Planta Daninha最新文献_第8页

Weed Interference in Okra Crop in the Organic System During the Dry Season 旱季杂草对秋葵作物有机系统的干扰

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100014

R. Santos, T. P. Pires, M. Mesquita, M. Corrêa, M.R.S.S Silva

引用次数: 4

Sulfentrazone: Environmental Dynamics and Selectivity 磺胺酮:环境动力学和选择性

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100032

V. R. Gehrke, E. R. Camargo, L. A. Avila

引用次数: 5

Relative Competitiveness Between Cultivated and Weedy Rice under Full and Low Light 栽培稻与杂草稻在全光与弱光条件下的相对竞争力

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100039

C. E. Schaedler, W. Lubian, P. Lima, D. M. Chiapinotto

{"title":"Relative Competitiveness Between Cultivated and Weedy Rice under Full and Low Light","authors":"C. E. Schaedler, W. Lubian, P. Lima, D. M. Chiapinotto","doi":"10.1590/s0100-83582020380100039","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100039","url":null,"abstract":"ABSTRACT: Cultivated and weedy rice biotypes exhibit morphophysiological variations under low light, affecting competition between plants. The aim of this study was to assess relative competitiveness between cultivated and weedy rice under full and low light. Three experiments were conducted in a greenhouse, using a completely randomized design with four repetitions. The treatments in the experiment I were arranged in additive series while in the experiments II and III treatments were arranged in replacement series. Experiments II and III were carried out concomitantly to assess coexistence between the rice cultivar and weedy rice. The treatments consisted of different plants proportions: 100:0 (cultivated rice monoculture), 75:25, 50:50, 25:75 and 0:100 (weedy rice monoculture), keeping the total plant population obtained in experiment I (240 plants m-2) constant. Experiment II was conducted with full solar radiation and III under 50% light. The variables analyzed were shoot dry weight and plant height, 35 days after emergence (DAE). Competition among plants was evaluated via graphs and by interpreting competition indices. Concerning shoot dry weight, mutual losses were recorded between competitors, whereas equal competition for resources was observed for plant height. Weedy rice was more competitive than cultivated rice regardless of the light environment assessed, indicating the need for integrated methods to control this weed.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interference Periods of Weeds in Maize in No-Tillage and Conventional Systems at High Altitudes 高海拔地区免耕与常规体系玉米杂草干扰期研究

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100029

E. O. Helvig, K.K.G. Pinheiro, A. Dranca, A. Silva, M. C. Mendes, C. Maciel

{"title":"Interference Periods of Weeds in Maize in No-Tillage and Conventional Systems at High Altitudes","authors":"E. O. Helvig, K.K.G. Pinheiro, A. Dranca, A. Silva, M. C. Mendes, C. Maciel","doi":"10.1590/s0100-83582020380100029","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100029","url":null,"abstract":"ABSTRACT: The objective of this study was to determine the coexistence periods of weeds (CTWR = critical timing of weed removal) and control (CWFP = critical weed-free period) in maize crops in no-tillage and conventional systems at high altitudes in southern Brazil. To this end, four experiments were conducted in Guarapuava-Paraná during the 2016/2017 crop season using P2530™ (conventional) and P3271H™ (transgenic genetically modified for glyphosate tolerance) hybrids in no-tillage and conventional systems with crop residues of black oat (Avena strigosa). The experimental design was a randomized complete block with five repetitions. The treatments were divided into periods of CTWR and CWFP for 0, 7, 14, 28, 42, 63, and 126 days after the emergence of crops (DAE). Among the weeds, only eudicotyledonous species predominated throughout the crop cycle in both production systems. The productivity results established for P2530™ and P3271H™ hybrids in a conventional system with the incorporation of straw in the soil indicated a critical period of weed control (CPWC) from 23 to 39 DAE and 23 to 35 DAE, respectively. For direct sowing (no-tillage system) on black oat straw, no CPWC was established, as it required only one single point of control between the periods of 21 to 33 DAE and 23 to 31 DAE for the P2530™ and P3271H™ hybrids, respectively. The direct sowing in black oat straw constituted an efficient strategy to reduce weed interference and the necessity of weed management practices.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Redroot pigweed interference with lettuce crop 重根藜草对生菜作物的干扰

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100058

E. Casadei, Allan L. Bacha, Juliana S. Rodrigues, Renata T. S. Santos, Pedro L.C.A. Alves, Arthur B.C. Filho

{"title":"Redroot pigweed interference with lettuce crop","authors":"E. Casadei, Allan L. Bacha, Juliana S. Rodrigues, Renata T. S. Santos, Pedro L.C.A. Alves, Arthur B.C. Filho","doi":"10.1590/s0100-83582020380100058","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100058","url":null,"abstract":"Background: Lettuce-production areas in Brazil are frequently infested by pigweed plants, which can interfere with production by competing for resources or releasing allelopathic compounds in the environment. Objective: The present study evaluated the effect of redroot pigweed (Amaranthus retroflexus) density and distribution on lettuce crop (Lactuca sativa L.). Methods: The cultivars Lídia, Verônica, Lucy Brown and Salad Bowl were used. After transplanting, these plants coexisted until harvest with four pigweed plants (equivalent to 16 plants m-2) located within or outside planting rows, or with one pigweed plant located at the center of the plot (4 plants m-2), as well as a control without weed. The experiment was conducted in an open and semi-controlled area, with treatments arranged in a 4x4 factorial scheme, in a completely randomized experimental design with three replicates. Evaluations included: the number of leaves, fresh matter (lettuce only), height, leaf area and dry matter of lettuce and redroot pigweed plants. Results: The coexistence with redroot pigweed caused yield losses of up to 45% for cultivar Lídia; 41% for Salad Bowl; 33% for Verônica; and 28% for Lucy Brown. Conclusions: The density of 16 plants m-2 of redroot pigweed was the one that most negatively affected the growth of the cultivars, in which the positioning in the planting lines resulted in greater interference to the crop growth. Among the cultivars tested, Lucy Brown showed greater tolerance to coexistence with redroot pigweed plants, while the cultivar Lídia was the most sensitive to the imposed interference.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Weed Interference in Soybean Crop Affects Soil Microbial Activity and Biomass 杂草干扰对大豆作物土壤微生物活性和生物量的影响

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100046

C. Fialho, A. Silva, C. Melo, M. Costa, M. Souza, L. Reis

{"title":"Weed Interference in Soybean Crop Affects Soil Microbial Activity and Biomass","authors":"C. Fialho, A. Silva, C. Melo, M. Costa, M. Souza, L. Reis","doi":"10.1590/s0100-83582020380100046","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100046","url":null,"abstract":"ABSTRACT: Weeds and microorganisms interacting with their rhizosphere may influence nutrient absorption, which is an important factor for plant competition. The purpose of this study was to evaluate the microbiological activity, inorganic phosphorus solubilization (Pi) and acid phosphatase in the cultivated soil, in a combination of soybean (Glycine max) plants and weeds. Soybeans were cultivated in monoculture and in competition with Bidens pilosa, Brachiaria decumbens (Syn. Urochloa decumbens) and Eleusine indica, under two conditions: a) plants competing without contact between the roots b) plants competing with contact between the roots. A nylon screen with a 50 µm mesh was added to prevent contact between the roots of the species in competition so that the substratum could be separated in the vase. The experiment was conducted in randomized blocks, with four replications. The soybeans in competition with weeds led to lower oxidation of organic matter per unit of microbial biomass, resulting in a lower metabolic quotient, compared with the soybean monoculture. The contact between soybean roots and B. pilosa, B. decumbens and E. indica maintained a strong influence, raising the solubilization of Pi, respectively valued at 51, 39 and 31% in relation to the cultivation of each species with a nylon screen. Microbiological activity, inorganic phosphorus solubilization and acid phosphatase were altered by plant species, combinations of weeds and soybean plants in competition; by root contact in some cases. Thus, the microbiological activity of the soil can influence competition strategies and plant development.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Comparing Fitness Cost Associated with Haloxyfop-R Methyl Ester Resistance in Winter Wild Oat Biotypes 冬季野生燕麦生物型对Haloxyfop-R甲酯抗性的适应度成本比较

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100042

S. Hassanpour-bourkheili, J. Gherekhloo, B. Kamkar, S. Ramezanpour

{"title":"Comparing Fitness Cost Associated with Haloxyfop-R Methyl Ester Resistance in Winter Wild Oat Biotypes","authors":"S. Hassanpour-bourkheili, J. Gherekhloo, B. Kamkar, S. Ramezanpour","doi":"10.1590/s0100-83582020380100042","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100042","url":null,"abstract":"ABSTRACT: Consecutive application of herbicides has led to the evolution of herbicide-resistant weeds. This resistance is often associated with a fitness cost. Hence, a completely randomized design experiment with three replications was conducted to evaluate the fitness cost of haloxyfop-R methyl ester resistant winter wild oat biotypes (Avena ludoviciana Durieu) possessing Ile-2041-Asn mutation compared to susceptible ones. The pre-germinated F2 generation winter wild oat biotypes were sown in 0.2 m2 pots containing 50 cm of silty-loam soil outdoors and their growth parameters including tiller number, plant height, leaves per plant, leaf area per plant, chlorophyll content index, leaf dry weight, and plant dry weight were measured 30, 70, 100, 115 and 130 days after planting. Leaf area index, leaf area ratio, specific leaf area, relative growth rate, net assimilation rate, and crop growth rate were also calculated. Seed production, 1000 kernel weight, and flag leaf area were measured at the end of the growth period. According to the results, no fitness cost was observed between susceptible and resistant biotypes, indicating that susceptible biotypes may not overcome resistant ones in the field. Although imposing a new selective pressure via application of an herbicide possessing a different mode of action may control both susceptible and resistant biotypes, herbicide rotation must be adapted to impede the evolution of further resistance. Also, the same non-chemical weed management methods such as careful selection of sowing date can be implemented to ameliorate adverse effects of this weed on crop production.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Timing of weed management and yield penalty due to delayed weed management in soybean 大豆杂草管理的时机与延迟杂草管理造成的产量损失

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100072

Olumide S. Daramola

{"title":"Timing of weed management and yield penalty due to delayed weed management in soybean","authors":"Olumide S. Daramola","doi":"10.1590/s0100-83582020380100072","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100072","url":null,"abstract":"Background: Weed interference is a major limiting factor for economically viable soybean production. Appropriate timing of weed management would enable farmers to make more efficient use of resources for weed management. Objective: The objective of this study was to determine the critical period for weed competition and appropriate timing of weed management for optimum yield of soybean. Methods: The treatments consisted of periods of weed infestation and weed removal for the first 14, 28, 42 and 56 days after sowing (DAS), and till harvest in a randomized complete block design with three replications in 2016 and 2017. Results: Soybean yields in both years ranged from 914-945 kg ha-1 with no weed control to 1,984-2,127 kg ha-1 in the weed-free plots; a yield loss of 53-56%. Weed infestation for the first 14 DAS had no detrimental effect on growth and yield of soybean provided the weeds were subsequently removed. Increasing period of weed interference from 14 to 42 DAS resulted in a steady decline in growth and yield of soybean. Yield losses equivalent of 32-37 kg ha-1 resulted for each day that weed control was delayed between 14 and 42 DAS. Subsequent weed control after 42 DAS did not improve growth and yield significantly, nor obviate yield depression of the crop compared to crop weed-infested till harvest. Conclusions: Results indicated that the critical period of weed competition in soybean was between 14 and 42 DAS. Hence soybean should be maintained weed-free during this period to avoid high yield loss.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Sourgrass phenological stage and efficacy of ACCase-inhibiting herbicides 酸草物候期及抗accase除草剂的药效

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100089

Jéssica C. Presoto, Jeisiane F. Andrade, Laura A. Souza, Laura S. Teixeira, Saul J.P. Carvalho

{"title":"Sourgrass phenological stage and efficacy of ACCase-inhibiting herbicides","authors":"Jéssica C. Presoto, Jeisiane F. Andrade, Laura A. Souza, Laura S. Teixeira, Saul J.P. Carvalho","doi":"10.1590/s0100-83582020380100089","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100089","url":null,"abstract":"Background: Sourgrass (Digitaria insularis) is a highly disseminated weed in Brazil. It is a perennial grass weed that has high infesting capacity in agricultural areas and presents glyphosate-resistant biotypes. An effective post-emergence control of sourgrass plants depends on their phenological stage at the time of herbicide application. Objective: This work was developed with the objective of evaluating the effect of the sourgrass phenological stage at the time of herbicide application on the efficacy of ACCase-inhibiting herbicides. Methods: Two independent experiments were conducted under greenhouse conditions to evaluate two ACCase-inhibiting herbicides: clethodim, and haloxyfop. The treatments were applied using a completely randomized block design, with an 8×4 factorial arrangement consisted of 8 herbicide rates (4, 2, 1, 1/2, 1/4, 1/8, and 1/16 times the recommended rate, and a control plot without herbicide application) and four phenological stages of sourgrass. Results: The development of sourgrass plants after tillering decreased the efficacy of the herbicide molecules; however, clethodim and haloxyfop were efficient to control sourgrass at earlier developmental stages. Morphological, anatomical, and physiological changes in older plants may explain the lower susceptibility to herbicides. Conclusions: Other control techniques should be considered for sourgrass plants at later developmental stages, such as sequential application or herbicide mixtures, to increase the efficacy of ACCase herbicides.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Residual herbicides increase the period prior to interference in soybean cultivars 残留除草剂延长了大豆品种的干扰期

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Planta Daninha Pub Date : 2020-01-01 DOI: 10.1590/s0100-83582020380100091

M. A. Rizzardi, A. P. Rockenbach, T. Schneider

{"title":"Residual herbicides increase the period prior to interference in soybean cultivars","authors":"M. A. Rizzardi, A. P. Rockenbach, T. Schneider","doi":"10.1590/s0100-83582020380100091","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100091","url":null,"abstract":"Background: The pre-emergence herbicides diclosulam and flumioxazin are used to weed control in soybean. We hypothesized management of the new emergence of weeds in the early development stages of the soybean could alter the periods of interference. Thus, the period prior to interference allows and increases the canopy closure spaces before the critical period and disfavors the development of weeds inside the vegetative canopy. Objective: This study aimed to evaluate whether the period prior to interference of soybean cultivars was altered due to the application of residual pre-emergence herbicides. Methods: Two experiments were conducted with the soybean cultivars ‘NA 5909 RG’ and ‘P95R51’. One day before sowing in the main plots, the herbicide treatments paraquat (control without residual herbicide), paraquat+diclosulam, and paraquat+flumioxazin were applied. In the sub-plots, the increasing periods of coexistence of soybean with weeds of 0, 7, 14, 21, 28, 35, 42, and 49 days after the emergence of soybean were allocated. Results: The control without residual herbicide had the lowest period prior to interference and the most considerable reductions in grain yield when compared with residual herbicides in both experiments. The presence of residual herbicide increased the period prior to interference because they controlled the initial emergence of the major weeds in the experimental area. Conclusions: The use of the herbicides with residual activity diclosulam and flumioxazin increased the period prior to interference of ‘NA 5909 RG’ and ‘P95R51’ in areas infested mainly with horseweed and radish.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6