Selectivity and efficiency of herbicides in cassava on the floodplain of the Solimões river

Cassava is grown on the floodplains of the Solimões river and guarantees food security and income for farmers. However, negative interference of weeds can result in a significant yield loss in the crop. Therefore, the aim of this study was to evaluate the selectivity of herbicides and efficiency of chemical weed control in the cassava ‘Aipim-manteiga’ cultivar, in the floodplain of the Solimões river, in Iranduba, Amazonas. The experimental design was in randomized blocks with four replications. The herbicides evaluated were clomazone (1080 g ha-1), diuron (1750 and 2500 g ha-1) and oxadiazon (400 and 800 g ha-1), applied alone or with hoeing 90 days after planting (DAP). Two control treatments were included: weeding (hoeing) at 30, 60, 90 and 120 DAP and with no weed control. Clomazone caused mild toxicity in the plants, while with diuron and oxadiazon toxicity was moderate; all three were considered safe for the crop. The plant population of the crop was not affected by the herbicides. Clomazone afforded effective weed control up to 45 DAP only, and weeding was necessary at 90 DAP to eliminate negative interference by the weeds on crop yield. Diuron and oxadiazon were effective in controlling weeds throughout the crop cycle of the cassava. Weed interference during the crop life cicle reduced yield by 83.8%.

Download Full-text

Herbicide selectivity and weed control in cowpea

Revista Agro mbiente On-line ◽

10.18227/1982-8470ragro.v13i0.5414 ◽

2019 ◽

Vol 13 ◽

pp. 101

Author(s):

José Roberto Antoniol Fontes ◽

Inocencio Junior Oliveira ◽

Ronaldo Ribeiro Morais

Keyword(s):

Weed Control ◽

Yield Loss ◽

The Other ◽

Field Conditions ◽

Effectiveness Evaluation ◽

Control Effectiveness ◽

Weed Interference ◽

Crop Cycle ◽

Delayed Development

Weeds negatively affect cowpea plants, causing reduced growth, delayed development and yield loss. The aim of this study was to assay selectivity and effectiveness of weed control herbicides in cowpea cropping field conditions. For selectivity evaluation, the herbicide S-metolachlor, was used pre-emergence (PRE), and carfentrazone-ethyl, clethodim, fenoxaprop-p-ethyl, fluazifop-p-butyl and quizalofop-p-ethyl post-emergence (POST). In effectiveness evaluation, S-metolachlor (PRE), and carfentrazone-ethyl (POST), S-metolachlor in PRE and fluazifop-p-butyl (POST), clethodim, carfentrazone-ethyl and clethodim, fenoxapropp- ethyl, carfentrazone-ethyl and fenoxaprop-p-ethyl, fluazifop-p-butyl, carfentrazone-ethyl and fluazifop-pbutyl, quizalofop-p-ethyl and carfentrazone-ethyl and quizalofop-p-ethyl (POST). Two controls were included, one with weeding at 15 and 35 days after sowing (DAS) and the other without weed control. Carfentrazone-ethyl caused mild phytotoxicity in plants seven days after application, but did not reduce yield (2337 kg ha-1). The levels of weed control and productivity obtained with S-metolachlor alone or in association with carfentrazoneethyl or fluazifop-p-butyl, associated or not with carfentrazone-ethyl, were similar to those obtained with weeds. Spraying with carfentrazone-ethyl alone resulted in low control effectiveness and reduced yield (1511 kg ha-1). Weed interference during the crop cycle reduced yield by 77% (531 kg ha-1). The selectivity and effectiveness obtained with the herbicides should be considered as an agronomic and economically-viable.

Download Full-text

The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha43210031 ◽

2015 ◽

Vol 43 (2) ◽

pp. 355-360 ◽

Cited By ~ 1

Author(s):

Dogan ISIK ◽

Adem AKCA ◽

Emine KAYA ALTOP ◽

Nihat TURSUN ◽

Husrev MENNAN

Keyword(s):

Weed Control ◽

Weed Management ◽

Critical Period ◽

Field Experiments ◽

Yield Loss ◽

Cropping Systems ◽

Control Period ◽

Relative Yield ◽

Yield Data ◽

Weed Interference

Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days) which corresponded to 8 to 66 days after crop emergence (DAE) and between 135-958 GDD (10 to 63 DAE) in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

Download Full-text

Potential yield loss in grain sorghum (Sorghum bicolor) with weed interference in the United States

Weed Technology ◽

10.1017/wet.2020.12 ◽

2020 ◽

Vol 34 (4) ◽

pp. 624-629 ◽

Cited By ~ 1

Author(s):

J. Anita Dille ◽

Phillip W. Stahlman ◽

Curtis R. Thompson ◽

Brent W. Bean ◽

Nader Soltani ◽

...

Keyword(s):

United States ◽

Weed Control ◽

Weed Management ◽

Yield Loss ◽

Science Research ◽

The United States ◽

Grain Sorghum ◽

Control Cost ◽

Potential Yield ◽

Weed Interference

AbstractPotential yield losses in grain sorghum due to weed interference based on quantitative data from the major grain sorghum-growing areas of the United States are reported by the WSSA Weed Loss Committee. Weed scientists and extension specialists who researched weed control in grain sorghum provided data on grain sorghum yield loss due to weed interference in their region. Data were requested from up to 10 individual experiments per calendar year over 10 yr between 2007 and 2016. Based on the summarized information, farmers in Arkansas, Kansas, Missouri, Nebraska, South Dakota, and Texas would potentially lose an average of 37%, 38%, 30%, 56%, 61%, and 60% of their grain sorghum yield with no weed control, and have a corresponding annual monetary loss of US $19 million, 302 million, 7 million, 32 million, 25 million, and 314 million, respectively. The overall average yield loss due to weed interference was estimated to be 47% for this grain sorghum-growing region. Thus, US farmers would lose approximately 5,700 million kg of grain sorghum valued at approximately US $953 million annually if weeds are not controlled. With each dollar invested in weed management (based on estimated weed control cost of US $100 ha−1), there would be a return of US $3.80, highlighting the return on investment in weed management and the importance of continued weed science research for sustaining high grain sorghum yield and profitability in the United States.

Download Full-text

Fluridone and acetochlor cause unacceptable injury to pumpkin

Weed Technology ◽

10.1017/wet.2019.42 ◽

2019 ◽

Vol 33 (5) ◽

pp. 748-756 ◽

Cited By ~ 1

Author(s):

J. Harrison Ferebee ◽

Charles W. Cahoon ◽

Thierry E. Besançon ◽

Michael L. Flessner ◽

David B. Langston ◽

...

Keyword(s):

New Jersey ◽

Weed Control ◽

Broad Spectrum ◽

Yield Loss ◽

Field Research ◽

Separate Study ◽

Control Field ◽

Common Ragweed ◽

Emulsifiable Concentrate ◽

Significant Yield

AbstractResidual herbicides are routinely applied to control troublesome weeds in pumpkin production. Fluridone and acetochlor, Groups 12 and 15 herbicides, respectively, provide broad-spectrum PRE weed control. Field research was conducted in Virginia and New Jersey to evaluate pumpkin tolerance and weed control to PRE herbicides. Treatments consisted of fomesafen at two rates, ethalfluralin, clomazone, halosulfuron, fluridone, S-metolachlor, acetochlor emulsifiable concentrate (EC), acetochlor microencapsulated (ME), and no herbicide. At one site, fluridone, acetochlor EC, acetochlor ME, and halosulfuron injured pumpkin 81%, 39%, 34%, and 35%, respectively, at 14 d after planting (DAP); crop injury at the second site was 40%, 8%, 19%, and 33%, respectively. Differences in injury between the two sites may have been due to the amount and timing of rainfall after herbicides were applied. Fluridone provided 91% control of ivyleaf morningglory and 100% control of common ragweed at 28 DAP. Acetochlor EC controlled redroot pigweed 100%. Pumpkin treated with S-metolachlor produced the most yield (10,764 fruits ha–1) despite broadcasting over the planted row; labeling requires a directed application to row-middles. A separate study specifically evaluated fluridone applied PRE at 42, 84, 126, 168, 252, 336, and 672 g ai ha–1. Fluridone resulted in pumpkin injury ≥95% when applied at rates of ≥168 g ai ha–1; significant yield loss was noted when the herbicide was applied at rates >42 g ai ha–1. We concluded that fluridone and acetochlor formulations are unacceptable candidates for pumpkin production.

Download Full-text

The Critical Period of Weed Control for Lentil in Western Canada

Weed Science ◽

10.1614/ws-d-11-00051.1 ◽

2011 ◽

Vol 59 (4) ◽

pp. 517-526 ◽

Cited By ~ 11

Author(s):

L. K. Fedoruk ◽

E. N. Johnson ◽

S. J. Shirtliffe

Keyword(s):

Weed Control ◽

Critical Period ◽

Inverse Relationship ◽

Yield Loss ◽

Western Canada ◽

Crop Canopy ◽

Herbicide Application ◽

Weed Biomass ◽

Weed Interference ◽

Residual Herbicide

Weed control in lentil is difficult because lentil is a poor competitor with weeds and few POST broadleaf herbicides are available. Imadazolinone-tolerant lentils have more herbicide options, but the optimum timing for herbicide application is not known. The critical period of weed control (CPWC) is the period in a crop's life cycle when weeds must be controlled in order to prevent yield loss. The objective of this research was to determine the CPWC for lentil. We made lentil remain weedy or weed-free from 0 to 11 aboveground nodes to investigate the durations of weed interference and weed-free period, respectively. It was found that lentil has a CPWC beginning at the five-node stage and continuing to the 10-node stage. There was an inverse relationship between weed biomass and lentil yield; that is, lentil yield was highest when weed biomass is minimal. We propose that the CPWC begins when weeds start to accumulate significant biomass and ends with crop canopy closure. Therefore, to maximize lentil yields, growers should consider using a POST residual herbicide that can control weeds during the CPWC.

Download Full-text

Perspectives on Potential Soybean Yield Losses from Weeds in North America

Weed Technology ◽

10.1017/wet.2016.2 ◽

2017 ◽

Vol 31 (1) ◽

pp. 148-154 ◽

Cited By ~ 26

Author(s):

Nader Soltani ◽

J. Anita Dille ◽

Ian C. Burke ◽

Wesley J. Everman ◽

Mark J. VanGessel ◽

...

Keyword(s):

North America ◽

Weed Control ◽

Crop Yield ◽

Yield Loss ◽

Census Data ◽

Commodity Prices ◽

Yield Losses ◽

Soybean Yield ◽

Weed Interference ◽

The Us

Weeds are one of the most significant, and controllable, threats to crop production in North America. Monetary losses because of reduced soybean yield and decreased quality because of weed interference, as well as costs of controlling weeds, have a significant economic impact on net returns to producers. Previous Weed Science Society of America (WSSA) Weed Loss Committee reports, as chaired by Chandler (1984) and Bridges (1992), provided snapshots of the comparative crop yield losses because of weeds across geographic regions and crops within these regions after the implementation of weed control tactics. This manuscript is a second report from the current WSSA Weed Loss Committee on crop yield losses because of weeds, specifically in soybean. Yield loss estimates were determined from comparative observations of soybean yields between the weedy control and plots with greater than 95% weed control in studies conducted from 2007 to 2013. Researchers from each US state and Canadian province provided at least three and up to ten individual comparisons for each year, which were then averaged within a year, and then averaged over the seven years. These percent yield loss values were used to determine total soybean yield loss in t ha−1and bu acre−1based on average soybean yields for each state or province as well as current commodity prices for a given year as summarized by USDA-NASS (2014) and Statistics Canada (2015). Averaged across 2007 to 2013, weed interference in soybean caused a 52.1% yield loss. Based on 2012 census data in the US and Canada soybean was grown on 30,798,512 and 1,679,203 hectares with production of 80 million and 5 million tonnes, respectively. Using an average soybean price across 2007 to 2013 of US $389.81 t−1($10.61 bu−1), farm gate value would be reduced by US $16.2 billion in the US and $1.0 billion in Canada annually if no weed management tactics were employed.

Download Full-text

Critical Period of Weed Control in Snap Bean on Organic Soils in South Florida

HortScience ◽

10.21273/hortsci12536-17 ◽

2018 ◽

Vol 53 (8) ◽

pp. 1129-1132

Author(s):

Dennis C. Odero ◽

Alan L. Wright

Keyword(s):

Weed Control ◽

Critical Period ◽

Yield Loss ◽

South Florida ◽

Maximum Length ◽

Organic Soils ◽

Open Flower ◽

Trifoliate Leaf ◽

Snap Bean ◽

Weed Interference

Field studies were conducted in 2011 and 2012 in Belle Glade, FL, to evaluate the critical period of weed control (CPWC) in snap bean grown on organic soils in the Everglades Agricultural Area (EAA) of South Florida. Treatments consisting of increasing duration of weed interference and weed-free period were imposed at weekly intervals from 0 to 7 weeks after emergence (WAE) of snap bean. The beginning and end of the CPWC based on 2.5%, 5%, and 10% snap bean acceptable yield loss (AYL) levels were determined by fitting log-logistic and Gompertz models to represent increasing duration of weed interference and weed-free period, respectively. Based on 2.5% yield loss, the CPWC was 7.2 weeks long, beginning 1.2 (cotyledon and unifoliate leaf) and ending 8.4 WAE (mid-pod set, 50% of pods reached maximum length). At 5% yield loss, the CPWC was 5.0 weeks, beginning 1.7 (first to second trifoliate leaf) and ending 6.7 WAE (mid-flower to early pod set, 50% of flowers open and one pod reached maximum length). At 10% yield loss, the CPWC was 3.0 weeks, beginning 2.2 (second trifoliate leaf) and ending 5.2 WAE (early flowering, one open flower). Based on these results, the beginning of CPWC was hastened, whereas the end was delayed at different yield loss levels showing that acceptable weed control in snap bean on organic soils in the EAA is required throughout much of the growing season to minimize yield loss.

Download Full-text

The Critical Period for Weed Control in Corn in Turkey

Weed Technology ◽

10.1614/wt-05-102.1 ◽

2006 ◽

Vol 20 (4) ◽

pp. 867-872 ◽

Cited By ~ 11

Author(s):

Dogan Isik ◽

Husrev Mennan ◽

Bekir Bukun ◽

Ahmet Oz ◽

Mathieu Ngouajio

Keyword(s):

Weed Control ◽

Critical Period ◽

Yield Loss ◽

Relative Yield ◽

Field Studies ◽

The Black Sea ◽

Yield Data ◽

Black Sea Region ◽

Weed Interference ◽

Loss Level

Field studies were conducted in 2001 and 2002 in the Black Sea Region of northern Turkey to determine the critical period for weed control (CPWC) in corn and the effects of weed interference on corn height. Treatments of increasing duration of weed interference and weed-free period were imposed at weekly intervals from 0 to 12 wk after crop emergence (WAE). The CPWC was determined with the use of 2.5, 5, and 10% acceptable yield loss levels by fitting logistic and Gompertz equations to relative yield data. With 5% yield loss level, the CPWC was 5 wk, starting at 0.2 WAE and ending at 5.2 WAE, which corresponded to the one- to five-leaf stage of corn. The CPWC increased to 8.9 wk, starting at 0 WAE and ending at 8.9 WAE, at the 2.5% yield loss level. At 10% yield loss level, the CPWC decreased to 1.7 wk, starting at 2.1 WAE and ending at 3.8 WAE.

Download Full-text

COMPETITIVE ABILITY OF BEAN CULTIVARS WITH HAIRY BEGGARTICKS

Revista Caatinga ◽

10.1590/1983-21252017v30n405rc ◽

2017 ◽

Vol 30 (4) ◽

pp. 855-865 ◽

Cited By ~ 1

Author(s):

LEANDRO GALON ◽

RICARDO TREVISOL ◽

CESAR TIAGO FORTE ◽

SIUMAR PEDRO TIRONI ◽

FRANCISCO WILSON REICHERT JÚNIOR ◽

...

Keyword(s):

Experimental Design ◽

Competitive Analysis ◽

Competitive Ability ◽

Dry Mass ◽

Environmental Resources ◽

Replacement Series ◽

Negative Interference ◽

Black Bean ◽

Weed Interference ◽

Morphological Variables

ABSTRACT Weed interference is a factor that limits the productivity of beans and, among these, hairy beggarticks is one of the main species competing with the crop for environmental resources. Thus, the aim of this study is to evaluate the competitive ability of black bean cultivars (BRS Campeiro, IPR Uirapuru, SCS204 Predileto and BRS Supremo) in the presence of a biotype of hairy beggarticks. The experimental design is a completely randomized block with four replications. Treatments were arranged in a replacement series, consisting of a proportion of the crop and the hairy beggarticks: 100:0; 75:25; 50:50: 24:75, and 0:100, which corresponds to 40:0, 30:10, 20:20, 10:30, and 0:40 plant pots1. We accomplished competitive analysis through diagrams applied to the replacement series, as well as using relative competitive indices. The leaf area and shoot dry mass were evaluated at 40 days after emergence of the species. There was competition between bean cultivars and hairy beggarticks for the same environmental resources, causing negative interference in the growth of the species, independent of the proportion of plants. Bean cultivars had a lower relative loss by reducing the morphological variables of the hairy beggarticks, thereby demonstrating superiority in its competitive ability in relation to the weed. Interspecific competition is less damaging than intraspecific competition for both species.

Download Full-text

Weed Interference on ‘Prata-Anã’ Banana Production

Planta Daninha ◽

10.1590/s0100-83582019370100150 ◽

2019 ◽

Vol 37 ◽

Author(s):

G.C. SANTOS ◽

V.M. MAIA ◽

I. ASPIAZÚ ◽

M.C.T. PEREIRA ◽

S.L.R. DONATO ◽

...

Keyword(s):

Experimental Design ◽

Weed Control ◽

Fruit Quality ◽

Experimental Period ◽

Northern Region ◽

Production Cycle ◽

Banana Production ◽

Weed Interference ◽

Reproductive Cycles ◽

Satisfactory Quality

ABSTRACT: In the state of Minas Gerais, the northern region is one of the main banana production cores. Weed interference can reduce crop growth and, consequently, lead to reduced yield and fruit quality. Therefore, the objective of this study was to evaluate the interference of weeds in the production of the first and second cycles of ‘Prata-Anã’ bananas. The experimental design was randomized blocks, with ten treatments and three replicates, evaluated in two crop cycles. The treatments were ten periods of weed control, from planting: without control; control throughout the whole experimental period; control only in the first month after planting; control until the second; third; fourth; fifth; sixth; eighth and tenth months after planting. The agronomic and productive characteristics of the ‘Prata-Anã’ bananas were evaluated aton harvest. The maintenance of ‘Prata-Anã’ bananas without weed coexistence for up to 30 days after planting was enough to obtain fruits with satisfactory quality and productivity, both in the first and in the second production cycle, without altering the vegetative and reproductive cycles.

Download Full-text