diversity, only a small part (10%) is of breeding interest and can be used in hybridisation. The sources of high productivity may be the samples k-59881, k-59888, k-60388, k-60364, k-60366, k-60413, k-61303, k-62657, k-62658, k-63126, k-63160, k-64353, k-64355, k-6386, k-64953, k-61619, k-63821, Sladunitsa, k-66887, k-66886, k-66293, k-66294, k-66519, k-66675, k-64488. In terms of grain quality the following crops stood out: k-59881, k-59889, k-60388, k-60364, k-61117, k-61650, k-62657, k-64353, k-64354, k-64355, k-6386, k-17985, k-63821, Sladunitsa, Iride, k-60410. As sources of resistance to stem rust, we offer k-6386, k-6662, k-46983, k-60410, Iride, k-65353, k-65733, k-65734. According to the complex of traits (high productivity, grain quality and resistance to diseases) are of breeding value samples k-59881 (Russia), k-6386 (Georgia), k-65734 (Syria), Sladunitsa (Ukraine) and Iride (Italy).

Fungal diseases represent a widely spread natural phenomenon affecting many of wild and domesticated plants. In nature, all plant species forms plant communities of a mixed character, and the spatial pattern of dominant species is usually irregular and spotted. Some species are impregnable to a certain infection, which provides a kind of natural barrier to the infection spread within the natural community. Under the agricultural environment, when the single plant species may occupy a huge area, the species-specific parasite takes a great advantage to develop focal outbreaks and fast spreading of the infection within the area. The concentration of vulnerable plants and the absence of natural barriers within the agricultural areas provokes outbreaks of fungal diseases, that may have highly harmful consequences and result in significant yield losses. One of the purposes of the satellite optical data is an operative, cost-effective diagnostic and, in combination with climatic datasets and crop rotation information, a prognosis of fungal disease appearance and severity. In this paper, we describe the system of prognostic and monitoring measures to control the fungal diseases of wheat in Central Kazakhstan with special attention to septoria leaf blotch. The prognostic procedure provides a map of the probability of septoria leaf blotch appearance. The prognosis takes into consideration the combination of three main variables: the model of ecological niche for Septoria, the presence of wheat residue, and Vegetation Condition Index counted for the late spring (May) of the current year. The new spectral index, introduced in this paper, is the core component of monitoring activity. The index is sensitive to septoria leaf blotch severity at middle to late (stages 8-11, accordingly Feekes growth stages) periods of wheat development. Several other indices (RETA, VSDI, vegetation indices) may be of help in providing information on the spatial unevenness of wheat crops that may indicate the presence of fungal infection.

Relevance. The aim of the work was to study the influence of predecessors cultivated in three crop rotations with a short rotation on the weedness of fiber flax crops and the yield of flax products. The study was carried out in field experiments in 2016–2019, on medium and weakly acidic soddy-podzolic light and medium loamy soils of the Tver region with a high phosphorus content. Methods . As the precursors of fiber flax, vetch-oat mixture and white mustard were cultivated with post-cut cultivation of white mustard for green fertilization, and also repeated sowing of fiber flax was carried out in the same field for three years in a row after the predecessor of barley. Results . As a result of the studies, it was found that the greatest lowering the weediness of fiber flax crops and an increase in the yield of flax products was observed in the crop rotation with the cultivation of white mustard for green fertilization after the precursor of the vetch-oat mixture for green fodder and the introduction of the biofungicide Sternifag after the precursor of barley with the addition of 12 kg/ha of ammonium nitrate. There was a decrease in the number of stems of couch grass ( Agroperon repens ) by 2.8 times, a significant increase in the yield of fiber flax — by 5 dt/ha a compared with repeated cultivation of fiber flax in the same field and by 1.4 dt/ha compared with cultivation after barley without the use of biofungicide. At the same time, the yield of flax straw was 29.1 dt/ha, of flax stock 22.4 dt/ha, of flax fiber — 6 dt/ha. In the crop rotation with the sowing of fiber flax after barley in the same field for three years in a row, there was a decrease in the yield of flax fiber by 0.3 and 0.8 dt/ha, including fiber scutched flax — by 1.6 and 1.7 dt/ha in comparison with cultivation in crop rotations with post-harvest use of white mustard for green fertilization.

Among the diseases that have the potential to cause damage to flax (Linum usitatissimum L.) every year, the fungal disease pasmo, caused by Septoria linicola, is the most important. Fungicide application and a diverse crop rotation are the most important strategies to control this disease because there is little variation in resistance among flax cultivars. However, few fungicide products are available to flax growers. Field studies were conducted at four locations in Western Canada in 2014, 2015, and 2016 to determine the effect of two fungicide active ingredients applied singly and in combination: pyraclostrobin, fluxapyroxad, and fluxapyroxad + pyraclostrobin; and two application timings (early-flower, mid-flower, and at both stages) on pasmo disease severity, seed yield, and quality of flaxseed. The results indicated that among the three fungicide treatments, both pyraclostrobin and fluxapyroxad + pyraclostrobin controlled pasmo effectively; however, fluxapyroxad + pyraclostrobin was the most beneficial to improve the quality and quantity of the seed for most of the site-years. Disease severity in the fungicide-free control was 70%, and application of fluxapyroxad + pyraclostrobin decreased disease severity to 18%, followed by pyraclostrobin (23%) and fluxapyroxad (48%). Application of fluxapyroxad + pyraclostrobin also improved seed yield to 2,562 kg ha−1 compared with 1,874 kg ha−1 for the fungicide-free control, followed by pyraclostrobin (2,391 kg ha−1) and fluxapyroxad (2,340 kg ha−1). Fungicide application at early and mid-flowering stage had the same effects on disease severity and seed yield; however, seed quality was improved more when fungicide was applied at mid-flowering stage. Continuous use of the same fungicide may result in the development of fungicide insensitivity in the pathogen population. Thus, sensitivity of S. linicola isolates to pyraclostrobin and fluxapyroxad fungicides was determined by the spore germination and microtiter assay methods. Fungicide insensitivity was not detected among the 73 isolates of S. linicola tested against either of these fungicides.

The biggest problem of Hungarian crop farming is mass production and the simple crop rotation based on cereals. There was a decrease in sowing area of protein crops which raises crucial issues in crop rotation and land use. Therefore, growing papilionaceous plants, which are now considered to be alternative plants, should be taken under close examination. Hairy vetch (Vicia villosa Roth.) belongs to the family of papilionaceous plants and it can be grown in light weak soils. In Hungary, hairy vetch was used as green forage at first, but it later became a green manure plant. Nowadays, it is used as a cover crop and its sowing seed has a good export market. In low fertile soils it is able to produce a big amount of green yield (25–40 t ha-1) even in spring while its seed yield could be 0.4–0.5 t ha-1 at farm level. In addition to its morphological characteristics hairy vetch is grown mainly with a supporting plant, i.e. triticale in many cases. Our purpose was to test the harvest index and its agrotechnical and botanical factors of hairy vetch in different cropping systems.

The purpose of the research is a demonstration field experiment on testing nematode-resistant potato varieties on a collective farm in focal point of golden potato nematode (GPN).Materials and methods. A demonstration field experiment on testing 7 nematode-resistant and 2 susceptible potato varieties was performed in the village of Parakhino, Gus-Khrustalny District, Vladimir Region, in a small family garden with significant evidences of potato globoderosis. The family garden was divided into 27 plots. The plot area was 100 m2 . In spring and autumn, 500 cm3 soil samples were taken from each plot. The soil samples were studied by the flotation funnel method. In growing season, we measured the height of plants, counted the number of stems, estimated the color, considered the uniformity and projected coverage of grass stand of the soil, assessed the globoderosis development, and determined the number of female GPN and their development on plant roots. During the harvesting period, we took into account the number and weight of potato tubers (standard and nonstandard) in 25 plants on each plot and the number of plants on the plot, and determined potato yields. We calculated the biological and economic effectiveness of growing nematode-resistant potato varieties.Results and discussion. The demonstration field experiments of 7 nematode-resistant potato varieties using modern mechanized potato cultivation techniques in the globoderosis focus faced by high infective rate (pre-plant density of the GPN population was 9.7–10 thousand eggs and larvae per 100 cm3 of soil) showed that the nematode-resistant varieties of Saturna, Lady Rosetta, Lady Claire, Malinovka, Latonna, Skarb, Zhukovsky Ranny surpassed susceptible cultivar Udacha (standard) in biological effectiveness (57–85%), economic effectiveness (4.9–134%) and economic benefit (87–409%). In susceptible cultivars Udacha and Germes, the globoderosis development was above 53%. In the tested nematode-resistant cultivars, the globoderosis development was poorly expressed (15–26%). Nematode-resistant cultivars Lady Claire, Lady Rosetta and Saturna, which showed the highest levels of profitability, economic efficiency, and high rates of decrease in the GPN population density in the soil can be recommended for cultivation in the fields of the Rossiya agricultural company. Susceptible cultivar Germes, which has shown good performance in terms of economic effectiveness and benefit can be recommended for cultivation in the crop rotation fields of the Rossiya agricultural company. Nematode-resistant cultivars Malinovka, Skarb, Latonna and Zhukovsky Ranny, which showed less economic effectiveness and benefit as compared to potato varieties for chips can be recommended for cultivation in private plots if cultivated using modern technology.

In agroecosystems, temporal diversification creates a sequence of short-lived habitats through time. Crop species as well as the diversity of crops grown in sequence might affect soil biodiversity and nutrient cycling processes. In the present study, we focused on a long-term crop rotation established in 2006 in Lower Saxony, Germany on a Luvisol. Winter wheat (WW) and silage maize (SM) were grown in continuous cultivation as well as in rotations. WW rotations span up to six years (including silage maize, sugar beet, winter rape and/or grain pea). Over two years, microbial biomass carbon (MBC) as well as kinetics (Michaelis-Menten Vmax and Km) of extracellular hydrolytic enzymes (β-glucosidase (BG), N-acetyl-β-glucosaminidase (NAG) and acid phosphomonoesterase (AP)) were measured in topsoil (0–10 cm depth) three times during the growing season. Continuous wheat increased soil microbial parameters compared to continuous maize as indicated by the higher microbial biomass to soil organic carbon ratio and higher potential enzymes activities involved in the C- and N-cycles (Vmax of BG and NAG). The efficiency of these enzymes was lowest in continuous maize (highest Km of BG and NAG). Maize and sugar beet as preceding crop of WW significantly decreased MBC in the 1st year but not in the 2nd year WW. Sugar beet decreased BG activity as well as its substrate affinity (increased Km). The effect of sugar beet on MBC and enzyme kinetics depended on the preceding crop and lessened with grain pea as the preceding crop. Soil microorganisms in the wheat phase benefited from winter rape as the preceding crop, shown by an increased biomass and efficiency to turn over chitin and peptidoglycan (decreased Km of NAG). Differences between cultivated crops, cropping history and fluctuations within the year in soil microbial biomass and enzyme kinetics are shown.

This study aims to evaluate the medium-term effect of two biannual rotations and four residue rate incorporation on durum wheat production and its nutritional composition and nutrient extraction. The effects of two biannual rotations of canola (Brassica napus L.) durum wheat (Triticum turgidum L.) and bean (Phaseolus vulgaris L.)-durum wheat and four incorporation rates (0%, 50%, 100%, and 200%) of residues of each preceding crop were evaluated after four seasons on durum wheat production and on its nutritional composition and nutrient extraction, in a volcanic soil in south-central Chile. Results indicated that the highest grain yield and residue production of durum wheat was obtained after bean (7.40 and 7.92 Mg ha−1, respectively). In the grain were obtained lower N and P concentrations after bean, and higher K, Ca, and Mg concentrations in the residue. The extraction of most durum wheat grain and residue nutrients was higher after bean. Nutrient distribution in the durum wheat plant concentrated in the grain was 79.9 to 80.7% N, 91.3 to 92.1% P, 27.1 to 27.4% K, 16.8 to 18.8% Ca, 68.3 to 70.4% Mg, and 56.3 to 57.4% S. In the residue, nutrient distribution was 19.3 to 20.4% N, 7.9 to 8.7% P, 72.6 to 72.9% K, 81.2 to 83.2%, Ca, 29.6 to 31.7% Mg, and 42.6 to 43.7% S. The highest grain and residue production of durum wheat was obtained after bean crop and also the extraction of most nutrients.

The integration of organic fertilisers into agricultural practices is one approach to enable more efficient agricultural management systems to decrease adverse environmental impacts of agriculture. In this context, the objective of this research was to determine the impact of long-term crop rotation and organic and mineral fertilisation on soil humus content, humic and fulvic acids, organic matter humification in organic and sustainable agricultural management systems with low (1.90–2.01%) and moderate (2.10–2.40%) initial humus contents. Long-term field experiments with different agricultural management systems started in 1960 at the Lithuanian Research Centre for Agriculture and Forestry and soil humus dynamics experiments were conducted from 2006 to 2017. Results of the long-term use of organic and sustainable agricultural management systems with different crop rotations and fertilisation revealed the positive effect of the applied supplies on soil humus, especially for farmyard manure in combination with green manure. The incorporation of farmyard manure and biomass of white mustard resulted in a lower degree of humification when compared to green manure alone, green manure + mineral N, and farmyard and green manure + mineral N. In the low humus content soil, the degree of humification under all agricultural management systems was significantly improved, on average by 0.9% compared to soil with a moderate humus content.

Crop rotation in fruit trees is an effective approach for addressing some of the problems of continuous cropping. To determine whether aged peach orchard soil is suitable for planting apple trees, we studied the effects of two substances abundant in aged peach orchard soil—amygdalin and benzoic acid—on the soil microbial community structure, soil enzyme activity, and the growth of Malus hupehensis Rehd. seedlings. Soils treated with amygdalin (T1), benzoic acid (T2), and a mixed solution of amygdalin and benzoic acid (T3) were used to plant M. hupehensis Rehd. seedlings. Compared with fallow (control) soil, the soil microbial community structure, soil enzyme activities, and root protective enzyme activities, leaf chlorophyll content, and net photosynthetic rate decreased in the three treatments. The biomass and root index of M. hupehensis Rehd. seedlings significantly decreased. Compared with T3, the plant height, ground diameter, fresh weight, dry weight, root length, root surface area, root volume, and root respiration rate of M. hupehensis Rehd. seedlings in T2 in 2015 (2016 in parentheses) decreased by 19.3% (12.6%), 8.7% (7.1%), 21.2% (13.3%), 9.1% (19.6%), 7.9% (25.3%), 40.7% (28.8%), 46.2% (21.1%), and 44.2% (27.5%), respectively. Compared with T3, the same variables in T1 in 2015 (2016 in parentheses) decreased by 34.9% (16.7%), 27.6% (9.8%), 53.6% (19.4%), and 50% (20.5%), 24.1% (31.4%), 55.1% (37.6%), 63.2% (28.2%), and 47.0% (28.7%), respectively. Thus, the inhibitory effect of T3 was the strongest, followed by T2 and T1. In sum, amygdalin and benzoic acid are harmful substances in aged peach orchard soil that inhibit the growth of M. hupehensis Rehd. seedlings.

The study examined the adoption determinants of adapted climate smart agriculture (CSA) technologies among smallholder farmers. A multi-stage sampling procedure was used to select a total sample of 384 households. Percentages and regression were employed in data analysis. The results revealed that 47.4% adapted to climate change using integrated farming system, intercropping, crop rotation and agroforestry. Sex (0.9%), education level (9.2%) significantly influenced adoption of the adaptation strategies. Moreover, information sources such as mobile phones (0.9%), and neighbors/friends (0.2%) negatively affected the adaptation strategies. Future policy should aim at creating more awareness through different information sources and provide local extension services. Keywords: Adaptation, smallholder farmers

Costs of production and organic price premiums are defining factors influencing the economic viability of organic crop production systems. Different agronomic practices, such as crop rotation and tillage intensity, are known to affect the economic performance of the production systems. The aim of this study was to compare the impact of two crop rotation sequences (simplified and diversified) and two levels of tillage intensity (high and low) on the cost of production, gross return and gross margin of crops when grown under organic management in the semi-arid Brown soil zone of the Canadian Prairies. The 2-year simplified rotation sequence consisted of forage pea (Pisum sativum L.) grown as a green manure followed by hard red spring wheat (HRSW) (Triticum aestivum L.), while the 4-year diversified rotation sequence was forage pea green manure followed by flax (Linum usitatissimum L.) or yellow mustard (Sinapis alba L.), field pea or lentil (Lens culinaris L.) and HRSW. Our hypothesis that a more diversified crop rotation would increase profitability over a traditional simplified crop rotation was supported by the findings. However, the findings did not support our hypothesis that reducing tillage intensity, and the combination of tillage reduction and diversified crop rotation through a synergetic response, would further enhance profitability. Analysis of the breakeven prices and breakeven yields for crops indicated the importance of adopting diversified crop rotations and choosing crops with high organic price premiums as means to maximize the long-term profitability of organic cropping systems.

Low soil fertility is one of the major constraints faced by smallholder farmers in the Bamboutos Mountain ecosystem. A survey of 261 randomly selected smallholder farmers was conducted using a standard questionnaire to identify the major cropping systems used by smallholder farmers, the practices that smallholder farmers use to maintain or improve soil fertility, the types of manure or fertilizer used as well as the major crops grown in the area. An interview schedule was used to collect data and the descriptive statistics used for data analysis. Findings indicated the farmers practiced, inter cropping, crop rotation and agroforestry with intercropping being the most practiced cropping system. The farmers use both organic manures and inorganic fertilizers for crop production with the major organic manure being fowl dropping and the major inorganic fertilizer being N-P-K 20-10-10. To increase soil fertility, 73% of the farmers allow for fallow periods and the dominant vegetation during the fallow were: grasses, grasses +Tithonia and Grasses + shrubs. The major crops planted both organically and with inorganic fertilizers were Potato, cabbage, carrot, maize, beans, leeks and celery.

The article summarizes the results of 1990-2012 research conducted during the stationary experiment on leached heavy loam chernozem in the Republic of Mordovia. The objects of the study are two crop rotations (grain-grass-fallow and grain-grass crop rotations) where alfalfa of the VEGA 87 variety was used as a bean component, smooth brome (Bromus inermis) Penza 1 was used as a grain component. It has been established that mineral fertilizers in grain-grass-fallow crop rotations with legumes increased productivity by 0.34-0.55, with cereals – by 0.31-0.73 tons of feed units/ha. That provided to get additional income from 1.19 to 1.40 and 1.09 to 1.47 rub/rub, respectively. Recommended doses of mineral fertilizers against soil liming by 0.5 hydrolytic acidity (h.a,) were N22-39P42K52, for grain-grass-fallow crop rotation with alfalfa and N27-71P42K52. with smooth brome. In the grain-grass crop rotation with legume and cereal components the payback of 1 kg active ingredient (a.i.) of complete mineral fertilizer was 6.13 and 6.17 kg feed units, additional income was 2.00 and 1.99 rub/rub, the productivity increased by 0.86-1.08 and 0.84-1.22 tons of feed units/ha, respectively. The payback of 1 kg of a. i. nitrogen as part of a complete mineral fertilizer in this crop rotation averaged 13.04 kg feed units versus 11.5 kg in legumes. Recommended doses of mineral fertilizers were N26-87P46K65 against the background of liming of the soil by 0.5-1.0 h. a. In crop rotation with smooth brome phosphorus-potash fertilizers should not be applied due to the low additional income (0.97-1.07 rub/rub).

Parthenium weed (Parthenium hysterophorus L.) is an invasive alien plant species that is spreading rapidly all over the world. With globalization and climate change, it will continue to spread, posing threats to agriculture, biodiversity and the environment. To determine its invasion and impacts in Bhutan, an investigation was undertaken in West-Central Bhutan using a questionnaire survey, complemented by MaxEnt modelling. Most farmers (19–30%) recall having seen parthenium for the last 11–15 years, or more. Infestations of parthenium differed significantly (P

The effects of one- and two-year maize-cover crop rotations on weed seed bank density and species composition were evaluated in fields at the University of Zimbabwe (UZ) and the International Maize and Wheat Improvement Center (CIMMYT, Harare) between 2014 and 2017. Nine cover crops were rotated, and maize and weed seed bank analyses were done using the seedling emergence method. Maize was used as the control. The results indicated that weed seed density was not significantly (p > 0.05) affected by cover crop mulch type across the seasons. There was a significant (p < 0.05) decline in weed density in the second maize phase of the rotation in UZ Field A. Bidens pilosa, Galinsoga parviflora, Amaranthus hybridus and Eleusine indica were the dominant weeds. B. pilosa density significantly decreased in the second season in UZ Field A but did not vary significantly among cover crops. Significant changes in weed species richness, evenness, and diversity were observed only in the second phase of the rotation in UZ Field A. The results suggest that maize-cover crop rotations could be effective in reducing seed bank size in the short term but have no short-term effect on weed species community composition.

Ethiopian mustard (Brassica carinata A. Braun) is a biofuel crop recently introduced in the southeastern United States. For this crop to be successful, integrated weed management strategies that complement its rotation with summer cash crops must be developed. The objectives of this research were to evaluate the effect of previous season summer crops on winter weed emergence patterns during Ethiopian mustard growing season and to assess the impact of planting Ethiopian mustard on the emergence patterns of summer weed species. Gompertz models were fit to winter and summer weed emergence patterns. All models represented more than 80% of the variation, with root mean-square error values less than 0.20. The emergence pattern for winter weed species was best described using growing degree-day accumulation, and this model can be utilized for implementing weed control strategies at the critical Ethiopian mustard growth stages. The results also showed that summer weeds can emerge during the winter in northern Florida but do not survive frost damage, which might create off-season seedbank reductions before the summer crop growing season.

In the period 2009–2018, an annual field survey with commercial arable farms in the Netherlands was held, to collect data on agronomics of wheat fields as well as mycotoxin concentrations of the specific wheat field at harvest. In total, 293 full farm field records over 8 years were obtained. This study aimed to investigate (i) the occurrence of deoxynivalenol (DON) and other mycotoxins, as well as correlations between these mycotoxins, and (ii) the relationships between agronomics and the DON concentration in wheat kernels for wheat cultivated in the Netherlands. Results showed that mycotoxins most frequently observed in concentrations above the limit of quantification were DON, enniatin B and B1, HT-2 toxin, zearalenone (ZEN) and nivalenol. On average, DON was detected in 54% of the samples (> 50 µg/kg) ranging from 19 to 92% depending on the year. Positive samples (> 50 µg/kg) had DON concentrations ranging 53–15,400 µg/kg, with a median of 228 µg/kg. Co-occurrence between DON and ZEN as well as between each of DON and ZEN with their modified forms was confirmed by the data of this study. The year influenced the DON concentration in wheat the most, followed by the region. The results of this study show that DON levels in wheat can only be influenced in a limited manner by agronomic practices such as the use of fungicides against Fusarium spp. around flowering, crop rotation, or the use of resistant wheat cultivars.

The paper presents the results of research on key vital parameters of a one-year late spring segetal species Setaria glauca (L.) P. Beauv. in crops of grain and legumes in the conditions of the north-rast forest-steppe Ukraine. It has been observed that in S. glauca there is a statistically significant change in the complex population characteristics, in particular, indicators of development of the vegetative sphere and reproductive organs against the background of changes in the field conditions. It turns out that the values of the main morphometric parameters and their dynamics in weed plants statistically significantly change by gradient of different crops, which are dominant agrocenoses and significantly affect the development of segetal wild species. It is proved that each cultivated plant is an edificator of agrocenosis and has a significant phytocoenotic effect on the state of S. glauca populations. The study found that favorable conditions for the development of weed emerged in fields of peas and winter wheat, while the crops of winter rye and buckwheat significantly inhibited the development of S. glauca populations. Knowledge of the dynamics of vital parameters of S. glauca populations under various field conditions allows the effective application of the system of anti-weed crop rotation, which allows controlling the clogging of fields using environmentally safe methods without application of herbicides.

The research was carried out to study the influence of biologization and chemicalization factors on the phytosanitary state of barley in the chain of the six-field fodder crop rotation of the second rotation in the forest-steppe of Western Siberia. The biologization factor was considered sowing peas to barley. The chemicalization factor was considered as the introduction of mineral fertilizers according to the results of agrochemical analysis at a dose of N60P20. It was found that the highest development of root rot was found in the variant with sowing barley without fertilizers, where the disease development index reached an average of 14.4% for the plant. The lowest one is in the variant “barley + peas + fertilizers’ (4.6%). In the variants “barley + peas’ and “barley + fertilizer”, the intensity of the disease was approximately the same and within the limits of the severity threshold – from 6.6 to 6.9 %. Similar data were obtained for the prevalence of the disease. Among the analyzed organs, the primary roots had the greatest damage, which was due to significant infection with Bipolaris sorokiniana Sacc. Damage by leaf-stem infections was almost 2 times lower in the variant with the use of the legume component and the application of fertilizers (16.8%) versus the control variant (31.8%). It was found that the correlation coefficient of the root rot development index on average for a plant with productive tillering was r = –0.63, and with plant height r = –0.99. Confirmation of the harmfulness of root rot is a close negative correlation between the yield and the indicators of the development of the disease on average for the plant: r = –0.74. It was found that the most favorable phytosanitary situation developed in the variant of sowing barley with the use of fertilizers and a legume component, which is associated with the healing effect of fertilizers and legumes, which is reflected, on the one hand, in increasing the endurance of the plant itself, and on the other, in an inhibitory effect on causative agents of the disease.

Weedy rice (WR) (Oryzaspp.) is the most troublesome weed infesting rice paddies in Brazil. Several changes have occurred in this region regarding crop management, especially WR control based on the Clearfield®(CL) rice production system launched in 2003. This survey’s objective was to evaluate the WR infestation status by assessing the producers’ perception and the management practices used in southern Brazil after 18 yr of CL use in Brazil. Rice consultants and extension agents distributed a questionnaire to 213 producers in the Rio Grande do Sul (RS) and Santa Catarina (SC) states in the 2018 to 2019 growing season. In RS, most farms are larger than 150 ha, and farmers have adopted the CL system for more than 2 yr and use minimal or conventional tillage, permanent flooding, clomazone PRE tank-mixed with glyphosate at the rice spiking stage, and crop rotation with soybean [Glycine max(L.) Merr.] or pasture. In SC, rice farms are small, averaging from 20 to 30 ha, farmers predominantly plant pre-germinated rice and do not rotate rice with other crops, and roguing is practiced. Comparing both states, the CL system is used in 99.5% and 69.3% of the total surveyed rice areas in RS and SC, respectively. Imidazolinone-resistant WR is present in 68.4% and 26.6% of rice farms in RS and SC, respectively. Rice cultivation in Brazil is currently coexisting with WR with minimal integration of control methods. However, integrated practices can control this weed and are fundamental to the sustainability of systems based on herbicide-resistant rice cultivars.

Among the methods of cultivation that increase the productivity of crops, a prominent role is assigned to crop rotation. In a properly constructed crop rotation, the efficiency of all agrotechnical methods aimed at improving the use of land increases, the biological needs of crops are satisfied, the rational use of technology is achieved, and the cost of production is reduced [1]. The soils are low in nitrogen, medium in phosphorus and high in potassium. The humus content is 1.2–2.0%, pH = 7–8. Studies have shown that green manure (sweet clover, oats, phacelia) have a positive effect on the balance of organic matter. The negative balance of organic matter is noted for pure steam. The stock of productive moisture in the 0–0.3 cm soil layer varied from 4.1 to 29.5 mm for winter wheat, 28.1–32.7 mm for chickpea and 28–35.3 mm for spring barley, depending on the weather conditions. conditions and methods of biologization. On average, over three years, the highest yield was in winter wheat for a busy fallow (phacelia) and amounted to 1.0 t/ha, which depended on weather conditions. A reliable correlation was revealed for the factors of yield-precipitation; temperature; batteries, etc.

Root rot caused by Fusarium species is a major problem in the pulse growing regions of Montana. Fusarium isolates (n = 112) were obtained from seeds and roots of chickpea, dry pea, and lentil. Isolates were identified by comparing the sequences of the internal transcribed spacer region and the translation elongation factor 1-α in Fusarium-ID database. Fusarium avenaceum was the most abundant species (28%), followed by F. acuminatum (21%), F. poae (13%), F. oxysporum (8%), F. culmorum (6%), F. redolens (6%), F. sporotrichioides (6%), F. solani (4%), F. graminearum (2%), F. torulosum (2%), and F. tricinctum (0.9%). The aggressiveness of a subset of 50 isolates that represent various sources of isolation was tested on three pulse crops and two cereal crops. Nonparametric analysis of variance conducted on ranks of disease severity indicated that F. avenaceum and F. solani isolates were highly aggressive on pea and chickpea. In lentil, F. avenaceum and F. culmorum were highly aggressive. In barley, F. avenaceum, F. solani, F. culmorum, and F. graminearum were highly aggressive. In wheat, F. avenaceum, F. graminearum, and F. culmorum were highly aggressive. Two F. avenaceum isolates were highly aggressive across all the crops tested and found to be cross-pathogenic. One isolate of F. culmorum and an isolate of F. graminearum obtained from chickpea and lentil seed were highly aggressive on barley and wheat. The results indicate that multiple Fusarium spp. from seeds and roots can cause root rot on both pulse and cereal crops. Rotating these crops may still lead to an increase in inoculum levels, making crop rotation limited in efficacy as a disease management strategy.

Verticillium wilt is a disastrous disease in cotton‐growing regions in China. As a common management method, cotton rotation with cereal crops is used to minimize the loss caused by Verticillium dahliae. However, the correlation between soil microbiome and the control of Verticillium wilt under a crop rotation system is unclear. Therefore, three cropping systems (fallow, cotton continuous cropping, and cotton–maize rotation) were designed and applied for three generations under greenhouse conditions to investigate the different responses of the soil microbial community. The soil used in this study was taken from a long‐term cotton continuous cropping field and inoculated with V. dahliae before use. Our results showed that the diversity of the soil bacterial community was increased under cotton–maize rotation, while the diversity of the fungal community was obviously decreased. Meanwhile, the structure and composition of the bacterial communities were similar even under the different cropping systems, but they differed in the soil fungal communities. Through microbial network interaction analysis, we found that Verticillium interacted with 17 bacterial genera, among which Terrabacter had the highest correlation with Verticillium. Furthermore, eight fungal and eight bacterial species were significantly correlated with V. dahliae. Collectively, this work aimed to study the interactions among V. dahliae, the soil microbiome, and plant hosts, and elucidate the relationship between crop rotation and soil microbiome, providing a new theoretical basis to screen the biological agents that may contribute to Verticillium wilt control., The effect of crop rotation on the soil fungal community is greater than that on the bacterial community, and the interaction between Verticillium dahliae and soil microbiome provides a theoretical basis for Verticillium wilt control.

An experiment to evaluate the effects of planting season and harvest dates on biomass production and nitrogen accumulation by sunn hemp was conducted at the Agricultural Research Station, Isabela, Puerto Rico. Sunn hemp Tropic Sun' was established in an Oxisol soil (Cotito series) at a seeding density of 10 kg/ha. Dry matter yield (DMY) was estimated at 71,92 and 121 days after planting (DAP) in June and November. Effects of both major variables were significant (P > 0.05) for DMY, the June planting far surpassing that of November (15,831 vs. 5,665 kg/ha); DMY increased progressively for the three harvest dates (7,704; 11,141; and 13,398 kg/ha). Maximun biomass production (20,734 kg/ha) was obtained at 121 DAP in June, thus exceeding by threefold that of November at 121 DAP (6,062 kg/ha). Nitrogen accumulation followed a similar pattern, with that of June surpassing that of November (352 vs. 147 kg/ha) and values ascending for the successive harvest dates (193, 254, and 303 kg/ha). Differences (P < 0.05) in N concentration were found by comparing the upper plant canopy with the lower. Expressed as crude protein (CP) the maximum value corresponded to that of the upper canopy at 92 DAP in November (19.0%), whereas the corresponding lower canopy value was only 4.72%. Based on its high biomass production and N accumulation, this legume could provide multiple beneficial effects when included in short crop rotations of sustainable production systems, taking advantage of the most favorable season and harvest stage. The present results suggest that 'Tropic Sun' planted in summer has good potential as a cover crop and green manure.