scholarly journals WEED CONTROL IN “LL” MAIZE TOLERANT TO GLUFOSINATE-AMMONIUM

2020 ◽  
Vol 19 ◽  
pp. 17
Author(s):  
LEANDRO GALON ◽  
MAICON RODRIGUES DA SILVA ◽  
ALEXANDRE FERREIRA DA SILVA ◽  
ANDRÉ DALPONTE MENEGAT ◽  
RENAN PAWELKIEWICZ ◽  
...  
Keyword(s):  
Weed Control ◽  
Yield Loss ◽  
Maize Yield ◽  
Grain Weight ◽  
The Other ◽  
Thousand Grain Weight ◽  
Glufosinate Ammonium ◽  
Subsequent Application ◽  
Control Spectrum ◽  
Ear Number

The glufosinate-ammonium is an herbicide with contact action and, whenused in tolerant LL maize, requires associations with other products to improve the weed control spectrum and increase the residual period in the area. The aim of this work was to evaluate the efficacy and selectivity of glufosinate-ammonium, applied alone and in combination with other herbicides, for weed control in maize crops. The treatments consisted of two strategies. In the first one, the following herbicides were applied in pre-emergence conditions: atrazine, [atrazine + simazine], [atrazine + oil], [atrazine + S-metolachlor], and S-metolachlor; with the subsequent application of glufosinate-ammonium in post-emergence condition of maize. The second application method corresponded to the use of glufosinate-ammonium, alone and combined with nicosulfuron + mesotrione and the other products used in the first strategy, in addition to two control areas, being one weed-infested and the other weed-free. Phytotoxicity on maize and weed control were assessed. Ear insertion height, number of rows per ear, number of grains per row, thousand grain weight and maize yield were determined upon harvesting. The herbicides were effective and did not cause yield loss to the crop. The herbicides applied in combination with glufosinate-ammonium were efficient in regard to weed control and selective to maize.

Texasweed (Caperonia palustris) Interference in Drill-Seeded Rice

2012 ◽  
Vol 26 (2) ◽  
pp. 356-363 ◽  
Author(s):  
Rakesh K. Godara ◽  
Billy J. Williams ◽  
Eric P. Webster ◽  
James L. Griffin ◽  
James P. Geaghan
Keyword(s):  
Path Analysis ◽  
Critical Period ◽  
Detrimental Effect ◽  
Yield Loss ◽  
Rice Yield ◽  
Field Research ◽  
Yield Component ◽  
Grain Weight ◽  
Thousand Grain Weight ◽  
Rice Season

Field research was conducted near Saint Joseph, LA, in 2008 and 2009 to evaluate Texasweed interference in drill-seeded rice. Season-long Texasweed interference at 1 plant m−2was estimated to cause 5% yield loss. Yield loss from 10 and 50 plants m−2was 31 and 61%, respectively. Yield loss was primarily due to a reduction in effective tillers per square meter. Thousand-grain weight of rice was not affected by season-long Texasweed interference. Path analysis indicated yield component compensation, i.e., a reduction in effective tillers per square meter probably caused an increase in grains per panicle. However, that effect was not strong enough to reverse the detrimental effect of reduced effective tillers per square meter on rice yield. The critical period of Texasweed interference to cause more than 5% yield loss was estimated to be between 0 and 6 wk after rice emergence.

scholarly journals Evaluation of Runner-Type Peanut Cultivar Tolerance to Paraquat Tank Mixes

2020 ◽  
Vol 47 (2) ◽  
pp. 103-110
Author(s):  
Katilyn Price ◽  
Xiao Li ◽  
Andrew Price ◽  
Charles Chen ◽  
Timothy Grey
Keyword(s):  
Weed Control ◽  
Yield Loss ◽  
Growth Parameters ◽  
Field Trials ◽  
Growth And Yield ◽  
Henry County ◽  
Peanut Cultivars ◽  
Herbicide Programs ◽  
Control Spectrum

ABSTRACT Herbicide tank mixes are often used to reduce peanut injury caused by paraquat and broaden the weed control spectrum. New peanut cultivars are continuously being introduced therefore determining tolerance to paraquat based herbicide programs is essential to provide growers with appropriate recommendations. The objective of this trial was to evaluate effect of paraquat based herbicide programs on newer peanut cultivars growth and yield. Field trials were conducted in Macon, Henry and Baldwin counties in Alabama in 2016 and 2017 and the peanut cultivars ‘Georgia 06G', ‘Georgia 12Y', ‘Georgia 14N', and ‘TufRunner 511’ were evaluated. Paraquat was applied alone (210, 280, 420 g ai/ha), in tank mixes with either bentazon plus acifluorfen or 2,4-DB and one of the following, S-metolachlor, pyroxasulfone, acetochlor, or pyroxasulfone plus carfentrazone at the highest labeled rates 3 to 4 wk after peanut planting. No cultivar by treatment interactions were observed for any growth parameters evaluated for any location. In 2017, paraquat either applied at 280 g ai/ha alone, tank mixed with S-metolachlor plus 2,4-DB, or with S-metolachlor plus bentazon plus acifluorfen significantly reduced canopy widths of 22 to 30%, 12 to 22%, and 20 to 37% respectively at 45 to 48 DAP when compared to the non-treated check (NTC). Yield reductions compared to the NTC were rare, paraquat plus bentazon plus acifluorfen plus pyroxasulfone plus carfentrazone had a 13% yield loss in Henry County and a 7% yield loss with paraquat 280 g ai/ha at Baldwin County in 2016 only. Data indicates peanut stunting may be observed following applications of paraquat tank mixes evaluated in this study, but it is unlikely these effects result in yield loss.

scholarly journals Relationship Between Eyespot Severity and Productivity of Winter Wheat in Lithuania

2014 ◽  
Vol 32 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Jūratė Ramanauskienė ◽  
Irena Gaurilčikienė ◽  
Rūta Česnulevičienė
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Grain Weight ◽  
Thousand Grain Weight ◽  
Grain Number ◽  
Wheat Varieties ◽  
Cropping Season ◽  
Winter Wheat Cultivars ◽  
Severity Of The Disease ◽  
The Relationship

Abstract Cereal yield loss from eyespot directly depends on the severity of the disease. The aim of this study was to establish the relationship between eyespot damage in winter wheat and components of yield of winter wheat cultivars Ada, Mulan and Tukan in Lithuania in the 2011/2012 cropping season. Several eyespot did not decrease the grain number per ear cv. of Tukan while for cvs. Ada and Mulan the decrease was 14 and 15%, respectively; however, the grain number per ear of moderately eyespot-affected stems of cv. Ada did not differ from that of visually healthy stems. For cv. Ada, the grain weight per ear of moderately affected stems was 5.8% less and that of severely affected stems was 12.8% less than that of healthy stems, while for cv. Mulan the decrease in grain weight per ear was 40.3 and 35.5%, respectively and for cv. Tukan it was 59.0 and 63.2%, respectively for moderately and severely affected stems. The decrease in thousand grain weight of moderately eyespot-affected stems of cv. Ada was less (6.5%) compared with that of cv. Mulan (31.3%) and cv. Tukan (55.8%). Thousand grain weight of severely eyespot-affected stems of cvs. Ada, Mulan and Tukan was 22.2, 26.0, and 65.0%, respectively, less than that of healthy stems. Screening of healthy, moderately and severely affected plants of the winter wheat varieties Ada, Mulan and Tukan for grain number per ear, grain weight per ear and TGW revealed that these varieties differed in tolerance to eyespot

Penentuan Tempoh Kritikal Untuk Mengawal Rumpai dalam Kawasan Penanaman Padi Wangi MRQ 76, Q 88 dan Q 89

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Chong Tet Vun ◽  
Azimah Abd Kadir ◽  
Azmi Man ◽  
Chew See Eng ◽  
Baharudin Abas ◽  
...  
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Slow Growth ◽  
The Other ◽  
Fragrant Rice ◽  
Other Hand ◽  
Hot Climate ◽  
Competition Ability ◽  
Loss Level

A study on critical period (CP) for weed control in fragrant rice MRQ 76, Q 88 and Q 89 was conducted in main season 2012/2013 and off season 2013 at MARDI Seberang Perai. The results showed that the CPs (based on 5% acceptable yield loss level (AYL)) for weed control of MRQ 76, Q 88 and Q 89 planted in main season were from 5 to 64, 13 to 68 and 8 to 66 DAS (Days after sowing), respectively. On the other hand, CPs of MRQ 76, Q 88 and Q 89 planted in off season were from 6 to 73, 9 to 81 and 3 to 83 DAS, respectively. If based on 10% AYL, CPs of MRQ76, Q 88 and Q 89 planted in main season were from 19 to 38, 28 to 41 and 14 to 53 DAS, respectively. CPs (based on 10% AYL) of MRQ76, Q 88 and Q 89 planted in off season were from 15 to 55, 19 to 68 and 10 to 66 DAS, respectively. The study clearly demonstrated that CPs of off season were longer than CPs of main season. The dry and hot climate in off season probably caused the slow growth of fragrant rice and eventually affected the competition ability of rice against the weeds. 

Population studies with wheat: I. Sampling

1939 ◽  
Vol 29 (1) ◽  
pp. 76-110 ◽  
Author(s):  
H. G. Hudson
Keyword(s):  
Large Scale ◽  
Population Studies ◽  
Sampling Error ◽  
Grain Weight ◽  
The Other ◽  
Sampling Unit ◽  
Stem Number ◽  
Optimum Sampling ◽  
The Mean ◽  
Ear Number

The design and field technique of two large scale experiments, laid down to investigate the problems of sampling and “propinquity”, are described in detail. These experiments were designed so that the plant number, stem number, ear number, straw weight and grain weight for 7200 lengths of 6 in. of drill row, together with the position of each observation, might be obtained.The lowest sampling error, expressed as a percentage of the mean, is obtained by using the smallest sampling unit, but the large number of sampling units of this size that would have to be taken make it impracticable. The optimum sampling unit consists of 6 ft. of drill row, taken as 3 ft. of two adjacent rows. The size of the sampling unit is of greater importance than the shape in determining its accuracy, and little s lost by using sampling units of 18 in. of five adjacent rows.The nature of the observation affects the degree of sampling. In the experiments examined the plant number, stem number and ear number require very similar sampling, but grain weight requires a sample which is about twice as large as that required by the other observations.The percentage of the plot that must be taken as a sample (the sampling percentage) to obtain any given accuracy is related to the size of plot: the larger the plot, the lower the sampling percentage necessary. To obtain an error of 5% of the mean the sampling percentage for grain weight is approximately 5% in 1/20 acre plots, 15% in 1/100 acre plots and 43% in 1/600 acre plots if the plots are not subdivided. These percentages are similar to those calculated from various randomized block experiments in Cambridge.

Assessment of yield loss caused by common root rot in wheat cultivars in Queensland

1992 ◽  
Vol 43 (1) ◽  
pp. 43 ◽  
Author(s):  
GB Wildermuth ◽  
RD Tinline ◽  
RB McNamara
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Root Rot ◽  
Yield Loss ◽  
Grain Weight ◽  
The Other ◽  
Regression Equations ◽  
Yield Losses ◽  
Common Root ◽  
Common Root Rot

The effects of common root rot (CRR) caused by Bipolaris sorokiniana on grain yield, number of tillers, number of grains and grain weight of wheat plants were determined in four field experiments. Sites with different soil populations of B. sorokiniana were selected and inoculum of the fungus added to some plots. Disease and yield measurements were made on eight cultivars and lines differing in susceptibility to CRR. Timgalen, Songlen and Hartog were susceptible whereas Kite, 1008 C16, 141-4 and ISWYN 32 were partially resistant to CRR. Grain yield, tiller and grain number, but not grain weight decreased as disease severity increased. Diseased plants had lower tiller numbers than healthy ones and as a consequence a reduced number of grains and grain yield per plant. Five methods were compared for estimating yield loss caused by the disease. Polynomial regression equations for each cultivar between yield and disease rating of sub-crown internodes or multiple regression equations between yield and disease parameters of sub-crown internodes or tiller bases were established. A third method involved the projection of yield losses from one cultivar to other cultivars and in a fourth method yield losses were estimated from actual yields. In addition, an equation Yield loss (%) = 3 46 + 0.23 disease severity) (%) was established in one experiment and used as a fifth method in the other experiments. Yield losses estimated by methods 1 and 2 were similar and higher than those from the other methods. In areas where disease severity is high, methods 1 and 5 appear to be the most suitable for determining yield losses. Losses in a susceptible cultivar, Timgalen, varied between 13.9 and 23.9% whereas those in a partially resistant cultivar, 1008 C16, varied between 6.8 and 13.6%.

scholarly journals Herbicide selectivity and weed control in cowpea

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.

scholarly journals INFLUENCE OF FOLIAR APPLICATION OF FUNGICIDES TO CONTROLPHAEOSPHAERIA LEAF SPOT IN MAIZE

2017 ◽  
Vol 26 (4) ◽  
pp. 573-583
Author(s):  
José Roberto Chaves Neto ◽  
Ricardo Boscaini ◽  
Ivan Francisco Dressler da Costa ◽  
Nívea Raquel Ledur ◽  
Renato Carnellosso Guerra ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Foliar Application ◽  
Severity Index ◽  
Crop Productivity ◽  
Grain Weight ◽  
The Other ◽  
Experimental Plot ◽  
Phenological Stage ◽  
Thousand Grain Weight ◽  
Maize Crop

The objective of this study was to evaluate the effectiveness of foliar application of fungicides to control Phaeosphaeria leaf spot and consequently on the features of the maize crop productivity in the crop year 2014/15. The experimental design was randomized blocks, in a 2x4 factorial scheme, with two hybrids, three treatments + a control in four replications. The treatments were based on the following fungicides (g i.a L-1): epoxiconazole + pyraclostrobin (333 + 167); cyproconazole + picoxystrobin (80 + 200); azoxystrobin + benzovinliflupyr (300 + 150), which were applied in BG7051H and BG7060HR hybrids with knapsack/ manual sprayer, pressurized with CO2 in the phenological stage of culture V8, 70 days after seeding (70 DAS). The experimental plot had four rows spaced at 0.50 m and length of 10.0 m, resulting in a total area of 20 m2 and useful area of 8 m2, which held the white spot severity assessments, grain yield (kg ha-1) and thousand grain weight (g). Significant differences were observed for all fungicides compared to the control. The control alone had the highest severity index compared to the other treatments. Regarding the thousand grain weight and productivity (kg ha-1), the azoxystrobin + solatenol treatment was superior to the control and other treatments with fungicides, with a higher production of grain compared to the control.

scholarly journals Effect of Selected Weed Management Practices on the Growth and Yield Components of Finger Millet (Eleusine coracana) in Western Region of Kenya

2021 ◽  
pp. 1-9
Author(s):  
Mayaka Justus Mogaka ◽  
Korir Kibet Nicholas ◽  
Wafula Wekha Nelson ◽  
Joseph P. Onyango Gweyi
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Yield Components ◽  
Finger Millet ◽  
Management Practices ◽  
Grain Weight ◽  
The Other ◽  
Growth And Yield ◽  
Weed Biomass ◽  
1000 Grain Weight

Finger millet (Elusine coracana) accounts for 8% of the total area and 11% of the millet production worldwide.  It is grown on over 4 million ha globally, mainly for food purposes. Millions of people in the dry lands of Central and East Africa, and South of India depend on finger millet as an important source of food to them (CGIAR, 2001). Finger millet is one of the most neglected and underutilized crops. Additionally, the crop has received limited research attention compared to wheat, rice, and maize (FAO, 2011). Therefore, production challenges such as those caused by weeds like goose grass Elusine indica remain at large. Manual weeding is the commonly employed weed control method in finger millet production, but is expensive and labour intensive. The current study was set to evaluate the influence of weed management practices on finger millet growth and yield components. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replicates. The plots measured 2 by 2m with a border width of 1m. The treatments included Pendimethalin, Dimethyl amine, Metolachlor, Metribuzin, Atrazine (at three rates each 1.0, 1.5 and 2.0 l/ha), No weeding and Hand weeding. Data was collected on the number of weed species, weed biomass, number of basal tillers, herbicide phytotoxicity, weed and crop heights, number of panicles, weight of panicles, weight of un-threshed and threshed grains and 1000 grain weight. Data was analyzed using one-way ANOVA using GenStat version 15.1. Application of Pendimethalin at 1.5 and 2.0 L/ha Active Ingredient (AI), resulted in weed optimal control and least phytotoxicity. Results also indicated that the height of finger millet was significantly (p<0.001) higher where the herbicides were applied. Lower weed biomass was also positively correlated with higher crop height, more panicles, high unthreshed and threshed weights and a 1000 grain weight. Application of 2,4D at rates of 1.5L and 2.0L resulted in significantly taller plants 33.00 cm, than the other weed management methods. Finger millet under Pendimethalin 1.5 L gave the highest number of 86 panicles while Atrazine 2.0L and Pendimethalin1.5L methods of weed control, had significantly higher weight compared to all the other treatments. The 1000 seed mass across the treatments averaged 2.31 g while the on the untreated treatments had an average of 1.54 g. Weed control using pre emergence herbicides significantly (p<0.001) increased the yields of finger millet.

scholarly journals Diminishing weed control exacerbates maize yield loss to adverse weather

2021 ◽  
Author(s):  
Christopher A. Landau ◽  
Aaron G. Hager ◽  
Martin M. Williams
Keyword(s):  
Weed Control ◽  
Yield Loss ◽  
Maize Yield ◽  
Adverse Weather
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