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1
Davidson, Campbell G. "Canadian wild plant germplasm of economic significance". Canadian Journal of Plant Science 75, n. 1 (1 gennaio 1995): 23–32. http://dx.doi.org/10.4141/cjps95-006.
Testo completoAbstract (sommario):
Canada is a large country with a great diversity of native plant material. Many of the native genera and species are related to crop plants. A review of different crop groupings revealed that over 30% of native plant material is related to crop species at the generic level. Fruit crops (111 species) and forage and turfgrass (138 species) crops had the highest number of related wild species. Nut crop species had relatively few native representatives (11 species) as did cereal, oilseed and other field crops (18 species). Special and minor acreage crops were represented by 86 species while landscape plants were represented by 137 genera. Forest trees are an important economic resource. Over 70 species of coniferous and deciduous trees are native to Canada. Many species, particularly in the fruit crop grouping, could be identified as world resources (e.g. Amelanchier) with the major part of their distribution occurring on Canadian soil. A concerted effort is needed to identify which species are endangered so that they can be preserved on a long-term basis. More research is needed to identify other long-term conservation goals coupled with crop development programs. Key words: Genetic conservation, Canada, wild plants, biodiversity
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Rector, Lucas S., Kara B. Pittman, Shawn C. Beam, Kevin W. Bamber, Charles W. Cahoon, William H. Frame e Michael L. Flessner. "Herbicide carryover to various fall-planted cover crop species". Weed Technology 34, n. 1 (22 agosto 2019): 25–34. http://dx.doi.org/10.1017/wet.2019.79.
Testo completoAbstract (sommario):
AbstractResidual herbicides applied to summer cash crops have the potential to injure subsequent winter annual cover crops, yet little information is available to guide growers’ choices. Field studies were conducted in 2016 and 2017 in Blacksburg and Suffolk, Virginia, to determine carryover of 30 herbicides commonly used in corn, soybean, or cotton on wheat, barley, cereal rye, oats, annual ryegrass, forage radish, Austrian winter pea, crimson clover, hairy vetch, and rapeseed cover crops. Herbicides were applied to bare ground either 14 wk before cover crop planting for a PRE timing or 10 wk for a POST timing. Visible injury was recorded 3 and 6 wk after planting (WAP), and cover crop biomass was collected 6 WAP. There were no differences observed in cover crop biomass among herbicide treatments, despite visible injury that suggested some residual herbicides have the potential to effect cover crop establishment. Visible injury on grass cover crop species did not exceed 20% from any herbicide. Fomesafen resulted in the greatest injury recorded on forage radish, with greater than 50% injury in 1 site-year. Trifloxysulfuron and atrazine resulted in greater than 20% visible injury on forage radish. Trifloxysulfuron resulted in the greatest injury (30%) observed on crimson clover in 1 site-year. Prosulfuron and isoxaflutole significantly injured rapeseed (17% to 21%). Results indicate that commonly used residual herbicides applied in the previous cash crop growing season result in little injury on grass cover crop species, and only a few residual herbicides could potentially affect the establishment of a forage radish, crimson clover, or rapeseed cover crop.
3
Hutianskyi, R., S. Popov, V. Zuza e N. Kuzmenko. "Weediness of corn for grain crops by cultivation in the stationary crop rotation and permanent crops in the Eastern Forest Steppe of Ukraine". Karantin i zahist roslin, n. 3 (26 settembre 2022): 15–19. http://dx.doi.org/10.36495/2312-0614.2022.3.15-19.
Testo completoAbstract (sommario):
Goal. To determine the species composition of weed plants and their dominant role, to establish the type and level of weediness of corn crops for grain grown in stationary crop rotation and monoculture in the conditions of the Eastern Forest Steppe of Ukraine.
Methods. The research was carried out by route surveys of crops in field experiments.
results. Аccording to the research data in 2011—2017 in corn sowing for grain found 33 types of weedy pollinators that belonged tо 17 families and contaminants were found in corn for grain crops, of which the most common were Asteraceae (9 species), Poaceae (4 species) and Polygonaceae (4 species). There were found 25% fewer species of weed plants (24 species) in corn for grain crops in monoculture than in crop rotation (32 species). Among weed plants, spring early and late species prevailed (65.6% — in crop rotation; 62.5% — in monoculture). The main types of weeds (occurrence of the species from 78 to 100%) in crop rotation were Setaria glauсa (L.) Beauv., Echinochloa crus-galli (L.) Roem. et Schult., Chenopodium album L., Amaranthus retroflexus L, Solanum nigrum L., Polygonum lapathifolium L., Cirsium arvense (L.) Scop., Convolvulus arvensis L., and in monoculture — C. album, Ambrosia artemisiifolia L., Xanthium strumarium L., C. arvense. According to the sum of the shares of dominance and subdominance among weed plants, C. arvense prevailed in crop rotation (78%), and X. strumarium prevailed in monoculture (100%). The type of weediness in corn for grain crops in crop rotation differed annually from the type of weediness in monoculture. For the most part, cereal annual weed species prevailed in crop rotation, and dicotyledonous weed species prevailed in monoculture. Under conditions of crop rotation, a lower level of weediness was observed almost every year than in monoculture.
Conclusions. The type of weediness in crops of corn for grain in crop rotation differs from the type of weediness in monoculture. for the most part, cereal annual weed species predominate in crop rotation, and dicotyledonous weed species predominate in monoculture.
4
Smith, Richard G., Lesley W. Atwood, Fredric W. Pollnac e Nicholas D. Warren. "Cover-Crop Species as Distinct Biotic Filters in Weed Community Assembly". Weed Science 63, n. 1 (marzo 2015): 282–95. http://dx.doi.org/10.1614/ws-d-14-00071.1.
Testo completoAbstract (sommario):
Cover crops represent a potentially important biological filter during weed community assembly in agroecosystems. This filtering could be considered directional if different cover-crop species result in weed communities with predictably different species composition. We examined the following four questions related to the potential filtering effects of cover crops in a field experiment involving five cover crops grown in monoculture and mixture: (1) Do cover crops differ in their effect on weed community composition? (2) Is competition more intense between cover crops and weeds that are in the same family or functional group? (3) Is competition more intense across weed functional types in a cover-crop mixture compared with cover crops grown in monocultures? (4) Within a cover-crop mixture, is a higher seeding rate associated with more effective biotic filtering of the weed community? We found some evidence that cover crops differentially filtered weed communities and that at least some of these filtering effects were due to differential biomass production across cover-crop species. Monocultures of buckwheat and sorghum–sudangrass reduced the number of weed species relative to the no-cover-crop control by an average of 36 and 59% (buckwheat) and 25 and 40% (sorghum–sudangrass) in 2011 and 2012, respectively. We found little evidence that competition intensity was dependent upon the family or functional classification of the cover crop or weeds, or that cover-crop mixtures were stronger assembly filters than the most effective monocultures. Although our results do not suggest that annual cover crops exert strong directional filtering during weed community assembly, our methodological framework for detecting such effects could be applied to similar future studies that incorporate a greater number of cover-crop species and are conducted under a greater range of cover-cropping conditions.
5
Dempewolf, H., P. Bordoni, L. H. Rieseberg e J. M. M. Engels. "Food Security: Crop Species Diversity". Science 328, n. 5975 (8 aprile 2010): 169–70. http://dx.doi.org/10.1126/science.328.5975.169-e.
Testo completo
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Somavilla, Alexandre, Karine Schoeninger, Dark Gabriela Dolzane Castro, Marcio Luiz Oliveira e Cristiane Krug. "Diversity of wasps (Hymenoptera: Vespidae) in conventional and organic guarana (Paullinia cupana var. sorbilis) crops in the Brazilian Amazon". Sociobiology 63, n. 4 (29 dicembre 2016): 1051. http://dx.doi.org/10.13102/sociobiology.v63i4.1178.
Testo completoAbstract (sommario):
Diversity of wasps (Hymenoptera: Vespidae) in conventional and organic guarana (Paullinia cupana var. sorbilis) crops in the Brazilian Amazon. The present study aimed to determine the diversity of wasp species associated with the guaraná crop and the difference in composition of species associated to organic and conventional crops, as well as among environments established in each management (adjacent forest, crop edge and guaraná crop). We collected 977 individuals and 59 species, in 23 genera of Vespidae, sixteen of Polistinae (52 species) and seven Eumeninae (seven species). Polybia was the most abundant and rich genus with 553 specimens and 15 species, followed by Agelaia (139, nine) and Protopolybia (103, five). In organic management crop, 686 individuals allocated in 18 genera and 47 species were collected, whereas in conventional management crop 291 individuals allocated in 18 genera and 41 species were collected. According to the three sampling points, in both management types, the edge of the crop field shows the highest abundance of wasps with a total of 519 individuals allocated in 19 genera and 45 species. Given the intense use of both environments (forest and crop) by the wasps, it is important to grow crops in regions near native forests, where the chances of social wasp colonies to be founded are increased.
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Cornelius, Cody D., e Kevin W. Bradley. "Herbicide Programs for the Termination of Various Cover Crop Species". Weed Technology 31, n. 4 (13 giugno 2017): 514–22. http://dx.doi.org/10.1017/wet.2017.20.
Testo completoAbstract (sommario):
The recent interest in cover crops as a component of Midwest corn and soybean production systems has led to a greater need to understand the most effective herbicide treatments for cover crop termination prior to planting corn or soybean. Previous research has shown that certain cover crop species can significantly reduce subsequent cash crop yields if not completely terminated. Two field experiments were conducted in 2013, 2014, and 2015 to determine the most effective herbicide program for the termination of winter wheat, cereal rye, crimson clover, Austrian winter pea, annual ryegrass, and hairy vetch; and cover crops were terminated in early April or early May. Visual control and above ground biomass reduction was determined 28 d after application (DAA). Control of grass cover crop species was often best with glyphosate alone or combined with 2,4-D, dicamba, or saflufenacil. The most consistent control of broadleaf cover crops occurred following treatment with glyphosate +2,4-D, dicamba, or saflufenacil. In general, control of cover crops was higher with early April applications compared to early May. In a separate study, control of 15-, 25-, and 75-cm tall annual ryegrass was highest with glyphosate at 2.8 kg ha−1or glyphosate at 1.4 kg ha−1plus clethodim at 0.136 kgha−1. Paraquat- or glufosinate-containing treatments did not provide adequate annual ryegrass control. For practitioners who desire higher levels of cover crop biomass, these results indicate that adequate levels of cover crop control can still be achieved in the late spring with certain herbicide treatments. But it is important to consider cover crop termination well in advance to ensure the most effective herbicide or herbicide combinations are used and the products are applied at the appropriate stage.
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Jaleta, Mulu, e Wondimagegnehu Tekalign. "Crop Loss and Damage by Primate Species in Southwest Ethiopia". International Journal of Ecology 2023 (6 gennaio 2023): 1–9. http://dx.doi.org/10.1155/2023/8332493.
Testo completoAbstract (sommario):
Crop damage is a major form of human-primate conflict that not only affects the livelihoods of farmers living close to forest areas but also threatens nonhuman primate conservation. This study aimed to investigate the causes of crop loss and foraging by nonhuman primates in southwest Ethiopia. For the purpose of gathering data, we used a questionnaire and direct observation. We employed simple random sampling techniques to select villages and respondents. From the nine selected villages, a total of 130 household samples were identified for the questionnaire. The primates responsible for crop damage were olive baboons and grivet monkeys. Maize, barley, teff, potatoes, sorghum, and other crops were among those foraged by the nonhuman primate species. Farmland close to the woodland boundary suffered more damage than farmland further away. The total amount of maize damaged by the olive baboons and grivet monkeys in the selected kebeles varied significantly. The majority of the respondents used guarding, and a few of them used scarecrows to protect crops from damage by primates. The highest crop damage occurred in the Atiro Tigre and Arigno Gefere villages, while the lowest occurred in the Sedecha villages. The flowering stage of the maize suffered the most, and the seedling stage suffered the least, from grivet monkeys foraging. The growth of crops that are less edible to nonhuman primates, especially on the forest edges, would lessen crop damage.
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McDonald, Philip M. "Estimating seed crops of conifer and hardwood species". Canadian Journal of Forest Research 22, n. 6 (1 giugno 1992): 832–38. http://dx.doi.org/10.1139/x92-112.
Testo completoAbstract (sommario):
Cone, acorn, and berry crops of ponderosa pine (Pinusponderosa Dougl. ex Laws. var. ponderosa), sugar pine (Pinuslambertiana Dougl.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), California white fir (Abiesconcolor var. lowiana (Gord.) Lemm.), incense-cedar (Libocedrusdecurrens Torr.), California black oak (Quercuskelloggii Newb.), tan oak (Lithocarpusdensiflorus (Hook. & Arn.) Rehd.), and Pacific madrone (Arbutusmenziesii Pursh) were evaluated over a 24-year period (1958–1981) from an area in northern California by an easy to use visual crop rating system. Seed-trap data, also for 24 years, were gathered for four conifer species. Together, these data provide the wild-land manager with knowledge on seed-crop quantity, quality, and timing. The visual rating system involves visually estimating the amount of fruit in trees and the proportion of trees with fruit, and ranking the crop by species. Regressions of sound seed and total seed on seed-crop rating are provided for the two species with the most seed crops: ponderosa pine and Douglas-fir. Regressions were significant at the 1% level, and coefficients of determination ranged from 0.58 to 0.76.
10
Majlingová, Andrea, Martin Lieskovský, Milan Oravec, Marek Trenčiansky e Rastislav Veľas. "Thermochemical properties of energy crop species planted in Slovakia". BioResources 16, n. 1 (8 dicembre 2020): 764–78. http://dx.doi.org/10.15376/biores.16.1.764-778.
Testo completoAbstract (sommario):
In the last decades, a new phenomenon has arisen in connection with temporary or permanent non-use of land for agricultural activity, namely the cultivation of energy crops in these localities, because of growing demand for biomass as a fuel. Farmers are expected to sell energy crops and the fuels they produce, both at home and in the surrounding countries. To choose economically efficient energy crop species to cultivate, the thermochemical parameters of the crop should be used to support decision-making process of farmers. This paper summarizes the results of small-scale laboratory tests of three energy crop species planted in Slovakia – Sida hermaphrodita, Arundo donax, and Miscanthus × giganteus – used for determination of thermal and chemical properties of the energy crop species to evaluate their suitability for energy purposes. The most suitable species for energy purposes was found to be Miscanthus × giganteus with higher heating value of 19.6 MJ/kg, lower heating value of 14.8 MJ/kg (at moisture content of 17%), and ash mass of 2.67% dry mass (d.m.). From a lignin mass and activation energy point of view, the most suitable for energy purposes was Arundo donax, with a lignin mass of 20.5% d.m. and an activation energy of 124.2 kJ/mol.
11
Tanveer, A., A. Khaliq, M. M. Javaid, M. N. Chaudhry e I. Awan. "Implications of weeds of genus euphorbia for crop production: a review". Planta Daninha 31, n. 3 (settembre 2013): 723–31. http://dx.doi.org/10.1590/s0100-83582013000300024.
Testo completoAbstract (sommario):
The genus Euphorbia comprises about 2000 species ranging from annuals to trees, including C3, C4, and CAM species. Euphorbia species widely studied in agriculture includes E. antiquorum, E. carollata, E. dentata, E. dracunculoides, E. esula, E. geniculata, E. granulata, E. helioscopia, E. heterophylla, E. hierosolymitana, E. hirta, E. maculata, E. microphylla, E. nerifolia, E. piluifera, E. pulcherrima, E. royleana, E. supine, and E. thiamifolia. These species have been reported mainly in field crops/vegetables, orchards, pastures, and rangelands. Euphorbia plants may present allelopathic effect over desirable cereals, pulses, oilseeds, vegetables, forage plants, and nitrifying bacteria, posing a serious threat to livestock production on open range lands through the release of allelochemicals from roots, stems, leaves, and inflorescence in the rhizosphere. Leaves are reported to be more toxic than other plant parts. Competition of Euphorbia spp. against crop plants is the most important crop yield-limiting factor. The critical period for Euphorbia competition with crops is reported to take place between 17 to 70 days after emergence for most crops, depending on root development during the initial crop growth stage, crop height, tillering or branching capacity, whether weeds emerge at the same time as the crop or later after crop emergence; how quickly crop canopy develops and also on Euphorbia species. A yield reduction of 4-85% has been reported in field crops with different Euphorbia species and distinct occurrence densities. Euphorbia species decrease herbage production by 10 to 100% in pasture and rangelands, with many acting as natural insecticide, fungicide, nematidicide, immunopotentiator, or immunosuppressor.
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Lanna, Anna C., Mariana A. Silva, Alécio S. Moreira, Adriano S. Nascente e Marta C. C. de Fillipi. "Improved nutrient uptake in three Crotalaria species inoculated with multifunctional microorganisms". Revista Brasileira de Engenharia Agrícola e Ambiental 25, n. 7 (luglio 2021): 460–65. http://dx.doi.org/10.1590/1807-1929/agriambi.v25n7p460-465.
Testo completoAbstract (sommario):
HIGHLIGHTS Multifunctional microorganisms promote the nutrient enrichment in Crotalaria plants. Cover crop residues are vital in managing soil fertility. Nutritionally improved cover crops increase soil nutrient levels for the subsequent crop.
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Pittman, Kara B., Charles W. Cahoon, Kevin W. Bamber, Lucas S. Rector e Michael L. Flessner. "Herbicide selection to terminate grass, legume, and brassica cover crop species". Weed Technology 34, n. 1 (18 novembre 2019): 48–54. http://dx.doi.org/10.1017/wet.2019.107.
Testo completoAbstract (sommario):
AbstractCover crops provide a number of agronomic benefits, including weed suppression, which is important as cases of herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass is needed, which necessitates later termination timing. Cover crop termination is important to mitigate potential planting issues and prevent surviving cover crop competition with cash crops. Field studies were conducted in Virginia to determine the most effective herbicide options alone or combined with glyphosate or paraquat to terminate a range of cover crop species. Results revealed that grass cover crop species were controlled (94% to 98%) by glyphosate alone 4 wk after application (WAA). Overall, legume species varied in response to the single active-ingredient treatments, and control increased with the addition of glyphosate or paraquat. Mixes with glyphosate provided better control of crimson clover and hairy vetch by 7% to 8% compared with mixes containing paraquat 4 WAA. Mix partner did not influence control of Austrian winter pea. No treatment adequately controlled rapeseed in this study, with a maximum of 58% control observed with single active-ingredient treatments and 62% control with mixes. Height reduction for all cover crop species supports visible rating data. Rapeseed should be terminated when smaller, which could negate weed suppressive benefits from this cover crop species. Growers should consider herbicide selection and termination timing in their cover crop plan to ensure effective termination.
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Whalen, Derek M., Mandy D. Bish, Bryan G. Young, Shawn P. Conley, Daniel B. Reynolds, Jason K. Norsworthy e Kevin W. Bradley. "Herbicide programs for the termination of grass and broadleaf cover crop species". Weed Technology 34, n. 1 (9 settembre 2019): 1–10. http://dx.doi.org/10.1017/wet.2019.73.
Testo completoAbstract (sommario):
AbstractThe use of cover crops in soybean production systems has increased in recent years. There are many questions surrounding cover crops—specifically about benefits to crop production and most effective herbicides for spring termination. No studies evaluating cover crop termination have been conducted across a wide geographic area, to our knowledge. Therefore, field experiments were conducted in 2016 and 2017 in Arkansas, Indiana, Mississippi, Missouri, and Wisconsin for spring termination of regionally specific cover crops. Glyphosate-, glufosinate-, and paraquat-containing treatments were applied between April 15 and April 29 in 2016 and April 10 and April 20 in 2017. Visible control of cover crops was determined 28 days after treatment. Glyphosate-containing herbicide treatments were more effective than paraquat- and glufosinate-containing treatments, providing 71% to 97% control across all site years. Specifically, glyphosate at 1.12 kg ha−1 applied alone or with 2,4-D at 0.56 kg ha−1, saflufenacil at 0.025 kg ha−1, or clethodim at 0.56 kg ha−1 provided the most effective control on all grass cover crop species. Glyphosate-, paraquat-, or glufosinate-containing treatments were generally most effective on broadleaf cover crop species when applied with 2,4-D or dicamba. Results from this research indicate that proper herbicide selection is crucial to successfully terminate cover crops in the spring.
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Wortman, Sam E., Charles A. Francis, Mark A. Bernards, Erin E. Blankenship e John L. Lindquist. "Mechanical Termination of Diverse Cover Crop Mixtures for Improved Weed Suppression in Organic Cropping Systems". Weed Science 61, n. 1 (marzo 2013): 162–70. http://dx.doi.org/10.1614/ws-d-12-00066.1.
Testo completoAbstract (sommario):
Cover crops can provide many benefits in agroecosystems, including the opportunity for improved weed control. However, the weed suppressive potential of cover crops may depend on the species (or mixture of species) chosen, and the method of cover crop termination and residue management. The objective of this study was to determine the effects of cover crop mixture and mechanical termination method on weed biomass and density, and relative crop yield in an organic cropping system. A field experiment was conducted from 2009 to 2011 near Mead, NE, where spring-sown mixtures of two, four, six, and eight cover crop species were included in a sunflower–soybean–corn crop rotation. Cover crops were planted in late March, terminated in late May using a field disk or sweep plow undercutter, and main crops were planted within 1 wk of termination. Terminating cover crops with the undercutter consistently reduced early-season grass weed biomass, whereas termination with the field disk typically stimulated grass weed biomass relative to a no cover crop control (NC). The effects of cover crop mixture were not evident in 2009, but the combination of the undercutter and the eight-species mixture reduced early-season weed biomass by 48% relative to the NC treatment in 2010. Cover crops provided less weed control in 2011, where only the combination of the undercutter and the two-species mixture reduced weed biomass (by 31%) relative to the NC treatment. Termination with the undercutter resulted in relative yield increases of 16.6 and 22.7% in corn and soybean, respectively. In contrast, termination with the field disk resulted in a relative yield reduction of 13.6% in soybean. The dominant influence of termination method highlights the importance of appropriate cover crop residue management in maximizing potential agronomic benefits associated with cover crops.
16
Murrell, Ebony G., Swayamjit Ray, Mary E. Lemmon, Dawn S. Luthe e Jason P. Kaye. "Cover crop species affect mycorrhizae-mediated nutrient uptake and pest resistance in maize". Renewable Agriculture and Food Systems 35, n. 5 (18 febbraio 2019): 467–74. http://dx.doi.org/10.1017/s1742170519000061.
Testo completoAbstract (sommario):
AbstractArbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.
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Carabajal-Capitán, Sara, Andrew R. Kniss e Randa Jabbour. "Seed Predation of Interseeded Cover Crops and Resulting Impacts on Ground Beetles". Environmental Entomology 50, n. 4 (12 aprile 2021): 832–41. http://dx.doi.org/10.1093/ee/nvab026.
Testo completoAbstract (sommario):
Abstract Interseeding cover crops into standing grains can promote both agronomic and environmental benefits within agroecosystems. Producers must decide which cover crops are the best fit for their goals, and whether diverse cover crop mixtures provide benefits that are worth the increased seed cost. Broadcast seeding is an accessible strategy to try interseeding but can lead to patchy establishment; it is unknown how much seed loss is due to seed predators. In a two-year study, six cover crop species—planted as either single species or mixtures—were interseeded into standing corn. We evaluated seed predation at the time of seeding, agronomic impact through cover crop, and weedy biomass at the end of the season, and conservation impact through activity-density of ground beetles (Coleoptera: Carabidae). Cover crop seeds were vulnerable to seed predation, primarily by vertebrate seed predators, and seed loss varied across cover crop species. Cover crop biomass did not differ according to cover crop diversity and weedy biomass was not affected by cover crop presence or species. Cover crop diversity effects on carabid activity-density were inconsistent: carabids were higher in diverse mixtures in 1 year of the study, but only predicted by vegetative cover, not by cover crop, in the second year. Interseeding cover crops into corn has potential benefits for ground beetles, although the value of mixtures must be further explored.
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RAMIREZ-GARCIA, J., J. L. GABRIEL, M. ALONSO-AYUSO e M. QUEMADA. "Quantitative characterization of five cover crop species". Journal of Agricultural Science 153, n. 7 (2 settembre 2014): 1174–85. http://dx.doi.org/10.1017/s0021859614000811.
Testo completoAbstract (sommario):
SUMMARYThe introduction of cover crops in the intercrop period may provide a broad range of ecosystem services derived from the multiple functions they can perform, such as erosion control, recycling of nutrients or forage source. However, the achievement of these services in a particular agrosystem is not always required at the same time or to the same degree. Thus, species selection and definition of targeted objectives is critical when growing cover crops. The goal of the current work was to describe the traits that determine the suitability of five species (barley, rye, triticale, mustard and vetch) for cover cropping. A field trial was established during two seasons (October to April) in Madrid (central Spain). Ground cover and biomass were monitored at regular intervals during each growing season. A Gompertz model characterized ground cover until the decay observed after frosts, while biomass was fitted to Gompertz, logistic and linear-exponential equations. At the end of the experiment, carbon (C), nitrogen (N), and fibre (neutral detergent, acid and lignin) contents, and the N fixed by the legume were determined. The grasses reached the highest ground cover (83–99%) and biomass (1226–1928 g/m2) at the end of the experiment. With the highest C:N ratio (27–39) and dietary fibre (527–600 mg/g) and the lowest residue quality (~680 mg/g), grasses were suitable for erosion control, catch crop and fodder. The vetch presented the lowest N uptake (2·4 and 0·7 g N/m2) due to N fixation (9·8 and 1·6 g N/m2) and low biomass accumulation. The mustard presented high N uptake in the warm year and could act as a catch crop, but low fodder capability in both years. The thermal time before reaching 30% ground cover was a good indicator of early coverage species. Variable quantification allowed finding variability among the species and provided information for further decisions involving cover crop selection and management.
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Blackshaw, R. E., e C. W. Lindwall. "Species, herbicide and tillage effects on surface crop residue cover during fallow". Canadian Journal of Soil Science 75, n. 4 (1 novembre 1995): 559–65. http://dx.doi.org/10.4141/cjss95-079.
Testo completoAbstract (sommario):
Fallow continues to be a common agronomic practice on the Canadian prairies but it has been associated with increased soil erosion. Risk of fallow erosion can be reduced by maintaining adequate levels of crop residue on the soil surface. Field experiments were conducted at Lethbridge, Alberta from 1991 to 1993 to determine if commonly grown prairie crops differ in their rates of crop residue degradation during fallow and to assess the effect of herbicides and wide-blade tillage on loss of crop residues. The ranking of crop residue losses during fallow was lentil > canola > rye > barley > wheat > flax. High N content in residues usually increased the rate of biomass loss. Flax straw, perhaps because of its high lignin content, did not follow this pattern and was the most persistent of all crop residues. Up to three applications of the herbicides, glyphosate, paraquat, and 2,4-D, at recommended rates did not alter field degradation of any of these crops. These herbicides maintained greater amounts of anchored and total surface crop residues than wide-blade tillage during both fallow seasons. Results are discussed in terms of crops grown before fallow, weed control during fallow, and maintenance of sufficient surface plant residues to reduce the risk of soil erosion. Key words: Glyphosate, paraquat, 2,4-D, reduced tillage, soil erosion, stubble retention
20
Disi, Onwusemu. "Understanding epigenetic effects in crop species". African Journal of Plant Science 6, n. 14 (30 novembre 2012): 355–63. http://dx.doi.org/10.5897/ajps11.099.
Testo completo
21
Carrari, Fernando, Ewa Urbanczyk-Wochniak, Lothar Willmitzer e Alisdair R. Fernie. "Engineering central metabolism in crop species:". Metabolic Engineering 5, n. 3 (luglio 2003): 191–200. http://dx.doi.org/10.1016/s1096-7176(03)00028-4.
Testo completo
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Jung, C. "Engineering nematode resistance in crop species". Trends in Plant Science 3, n. 7 (1 luglio 1998): 266–71. http://dx.doi.org/10.1016/s1360-1385(98)01247-3.
Testo completo
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., Anandkumar Patil. "CROP SPECIES IDENTIFICATION USING NN TOOL". International Journal of Research in Engineering and Technology 04, n. 17 (25 maggio 2015): 100–105. http://dx.doi.org/10.15623/ijret.2015.0417023.
Testo completo
24
Canner, Stephen R., L. J. Wiles, Robert H. Erskine, Gregory S. McMaster, Gale H. Dunn e James C. Ascough. "Modeling With Limited Data: The Influence of Crop Rotation and Management on Weed Communities and Crop Yield Loss". Weed Science 57, n. 2 (aprile 2009): 175–86. http://dx.doi.org/10.1614/ws-08-036.1.
Testo completoAbstract (sommario):
Theory and models of crop yield loss from weed competition have led to decision models to help growers choose cost-effective weed management. These models are available for multiple-species weed communities in a single season of several crops. Growers also rely on crop rotation for weed control, yet theory and models of weed population dynamics have not led to similar tools for planning of crop rotations for cost-effective weed management. Obstacles have been the complexity of modeling the dynamics of multiple populations of weed species compared to a single species and lack of data. We developed a method to use limited, readily observed data to simulate population dynamics and crop yield loss of multiple-species weed communities in response to crop rotation, tillage system, and specific weed management tactics. Our method is based on the general theory of density dependence of plant productivity and extensive use of rectangular hyperbolic equations for describing crop yield loss as a function of weed density. Only two density-independent parameters are required for each species to represent differences in seed bank mortality, emergence, and maximum seed production. One equation is used to model crop yield loss and density-dependent weed seed production as a function of crop and weed density, relative time of weed and crop emergence, and differences among species in competitive ability. The model has been parameterized for six crops and 15 weeds, and limited evaluation indicates predictions are accurate enough to highlight potential weed problems and solutions when comparing alternative crop rotations for a field. The model has been incorporated into a decision support tool for whole-farm management so growers in the Central Great Plains of the United States can compare alternative crop rotations and how their choice influences farm income, herbicide use, and control of weeds in their fields.
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Baraibar, Barbara, Mitchell C. Hunter, Meagan E. Schipanski, Abbe Hamilton e David A. Mortensen. "Weed Suppression in Cover Crop Monocultures and Mixtures". Weed Science 66, n. 1 (2 ottobre 2017): 121–33. http://dx.doi.org/10.1017/wsc.2017.59.
Testo completoAbstract (sommario):
Interest in planting mixtures of cover crop species has grown in recent years as farmers seek to increase the breadth of ecosystem services cover crops provide. As part of a multidisciplinary project, we quantified the degree to which monocultures and mixtures of cover crops suppress weeds during the fall-to-spring cover crop growing period. Weed-suppressive cover crop stands can limit weed seed rain from summer- and winter-annual species, reducing weed population growth and ultimately weed pressure in future cash crop stands. We established monocultures and mixtures of two legumes (medium red clover and Austrian winter pea), two grasses (cereal rye and oats), and two brassicas (forage radish and canola) in a long fall growing window following winter wheat harvest and in a shorter window following silage corn harvest. In fall of the long window, grass cover crops and mixtures were the most weed suppressive, whereas legume cover crops were the least weed suppressive. All mixtures also effectively suppressed weeds. This was likely primarily due to the presence of fast-growing grass species, which were effective even when they were seeded at only 20% of their monoculture rate. In spring, weed biomass was low in all treatments due to winter kill of summer-annual weeds and low germination of winter annuals. In the short window following silage corn, biomass accumulation by cover crops and weeds in the fall was more than an order of magnitude lower than in the longer window. However, there was substantial weed seed production in the spring in all treatments not containing cereal rye (monoculture or mixture). Our results suggest that cover crop mixtures require only low seeding rates of aggressive grass species to provide weed suppression. This creates an opportunity for other species to deliver additional ecosystem services, though careful species selection may be required to maintain mixture diversity and avoid dominance of winter-hardy cover crop grasses in the spring.
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Kharel, Tulsi P., Ammar B. Bhandari, Partson Mubvumba, Heather L. Tyler, Reginald S. Fletcher e Krishna N. Reddy. "Mixed-Species Cover Crop Biomass Estimation Using Planet Imagery". Sensors 23, n. 3 (31 gennaio 2023): 1541. http://dx.doi.org/10.3390/s23031541.
Testo completoAbstract (sommario):
Cover crop biomass is helpful for weed and pest control, soil erosion control, nutrient recycling, and overall soil health and crop productivity improvement. These benefits may vary based on cover crop species and their biomass. There is growing interest in the agricultural sector of using remotely sensed imagery to estimate cover crop biomass. Four small plot study sites located at the United States Department of Agriculture Agricultural Research Service, Crop Production Systems Research Unit farm, Stoneville, MS with different cereals, legumes, and their mixture as fall-seeded cover crops were selected for this analysis. A randomized complete block design with four replications was used at all four study sites. Cover crop biomass and canopy-level hyperspectral data were collected at the end of April, just before cover crop termination. High-resolution (3 m) PlanetScope imagery (Dove satellite constellation with PS2.SD and PSB.SD sensors) was collected throughout the cover crop season from November to April in the 2021 and 2022 study cycles. Results showed that mixed cover crop increased biomass production up to 24% higher compared to single species rye. Reflectance bands (blue, green, red and near infrared) and vegetation indices derived from imagery collected during March were more strongly correlated with biomass (r = 0–0.74) compared to imagery from November (r = 0.01–0.41) and April (r = 0.03–0.57), suggesting that the timing of imagery acquisition is important for biomass estimation. The highest correlation was observed with the near-infrared band (r = 0.74) during March. The R2 for biomass prediction with the random forest model improved from 0.25 to 0.61 when cover crop species/mix information was added along with Planet imagery bands and vegetation indices as biomass predictors. More study with multiple timepoint biomass, hyperspectral, and imagery collection is needed to choose appropriate bands and estimate the biomass of mix cover crop species.
27
Petereit, Jakob, Philipp E. Bayer, William J. W. Thomas, Cassandria G. Tay Fernandez, Junrey Amas, Yueqi Zhang, Jacqueline Batley e David Edwards. "Pangenomics and Crop Genome Adaptation in a Changing Climate". Plants 11, n. 15 (27 luglio 2022): 1949. http://dx.doi.org/10.3390/plants11151949.
Testo completoAbstract (sommario):
During crop domestication and breeding, wild plant species have been shaped into modern high-yield crops and adapted to the main agro-ecological regions. However, climate change will impact crop productivity in these regions, and agriculture needs to adapt to support future food production. On a global scale, crop wild relatives grow in more diverse environments than crop species, and so may host genes that could support the adaptation of crops to new and variable environments. Through identification of individuals with increased climate resilience we may gain a greater understanding of the genomic basis for this resilience and transfer this to crops. Pangenome analysis can help to identify the genes underlying stress responses in individuals harbouring untapped genomic diversity in crop wild relatives. The information gained from the analysis of these pangenomes can then be applied towards breeding climate resilience into existing crops or to re-domesticating crops, combining environmental adaptation traits with crop productivity.
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Hutianskyi, R., S. Popov, V. Zuza e N. Kuzmenko. "Dependence of soybean weed infestation on growing conditions in the Eastern Forest-Steppe of Ukraine". Karantin i zahist roslin, n. 2 (27 maggio 2021): 36–41. http://dx.doi.org/10.36495/2312-0614.2021.2.36-41.
Testo completoAbstract (sommario):
Goal. To establish the species composition of weeds, their dominant role and determine the type and level of weediness of soybean crops for cultivation in a fixed nine-course stationary, fallow-crop-row rotation and in monoculture in the eastern part of the Forest-Steppe of Ukraine.
Methods. The research was conducted by route surveys in field experiments.
Results. According to the research of 2011—2017, 30 species of weeds and contaminants were found in soybean crops after winter wheat as forecrop in the stationary crop rotation (spring early and late were 60%, winter and biennial were 17%, perennial were 23%), and 18 species (spring early and late were 72%, wintering and biennial were 6%, perennial were 22%) were found for cultivation in monoculture. They belonged to 16 families, the families Asteraceae (9 species), Poaceae (5 species) and Polygonaceae (5 species) were the most represented. The main weeds in soybean crops in crop rotation and monoculture were Echinochloa crus-galli (L.) Roem. et Schult., Chenopodium album L., Cirsium arvense (L.) Scop. and Panicum miliaceum L. In addition to these weeds for growing soybeans in crop rotation were present Setaria glauca (L.) Beauv., Amaranthus retroflexus L., Solanum nigrum L., Polygonum lapathifolium L., Sonchus arvensis L., Convolvulus arvensis L., and in monoculture were Ambrosia artemisiifolia L. and Xanthium strumarium L. Xanthium strumarium L. was the most dominant in the monoculture (43%), and Setaria glauca (L.) Beauv was subdominant in crop rotation (57%), and Echinochloa crus-galli (L.) Roem. and Schult. was subdominant in monoculture (57%). Six complex types of weeds were formed in soybean crops, cereal-dicotyledonous-dicotyledonous-root-sprouting and dicotyledonous-grass-annual-grass-root-sprouting prevailed. For cultivation in crop rotation cereal annual species predominated, and dicotyledonous annuals predominated in monoculture. At the same time, the monoculture had a higher level of weeding than crop rotation, or it was equivalent.
Conclusions. The species composition of weeds in soybean crops in fallow-crop-row rotation and monoculture differs significantly, which should be taken into account by the agronomic service of farms when developing methods of their control.
29
Tay Fernandez, Cassandria Geraldine, Benjamin John Nestor, Monica Furaste Danilevicz, Mitchell Gill, Jakob Petereit, Philipp Emanuel Bayer, Patrick Michael Finnegan, Jacqueline Batley e David Edwards. "Pangenomes as a Resource to Accelerate Breeding of Under-Utilised Crop Species". International Journal of Molecular Sciences 23, n. 5 (28 febbraio 2022): 2671. http://dx.doi.org/10.3390/ijms23052671.
Testo completoAbstract (sommario):
Pangenomes are a rich resource to examine the genomic variation observed within a species or genera, supporting population genetics studies, with applications for the improvement of crop traits. Major crop species such as maize (Zea mays), rice (Oryza sativa), Brassica (Brassica spp.), and soybean (Glycine max) have had pangenomes constructed and released, and this has led to the discovery of valuable genes associated with disease resistance and yield components. However, pangenome data are not available for many less prominent crop species that are currently under-utilised. Despite many under-utilised species being important food sources in regional populations, the scarcity of genomic data for these species hinders their improvement. Here, we assess several under-utilised crops and review the pangenome approaches that could be used to build resources for their improvement. Many of these under-utilised crops are cultivated in arid or semi-arid environments, suggesting that novel genes related to drought tolerance may be identified and used for introgression into related major crop species. In addition, we discuss how previously collected data could be used to enrich pangenome functional analysis in genome-wide association studies (GWAS) based on studies in major crops. Considering the technological advances in genome sequencing, pangenome references for under-utilised species are becoming more obtainable, offering the opportunity to identify novel genes related to agro-morphological traits in these species.
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Aramburu Merlos, Fernando, e Robert J. Hijmans. "The scale dependency of spatial crop species diversity and its relation to temporal diversity". Proceedings of the National Academy of Sciences 117, n. 42 (5 ottobre 2020): 26176–82. http://dx.doi.org/10.1073/pnas.2011702117.
Testo completoAbstract (sommario):
Increasing crop species diversity can enhance agricultural sustainability, but the scale dependency of the processes that shape diversity and of the effects of diversity on agroecosystems is insufficiently understood. We used 30 m spatial resolution crop classification data for the conterminous United States to analyze spatial and temporal crop species diversity and their relationship. We found that the US average temporal (crop rotation) diversity is 2.1 effective number of species and that a crop’s average temporal diversity is lowest for common crops. Spatial diversity monotonically increases with the size of the unit of observation, and it is most strongly associated with temporal diversity when measured for areas of 100 to 400 ha, which is the typical US farm size. The association between diversity in space and time weakens as data are aggregated over larger areas because of the increasing diversity among farms, but at intermediate aggregation levels (counties) it is possible to estimate temporal diversity and farm-scale spatial diversity from aggregated spatial crop diversity data if the effect of beta diversity is considered. For larger areas, the diversity among farms is usually much greater than the diversity within them, and this needs to be considered when analyzing large-area crop diversity data. US agriculture is dominated by a few major annual crops (maize, soybean, wheat) that are mostly grown on fields with a very low temporal diversity. To increase crop species diversity, currently minor crops would have to increase in area at the expense of these major crops.
31
Petit, Johann, Cécile Bres, Jean-Philippe Mauxion, Bénédicte Bakan e Christophe Rothan. "Breeding for cuticle-associated traits in crop species: traits, targets, and strategies". Journal of Experimental Botany 68, n. 19 (27 settembre 2017): 5369–87. http://dx.doi.org/10.1093/jxb/erx341.
Testo completoAbstract (sommario):
Abstract Improving crop productivity and quality while promoting sustainable agriculture have become major goals in plant breeding. The cuticle is a natural film covering the aerial organs of plants and consists of lipid polyesters covered and embedded with wax. The cuticle protects plants against water loss and pathogens and affects traits with strong impacts on crop quality such as, for horticultural crops, fruit brightness, cracking, russeting, netting, and shelf life. Here we provide an overview of the most important cuticle-associated traits that can be targeted for crop improvement. To date, most studies on cuticle-associated traits aimed at crop breeding have been done on fleshy fruits. Less information is available for staple crops such as rice, wheat or maize. Here we present new insights into cuticle formation and properties resulting from the study of genetic resources available for the various crop species. Our review also covers the current strategies and tools aimed at exploiting available natural and artificially induced genetic diversity and the technologies used to transfer the beneficial alleles affecting cuticle-associated traits to commercial varieties.
32
Toom, Merili, Sirje Tamm, Liina Talgre, Ilmar Tamm, Ülle Tamm, Lea Narits, Inga Hiiesalu, Andres Mäe e Enn Lauringson. "The Effect of Cover Crops on the Yield of Spring Barley in Estonia". Agriculture 9, n. 8 (3 agosto 2019): 172. http://dx.doi.org/10.3390/agriculture9080172.
Testo completoAbstract (sommario):
Using cover crops in fallow periods of crop production is an important management tool for reducing nitrate leaching and therefore improving nitrogen availability for subsequent crops. We estimated the short-term effect of five cover crop species on the yield of successive spring barley (Hordeum vulgare L.) for two years in Estonia. The cover crop species used in the study were winter rye (Secale cereale L.), winter turnip rape (Brassica rapa spp. oleifera L.), forage radish (Raphanus sativus L. var. longipinnatus), hairy vetch (Vicia villosa Roth), and berseem clover (Trifolium alexandrinum L.). The results indicated that out of the five tested cover crops, forage radish and hairy vetch increased the yield of subsequent spring barley, whereas the other cover crops had no effect on barley yield. All cover crop species had low C:N ratios (11–17), suggesting that nitrogen (N) was available for barley early in the spring.
33
Bissessur, P., C. Baider, N. Boodia, M. G. H. Badaloo, J. A. Bégué, Z. Jhumka, A. Meunier et al. "Crop wild relative diversity and conservation planning in two isolated oceanic islands of a biodiversity hotspot (Mauritius and Rodrigues)". Plant Genetic Resources: Characterization and Utilization 17, n. 2 (26 gennaio 2019): 174–84. http://dx.doi.org/10.1017/s1479262118000576.
Testo completoAbstract (sommario):
AbstractThe rising need for crop diversification to mitigate the impacts of climate change on food security urges the exploration of crop wild relatives (CWR) as potential genetic resources for crop improvement. This study aimed at assessing the diversity of CWR of the Indian Ocean islands of Mauritius and Rodrigues and proposing cost-effective conservation measures for their sustainable use. A comprehensive list of the native species was collated from The Mauritius Herbarium and published literature. Each species was assessed for the economic value of its related crop, utilization potential for crop improvement, relative distribution, occurrence status and Red List conservation status, using a standard scoring method for prioritization. The occurrence data of the priority species were collected, verified, geo-referenced and mapped. A total of 43 crop-related species were identified for both islands and 21 species were prioritized for active conservation. The CWR diversity hotspots in Mauritius included Mondrain, followed by Florin and Le Pouce Mountain. Although a wide diversity of CWR has been recorded on both islands, most do not relate to major economic crops in use, therefore only a few species may be gene donors to economic crops at the regional and global level. For example, coffee, a major global beverage crop, has three wild relatives on Mauritius, which could potentially be of interest for future predictive characterization.
34
Bybee-Finley, K. Ann, Steven B. Mirsky e Matthew R. Ryan. "Crop Biomass Not Species Richness Drives Weed Suppression in Warm-Season Annual Grass–Legume Intercrops in the Northeast". Weed Science 65, n. 5 (24 luglio 2017): 669–80. http://dx.doi.org/10.1017/wsc.2017.25.
Testo completoAbstract (sommario):
Intercropping with functionally diverse crops can reduce the availability of resources that could otherwise be used by weeds. An experiment was conducted across 6 site-years in New York and Maryland in 2013 and 2014 to examine the effects of functional diversity and crop species richness on weed suppression. We compared four annual crop species that differed in stature and nitrogen acquisition traits: (1) pearl millet, (2) sorghum sudangrass, (3) cowpea, and (4) sunn hemp. Crops were seeded in monoculture and in three- and four-species mixtures using a replacement design in which monoculture seeding rates were divided by the number of species in the intercrop. Crop and weed biomass were sampled at ~45 and 90 d after planting. At the first sampling date, intercrops produced more crop biomass than monocultures in all but 1 site-year; however, weed biomass in intercrops was lower than monocultures in only 1 site-year. By the second sampling date, crop biomass was consistently greater in the intercrops than in the monocultures, and weed biomass was lower in the intercrops than in monocultures in 2 site-years. Although we observed several negative relationships between crop species richness and weed biomass, crop biomass was a more important factor than species richness for suppressing weeds. Despite the weak weed suppression from the two legumes compared with the two grasses, legume crops can provide other benefits, including increased forage quality, soil nitrogen for subsequent crops, and resources for pollinators if allowed to flower. On the other hand, if weed suppression is the top priority, our results suggest that monocultures of high biomass–producing grasses will provide more effective suppression at a lower seed cost than functionally diverse intercrops that include low biomass–producing legumes in warm-season intercrops.
35
Angus, J. F., J. A. Kirkegaard, J. R. Hunt, M. H. Ryan, L. Ohlander e M. B. Peoples. "Break crops and rotations for wheat". Crop and Pasture Science 66, n. 6 (2015): 523. http://dx.doi.org/10.1071/cp14252.
Testo completoAbstract (sommario):
Wheat crops usually yield more when grown after another species than when grown after wheat. Quantifying the yield increase and explaining the factors that affect the increase will assist farmers to decide on crop sequences. This review quantifies the yield increase, based on >900 comparisons of wheat growing after a break crop with wheat after wheat. The mean increase in wheat yield varied with species of break crop, ranging from 0.5 t ha–1 after oats to 1.2 t ha–1 after grain legumes. Based on overlapping experiments, the observed ranking of break-crop species in terms of mean yield response of the following wheat crop was: oats < canola ≈ mustard ≈ flax < field peas ≈ faba beans ≈ chickpeas ≈ lentils ≈ lupins. The mean additional wheat yield after oats or oilseed break crops was independent of the yield level of the following wheat crop. The wheat yield response to legume break crops was not clearly independent of yield level and was relatively greater at high yields. The yield of wheat after two successive break crops was 0.1–0.3 t ha–1 greater than after a single break crop. The additional yield of a second wheat crop after a single break crop ranged from 20% of the effect on a first wheat crop after canola, to 60% after legumes. The mean yield effect on a third wheat crop was negligible, except in persistently dry conditions. The variability of the break-crop effect on the yield of a second wheat crop was larger than of a first wheat crop, particularly following canola. We discuss the responses in relation to mechanisms by which break crops affect soil and following crops. By quantifying the magnitude and persistence of break-crop effects, we aim to provide a basis for the decision to grow continuous cereal crops, strategic rotations or tactically selected break crops. In many wheat-growing areas, the large potential yield increases due to break crops are not fully exploited. Research into quantifying the net benefits of break crops, determining the situations where the benefits are greatest, and improving the benefits of break crops promises to improve the efficiency of wheat-based cropping systems.
36
Cottney, Paul, Lisa Black, Ethel White e Paul N. Williams. "The Correct Cover Crop Species Integrated with Slurry Can Increase Biomass, Quality and Nitrogen Cycling to Positively Affect Yields in a Subsequent Spring Barley Rotation". Agronomy 10, n. 11 (12 novembre 2020): 1760. http://dx.doi.org/10.3390/agronomy10111760.
Testo completoAbstract (sommario):
The aim of this study is to identify species of cover crops that cause an increase in biomass and total nutrient accumulation in response to manure/slurry. This could improve nutrient efficiency and intensify the benefits from over-winter cover crops in arable rotations and improve following commercial crop yields. In a pot experiment, sixteen cover crops were grown for 100 days in response to slurry. Growth and nutrient (N, P, K, Mg and S) accumulation were measured, and then residue was reincorporated into the soil with spring barley (Hodeum vulgare L.) sown and harvested for yield. In response to slurry, tillage radish (Raphanus sativus L.) increased N accumulation by 101% due to a significant increase in biomass and % N (p < 0.05) over its relative control plots. Significant interactions between species and the application of slurry were found in cover crop biomass, cover crop and spring barley nutrient uptake, as well as cover crop carbon accumulation, particularly in the brassica species used. Slurry integrated with cover crops both reduced the cover crop C:N ratio and enhanced nutrient cycling compared to the control when soil mineral nitrogen (SMN) and spring barley crop N offtake were pooled. However, this was not observed in the legumes. This study shows that slurry integration with cover crops is a promising sustainable farming practice to sequester N and other macro-nutrients whilst providing a range of synergistic benefits to spring barley production when compared to unplanted/fallow land rotations. However, this advantage is subject to use of responsive cover crop species identified in this study.
37
Lima, Gislaine Piccolo de, Lúcia Helena Pereira Nóbrega, Márcia Maria Mauli, Danielle Medina Rosa e Adriana Smanhotto. "Soybean growth and yield after single tillage and species mixture of cover plants". Revista Ceres 59, n. 5 (ottobre 2012): 695–700. http://dx.doi.org/10.1590/s0034-737x2012000500016.
Testo completoAbstract (sommario):
The use of cover crops is important for the agricultural crop and soil management in order to improve the system and, consequently, to increase yield. Therefore, the present study analyzed the effect of crop residues of black oat (Avena strigosa Schreb.) (BO) and a cocktail (CO) of BO, forage turnip (Raphanus sativus L.) (FT) and common vetch (Vicia sativa L.) (V) on the emergence speed index (ESI), seedling emergence speed (SES) plant height and soybean yield in different intervals between cover crop desiccation with glyphosate 480 (3 L ha-1) and BRS 232 cultivar sowing. Plots of 5 x 2.5 m with 1 m of border received four treatments with BO cover crops and four with CO as well as a control for each cover crop, at random, with five replications. The plots were desiccated in intervals of 1, 10, 20 and 30 days before soybean seeding. The harvest was manual while yield was adjusted to 13% of moisture content. The experimental design was completely randomized with splitplots and means compared by the Scott and Knott test at 5% of significance. The results showed that CO of cover crops can be recommended for soybean to obtain a more vigorous seedling emergence, from 10 days after cover crop desiccation.
38
Sudiana, Eming, Edy Yani, Lucky Prayoga, Darsono Darsono, Edy Riwidiharso e Slamet Santoso. "Adaptations of Three Cash Crops to Climate Change". Biosaintifika: Journal of Biology & Biology Education 12, n. 2 (8 agosto 2020): 247–53. http://dx.doi.org/10.15294/biosaintifika.v12i2.23489.
Testo completoAbstract (sommario):
Climate change is likely to lead to adaptations among important crop species. Elevational gradients can be used to illustrate the effects of climate change on crop adaptation patterns. The research aimed to determine adaptation patterns in crop species across an elevational (and therefore temperature and humidity) gradient. A factorial design was applied with two factors within a simple Randomized Complete Block Design, wherein the primary factor was elevation (10 – 1,000 m). Three crop species (long bean, common bean, and winged bean) were used as test species. Growth rate and flower number were used as adaptation parameters. The results indicated that these three cash crop species showed different adaptation patterns. Common bean showed the greatest vegetative growth at approximately 600 m in elevation, long bean at 400 m in elevation, and winged bean at 10 m in elevation. The results of this study indicate that the three tested agricultural crops have different adaptation patterns, and these results was the first finding to be published in Indonesia. For agriculture practices, it can be recommended that planting of these cash crops be adapted to the elevation of the planting area.
39
Denton, Savana D., Darrin M. Dodds, L. Jason Krutz, Jac J. Varco, Jeffrey Gore e Tyson B. Raper. "Evaluation of Cover Crop Species Termination Timing Prior to Cotton Production in Mississippi". Journal of Cotton Science 24, n. 3 (2020): 97–103. http://dx.doi.org/10.56454/zcql1443.
Testo completoAbstract (sommario):
The termination timing of cover crops varies by farm. This research was conducted to determine whether the timing of cover crop termination alters cotton growth and development. The effects of cover crop (crimson clover, cereal rye, oat, and a blend of cereal rye + crimson clover) and termination timing (targeted dates 01 February, 01 March, 01 April, and 01 May) on cotton emergence, plant height, nodes above white flower and yield was evaluated near Starkville, MS on a Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) in 2017 and 2018 and near Tribbett, MS on a Dundee silty clay loam (Fine-silty, mixed, active, thermic type Typic Endoqualfs) in 2017. Timing of cover crop termination had a transient effect on cotton emergence. Relative to terminating cover crops in March or April, terminating in February or May decreased cotton emergence at 7 days after planting (DAP) by up to 26%. However, by 14 DAP, cotton stand averaged 74,190 plants/ha and there was no effect of cover crop termination timing on emergence. There were modest interaction effects of cover crop and termination timing on cotton development including plant height, number of nodes, and nodes above white flower. Cotton lint yield did not differ due to cover crop species but increased up to 8% when cover crop termination was delayed from February until May. This research indicates that April and May are the optimal times to terminate a cover crop in a Mississippi cotton production system, provided there is a suitable environment for healthy cotton growth.
40
Leijten, Willeke, Ronald Koes, Ilja Roobeek e Giovanna Frugis. "Translating Flowering Time From Arabidopsis thaliana to Brassicaceae and Asteraceae Crop Species". Plants 7, n. 4 (16 dicembre 2018): 111. http://dx.doi.org/10.3390/plants7040111.
Testo completoAbstract (sommario):
Flowering and seed set are essential for plant species to survive, hence plants need to adapt to highly variable environments to flower in the most favorable conditions. Endogenous cues such as plant age and hormones coordinate with the environmental cues like temperature and day length to determine optimal time for the transition from vegetative to reproductive growth. In a breeding context, controlling flowering time would help to speed up the production of new hybrids and produce high yield throughout the year. The flowering time genetic network is extensively studied in the plant model species Arabidopsis thaliana, however this knowledge is still limited in most crops. This article reviews evidence of conservation and divergence of flowering time regulation in A. thaliana with its related crop species in the Brassicaceae and with more distant vegetable crops within the Asteraceae family. Despite the overall conservation of most flowering time pathways in these families, many genes controlling this trait remain elusive, and the function of most Arabidopsis homologs in these crops are yet to be determined. However, the knowledge gathered so far in both model and crop species can be already exploited in vegetable crop breeding for flowering time control.
41
Wietzke, Alexander, Clara-Sophie van Waveren, Erwin Bergmeier, Stefan Meyer e Christoph Leuschner. "Current State and Drivers of Arable Plant Diversity in Conventionally Managed Farmland in Northwest Germany". Diversity 12, n. 12 (11 dicembre 2020): 469. http://dx.doi.org/10.3390/d12120469.
Testo completoAbstract (sommario):
Agricultural intensification has led to dramatic diversity losses and impoverishment of the arable vegetation in much of Europe. We analyzed the status of farmland phytodiversity and its determinants in 2016 in northwest Germany by surveying 200 conventionally managed fields cultivated with seven crops. The study was combined with an analysis of edaphic (soil yield potential), agronomic (crop cover, fertilizer and herbicide use) and landscape factors (adjacent habitats). In total, we recorded 150 non-crop plant species, many of them nitrophilous generalist species, while species of conservation value were almost completely absent. According to a post-hoc pairwise comparison of the mixed model results, the cultivation of rapeseed positively influenced non-crop plant species richness as compared to winter cereals (wheat, barley, rye and triticale; data pooled), maize or potato. The presence of grassy strips and ditch margins adjacent to fields increased plant richness at field edges presumably through spillover effects. In the field interiors, median values of non-crop plant richness and cover were only 2 species and 0.5% cover across all crops, and at the field edges 11 species and 4% cover. Agricultural intensification has wiped out non-crop plant life nearly completely from conventionally managed farmland, except for a narrow, floristically impoverished field edge strip.
42
Eser, Adnan, Hajnalka Kató, Laura Kempf e Márton Jolánkai. "Water footprint of yield protein content of twelve field crop species on a Hungarian crop site". Agrokémia és Talajtan 68, Supplement (dicembre 2019): 53–60. http://dx.doi.org/10.1556/0088.2019.00041.
Testo completoAbstract (sommario):
Abstract Water availability is one of the major physiological factors influencing plant growth and development. An assessment study has been done at the Szent István University, Gödöllő to evaluate and identify the water footprint of protein yield of field crop species. Twelve field crop species (Sugar beet Beta vulgaris, spring and winter barley Hordeum vulgare, winter wheat Triticum aestivum, maize Zea mays, sunflower Helianthus annuus, peas Pisum sativum, potato Solanum tuberosum, alfalfa Medicago sativa, oilseed rape Brassica napus, rye Secale cereale and oats Avena sativa) were involved in the study. Evapotranspiration patterns of the crops studied have been identified by the regular agroclimatology methodology and physiologically reliable protein ranges within crop yields were evaluated. The results obtained suggest, that water footprint of cereals proved to be the lowest, however maize values were highly affected by the high variability of protein yield. Oilseed crops had considerably high protein yield with medium water efficiency. Alfalfa, potato and sugar beet water footprints were in accordance with their evapotranspiration patterns. Protein based water footprint assessment seems to be more applicable in crop species evaluations than that of yield based methodologies.
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Sheldon, Kendall, Sam Purdom, Avat Shekoofa, Larry Steckel e Virginia Sykes. "Allelopathic Impact of Cover Crop Species on Soybean and Goosegrass Seedling Germination and Early Growth". Agriculture 11, n. 10 (3 ottobre 2021): 965. http://dx.doi.org/10.3390/agriculture11100965.
Testo completoAbstract (sommario):
Cover crops can provide a variety of benefits to an agricultural system: weed suppression, soil quality improvement, and soil water infiltration. Although there is ample research documenting weed suppression from cover crops, the mechanics of the suppression are not implicitly understood. Along with the aforementioned positive attributes, negative allelopathic effects on row crops planted into cover crop systems have been documented. The objective of this study was to evaluate the allelopathic potential of certain cover crop species on soybean (Glycine max L.) and goosegrass (Eleusine indica L.) germination and early seedling growth under controlled environments in petri dish and pot experiments. Leachates from above-ground biomass of five cover crop species, wheat (Triticum aestivum L.), cereal rye (Secale cereale), hairy vetch (Vicia villosa), crimson clover (Trifolium incarnatum L.), and canola (Brassica napus L.), from two locations (East and Middle Tennessee) were extracted and applied at 0 (water) and 50 v/v. In experiment I, both soybean and goosegrass seeds were examined, and, in experiment II, only soybean seeds were examined under the application of cover crop leachates. Most cover crop leachates from both locations significantly reduced the soybean seedling root length (p < 0.01). Overall, the application of canola extract (East Tennessee) suppressed soybean seed germination the most (28%) compared to deionized water. For goosegrass, the wheat cover crop leachate significantly reduced seedling root length (p < 0.01). In experiment II, the soybean root nodulation was significantly increased with the wheat extract treatment compared to deionized water. While the results indicate that the location and environment may change cover crop species allelopathic potential, the wheat cover crop leachate had the most potent allelopathic impact on goosegrass germination and growth; however, had the lowest observed adverse effect on our tested row crop, soybean.
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Mitchell, J. P., T. S. Prather, K. J. Hembree, P. B. Goodell, D. M. May e R. L. Coviello. "Cover Crops for San Joaquin Valley Row Crop Production Systems". HortScience 33, n. 3 (giugno 1998): 494e—494. http://dx.doi.org/10.21273/hortsci.33.3.494e.
Testo completoAbstract (sommario):
There is currently considerable interest in the use of cover crops to improve the productivity and sustainability of agroecosystems in California. Adoption of cover crops into San Joaquin Valley row cropping systems has been slow, however, largely because growth characteristics of potentially suitable cover crop species and mixtures have not been identified for the tight windows of opportunity that exist within the region's intensive rotations, and because of uncertainy about the amount of water required to grow a cover crop. In 1995–96 and 1997–98, we screened 15 potential late-summer and winter cover crop species and mixtures planted monthly from 1 Aug. through 1 Nov. and harvested at 30-day intervals through March. In 1995–96, Sorghum-sudan produced 36,543 lb dry matter/acre and was the highest-producing late-summer species in a December-harvested August planting. Triticale and Merced rye were highest-producing winter species, yielding 19,277 and 10,155 lb dry weight/acre, respectively, during the 5-month period from October to March.
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Andersson, Torsten N., e Per Milberg. "Weed flora and the relative importance of site, crop, crop rotation, and nitrogen". Weed Science 46, n. 1 (febbraio 1998): 30–38. http://dx.doi.org/10.1017/s0043174500090135.
Testo completoAbstract (sommario):
Weed species composition and density were recorded in three identical field experiments established 26 to 30 yr ago in southern Sweden. Each experiment compared three 6-yr crop rotations and four rates of nitrogen application. The rotations differed by having (1) a 2-yr rotational grassland, (2) a 2-yr mixed rotational grassland (legume/grass), or (3) spring wheat followed by fallow. Other crops in the rotations were winter turnip rape, winter wheat, spring oats, and spring barley. Using multivariate analyses, the relative importance of site, crop, crop rotation, and nitrogen application rate on the weed flora was determined. The greatest difference was found between sites, and the second most important factor was crop species. Nitrogen application rate weakly influenced the weed flora, while differences between crop rotations were hardly detectable.
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Fernando, Margaret, e Anil Shrestha. "The Potential of Cover Crops for Weed Management: A Sole Tool or Component of an Integrated Weed Management System?" Plants 12, n. 4 (8 febbraio 2023): 752. http://dx.doi.org/10.3390/plants12040752.
Testo completoAbstract (sommario):
Cover crops are an important component of integrated weed management programs in annual and perennial cropping systems because of their weed suppressive abilities. They influence weed populations using different mechanisms of plant interaction which can be facilitative or suppressive. However, the question often arises if cover crops can be solely relied upon for weed management or not. In this review we have tried to provide examples to answer this question. The most common methods of weed suppression by an actively growing cover crop include competition for limited plant growth resources that result in reduced weed biomass, seed production, and hence reductions in the addition of seeds to the soil seedbank. Cover crop mulches suppress weeds by reducing weed seedling emergence through allelopathic effects or physical effects of shading. However, there is a great degree of variability in the success or failure of cover crops in suppressing weeds that are influenced by the cover crop species, time of planting, cover crop densities and biomass, time of cover crop termination, the cash crop following in the rotation, and the season associated with several climatic variables. Several studies demonstrated that planting date was important to achieve maximum cover crop biomass, and a mixture of cover crop species was better than single cover crop species to achieve good weed suppression. Most of the studies that have demonstrated success in weed suppression have only shown partial success and not total success in weed suppression. Therefore, cover crops as a sole tool may not be sufficient to reduce weeds and need to be supplemented with other weed management tools. Nevertheless, cover crops are an important component of the toolbox for integrated weed management.
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Tyler, Heather L. "Single- versus Double-Species Cover Crop Effects on Soil Health and Yield in Mississippi Soybean Fields". Agronomy 11, n. 11 (18 novembre 2021): 2334. http://dx.doi.org/10.3390/agronomy11112334.
Testo completoAbstract (sommario):
Conservation management practices can improve soil health while minimizing deleterious effects of agriculture on the environment. However, adoption of these practices, particularly cover crops, is not widespread, as they often reduce crop yields compared to traditional management practices. The purpose of the current study was to determine if a two-species cover crop treatment of rye (Secale cereale L.) and crimson clover (Trifolium incarnatum L.) could increase soil health parameters and maximize soybean (Glycine max L.) yield greater than rye only in tilled and no-till Mississippi field soils. Enhanced microbial biomass and organic matter input from cover crops increased the activities of β-glucosidase, cellobiohydrolase, fluorescein diacetate hydrolysis, N-acetylglucosaminidase, and phosphatase in surface soils. Rye plus clover tended to elicit higher activities than rye only in no-till plots. Both cover crop treatments inhibited soybean yield in tilled plots by 11–25%. These results indicate that tillage exacerbates yield inhibition by cover crops in soybean and that double-species cover crop treatments were more consistent in increasing activities linked to nutrient cycling. Further study examining different combinations of cover crops in no-till systems is necessary to gain a better understanding of how they can be implemented to enhance soil health while maximizing crop yield.
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Chinedum A Ogazie, Ikechukwu O Agbagwa e Edache B Ochekwu. "Farming system practices on weeds in arable farmlands in University of Port Harcourt and environs, Rivers State-Nigeria". World Journal of Advanced Research and Reviews 14, n. 2 (30 maggio 2022): 031–43. http://dx.doi.org/10.30574/wjarr.2022.14.2.0360.
Testo completoAbstract (sommario):
Crop production involves the combination of various farming systems practices to produce food and cash crops and at the same time have a reasonable control over weed infestation without course to soil health. Weeds are part of agroecosystems community and are neighbors to our crops and the soil. The work was aimed to investigate the weeds that are common in the sites chosen. A simple reconnaissance weed enumeration survey was adopted for the twenty-two (22) arable farmlands by walk through the farms within and round the boundaries. This was investigated between June 2020 as wet season and in January, 2021 as dry season respectively. A total of 154 weed species were recorded for both wet and dry seasons. The wet and dry seasons had 113 and 120 weed species made up of 37 and 36 families respectively. It revealed 168 broad leaved, 32 grasses and 26 sedges, composed of annual and perennial weed species. All the farms were continuously cultivated and mixed cropped, with 27 crop species identified and recorded. The farmers most preferred crops are Manihot esculenta Crantz being a tuberous crop and Zea mays L., grain cereal with 90.91% each from the overall percentage of individual crop species recorded from farmers who planted them on their farmland (Table 1) respectively, and been staple food items in most part of Nigeria, while the least cropped species are (Amaranthus hybridus L., and Solanum lycopersicon L., Ocimum. americanum L., and Solanum sp.) with 4.54% each respectively which are vegetables to supplement peoples ‘diet. Farming systems methods has a tremendous influence on weed species composition in arable farmlands either during the cropping season (wet) or off the season (dry). Some activities are very peculiar within crop production for example bush clearing, and burn, soil tillage in any form or pattern and weed removal either culturally, biological or chemically due impact on weed species in arable farmlands in short or long term and therefore, its impact on crop species and the environment should be minimized and sustained.
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Crosby, Christine, Hector Valenzuela, Bernard Kratky e Carl Evensen. "008 Evaluation of Weed Control in a No-tillage Vegetable Production System". HortScience 34, n. 3 (giugno 1999): 442B—442. http://dx.doi.org/10.21273/hortsci.34.3.442b.
Testo completoAbstract (sommario):
In the tropics, weed control is a year-round concern. The use of cover crops in a conservation tillage system allows for the production of a crop biomass that can be killed and mowed, and later used as mulching material to help reduce weed growth. This study compared yields of three vegetable species grown in two conventional tillage systems, one weeded and one unweeded control, and in two no-tillage treatments using two different cover crop species, oats (Avena sativa L. `Cauyse') and rye grain (Secale cereale L.). The cover crops were seeded (112 kg/ha) in Spring 1998 in 4 × 23-m plots in a RCB design with six replications per treatment, and mowed down at the flowering stage before transplanting the seedlings. Data collection throughout the experimental period included quadrant weed counts, biomass levels, and crop marketable yields. Weed suppression was compared with the yields of the vegetable crops. The greatest vegetable yields were in the conventionally hand-weeded control and the worst in the un-weeded controls. Weed species composition varied depending on the cover crop species treatment. The rye better suppressed weed growth than the oats, with greater control of grass species. Rye, however, suppressed romaine and bell pepper yields more than the oat treatments. Similarly greater eggplant yields and more fruit per plant were found in the oat treatment than in the rye. Both cover crops suppressed weed growth for the first month; however, by the second month most plots had extensive weed growth. This study showed that at the given cover crop seeding rate, the mulch produced was not enough to reduce weed growth and provide acceptable yields of various vegetable crops.
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Terry, Norman, C. Carlson, T. K. Raab e Adel M. Zayed. "Rates of Selenium Volatilization among Crop Species". Journal of Environmental Quality 21, n. 3 (luglio 1992): 341–44. http://dx.doi.org/10.2134/jeq1992.00472425002100030006x.
Testo completo