Characterization of carinata tolerance to select herbicides using field dose-response studies

2021 ◽  
pp. 1-26
Author(s):  
Sandra R. Ethridge ◽  
Angela Post ◽  
Pratap Devkota ◽  
Michael J. Mulvaney ◽  
Ramon G. Leon

Abstract Field experiments were conducted from 2017 to 2019 to determine the tolerance of carinata to several preemergence and postemergence herbicides. Preliminary screenings identified herbicides which caused large variation on carinata injury, indicating the potential for selectivity. Dose-response field studies were conducted to quantify the tolerance of carinata to select herbicides. Diuron applied preemergence at rates of 280 g ai ha−1 or above reduced carinata population density 54% to 84% compared to the nontreated control. In certain locations, clomazone applied preemergence caused minor injury with an acceptable level of carinata tolerance and only doses above 105 g ai ha−1 caused yield reductions. Napropamide doses of 2,856 g ai ha−1 or higher applied preemergence caused at least 25% injury to carinata; however, the damage was not severe enough to reduce yields. Simazine applied postemergence at rates above 1,594 g ai ha−1 caused 50% or more injury, resulting in yield losses ranging from 0 to 95% depending on location. Clopyralid applied postemergence at 2,512 g ai ha−1 caused 25% injury with relative yield reductions which varied across locations. The present study identified clomazone and napropamide applied preemergence, and clopyralid applied postemergence as potential herbicides for weed control in carinata. In contrast, diuron, simazine, metribuzin, imazethapyr, and chlorimuron caused high levels of carinata mortality and can be used to control volunteer carinata plants in rotational crops.

1970 ◽  
Vol 6 ◽  
pp. 73-77
Author(s):  
Bishnu K Gyawali

Yield loss in soybean due to leaf roller (Apoderus cyaneus Hope) was studied at Khumaltarduring 1985 and 1986 seasons. Field experiments were conducted during vegetative as well asreproductive stages of soybean. Rolled leaves of soybean with eggs, grubs and pupae werecollected from the field and reared in the laboratory for adults. Adults were introduced intonylon cages installed at the central rows of each plot just after germination of soybean. Insectswere maintained at population density of 25, 50 and 100 per m2density, the potential grain yield loss of cultivar, Ransom soybean in its vegetative andreproductive stages were 103 and 48 mg per day respectively from each adult of A. cyaneus.Percentages of yield losses were 36.2, 45.2, and 58.0 during vegetative and 37.5, 48.5 and 66.0during reproductive stages from the insect population of 25, 50 and 100, respectively which, wasnot in accordance with the level of two and four fold increased population density of insect.Yield reduction was higher (260 and 108 mg per day) from each adult beetle at lower populationlevel (25) in both vegetative and reproductive stages of soybean.Key words: Economic threshold level; leaf roller; physiological growth stages; yield lossDOI: 10.3126/narj.v6i0.3367Nepal Agriculture Research Journal Vol.6 2005 pp.73-77


Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 369-379 ◽  
Author(s):  
Seth A. Strom ◽  
Lisa C. Gonzini ◽  
Charlie Mitsdarfer ◽  
Adam S. Davis ◽  
Dean E. Riechers ◽  
...  

AbstractField experiments were conducted in 2016 and 2017 in Champaign County, IL, to study a waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer] population (CHR) resistant to 2,4-D and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-, photosystem II–, acetolactate synthase (ALS)-, and protoporphyrinogen oxidase–inhibiting herbicides. Two field experiments were designed to investigate the efficacy of very-long-chain fatty-acid (VLCFA)-inhibiting herbicides, including a comparison of active ingredients at labeled use rates and a rate titration experiment. Amaranthus tuberculatus density and control were evaluated at 28 and 42 d after treatment (DAT). Nonencapsulated acetochlor, alachlor, and pyroxasulfone provided the greatest PRE control of CHR (56% to 75%) at 28 DAT, while metolachlor, S-metolachlor, dimethenamid-P, and encapsulated acetochlor provided less than 27% control. In the rate titration study, nonencapsulated acetochlor controlled CHR more than equivalent field use rates of S-metolachlor. Subsequent dose–response experiments with acetochlor, S-metolachlor, dimethenamid-P, and pyroxasulfone in the greenhouse included three multiple herbicide–resistant (MHR) A. tuberculatus populations: CHR-M6 (progeny generated from CHR), MCR-NH40 (progeny generated from Mclean County, IL), and ACR (Adams County, IL), in comparison with a sensitive population (WUS). Both CHR-M6 and MCR-NH40 are MHR to atrazine and HPPD, and ALS inhibitors and demonstrated higher survival rates (LD50) to S-metolachlor, acetochlor, dimethenamid-P, or pyroxasulfone than ACR (atrazine resistant but HPPD-inhibitor sensitive) and WUS. Based on biomass reduction (GR50), resistant to sensitive (R:S) ratios between CHR-M6 and WUS were 7.5, 6.1, 5.5, and 2.9 for S-metolachlor, acetochlor, dimethenamid-P, and pyroxasulfone, respectively. Values were greater for MCR-NH40 than CHR-M6, and ACR was the most sensitive to all VLCFA inhibitors tested. Complete control of all populations was achieved at or below a field use rate of acetochlor. In summary, field studies demonstrated CHR is not controlled by several VLCFA-inhibiting herbicides. Greenhouse dose–response experiments corroborated field results and generated R:S ratios (LD50) ranging from 4.5 to 64 for CHR-M6 and MCR-NH40 among the four VLCFA-inhibiting herbicides evaluated.


2017 ◽  
Vol 31 (6) ◽  
pp. 877-882 ◽  
Author(s):  
Ramon G. Leon ◽  
Jason A. Ferrell ◽  
Michael J. Mulvaney

Carinata is a new biofuel crop that was recently introduced in the southeastern USA as a winter crop. This crop is competitive after canopy closure, but there is a need for weed control options at earlier growth stages. Field experiments were conducted from 2014 to 2016 to determine the safety of several PRE and POST herbicides in carinata. Pendimethalin at 1080 g ai ha−1 applied preplant incorporated (PPI) and PRE caused no carinata injury, or plant density and yield reductions. S-metolachlor was also safe at 694, 1070, 1390, and 2780 g ai ha−1 applied at PRE, 3 d after planting (DAP) and at the 2- to 6-leaf stage. Flumioxazin at 72 g ai ha−1 applied PRE was highly injurious on carinata preventing its establishment. Among the POST herbicides evaluated, clopyralid at 210 g ae ha1 and clethodim at 136 g ai ha−1 caused minor injury to carinata but did not reduce yield compared to the nontreated control. Acifluorfen at 420 g ai ha−1, bentazon at 840 g ai ha−1, and carfentrazone at 18 g ai ha−1 applied POST to carinata caused 75 to 100% injury. Under stressful conditions (i.e. high summer temperatures) all POST herbicides caused more injury than under more favorable conditions for growth in Florida (i.e. winter). The present study identified pendimethalin, S-metolachlor, clopyralid and clethodim as potential herbicides for weed control in carinata, and flumioxazin, acifluorfen, bentazon, and carfentrazone as herbicides that can be used to control volunteer carinata plants in rotational crops.


Weed Science ◽  
2016 ◽  
Vol 64 (2) ◽  
pp. 348-360 ◽  
Author(s):  
Evgenia Dor ◽  
Evgeny Smirnov ◽  
Shmuel Galili ◽  
Achdary Guy ◽  
Joseph Hershenhorn

The tomato mutant line HRT was obtained by ethyl methanesulfonate seed mutagenesis of the commercial tomato line M82. Greenhouse studies were conducted to determine whole-plant response to the imidazolinone herbicides imazamox, imazapic, and imazapyr; pyrithiobac-sodium (a herbicide from the pyrimidinylthiobenzoic acid group); and propoxycarbazone sodium (sulfonylaminocarbonyltriazolinone group). The mutant was highly resistant to imazamox, imazapic, and imazapyr, but did not differ from M82 in its response to the sulfonylurea herbicides Envoke (trifloxysulfuron), Monitor (sulfosulfuron), and Glean (chlorsulfuron). Equip (foramsulfuron), a sulfonylurea herbicide, was toxic to M82 but less so to HRT plants. Under field conditions, HRT showed high resistance to imazapic and imazapyr. The herbicides at a rate of 144 g ai ha−1did not cause any reduction in HRT plant vigor, development, or yield. Results of greenhouse and field experiments demonstrated high Egyptian broomrape–control efficacy with the imidazolinone herbicides imazapic and imazapyr. Two imazapic applications of 9.6 or 14.4 g ai ha−1and three applications of 4.8 g ai ha−1in pot experiments completely prevented appearance of broomrape shoots aboveground. Three and four applications of the same herbicides in the field at a rate of 12 or 24 g ai ha−1completely prevented shoot appearance without any yield losses. Single imazapic application as high as 144 g ai ha−1did not damage the plants or reduce HRT yield.


2019 ◽  
Vol 99 (3) ◽  
pp. 364-370
Author(s):  
Lauren Benoit ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Peter H. Sikkema

Waterhemp is a competitive, summer annual, broadleaf weed that poses a considerable threat to Ontario grain farmers. Populations with multiple resistance to Group 2 (ALS-inhibitors), Group 5 (photosystem II inhibitors), and Group 9 (EPSPS inhibitors) herbicides have been confirmed in Ontario. If left uncontrolled, waterhemp competition can result in corn yield losses of up to 74%. The objective of this research was to evaluate preemergence (PRE) and postemergence (POST) herbicides for control of multiple-herbicide resistant (MR) waterhemp. Two field studies at two locations (Cottam and Walpole Island) were conducted in 2016 and 2017. Fifteen PRE and 12 POST herbicides were evaluated for waterhemp control, density, and aboveground biomass and corn yield. At 8 wk after application (WAA), S-metolachlor/mesotrione/atrazine (1393/139/524 g a.i. ha−1) and S-metolachlor/mesotrione/bicyclopyrone/atrazine (1259/140/35/588 g a.i. ha−1) applied PRE were the most efficacious, controlling MR waterhemp 87% and 91%, respectively. At 8 WAA, the most efficacious POST herbicides were mesotrione + atrazine and dicamba/atrazine, controlling MR waterhemp 92% and 87%, respectively. Reduced waterhemp interference with the PRE herbicides evaluated resulted in corn yield that was similar to the weed-free control.


Weed Science ◽  
2014 ◽  
Vol 62 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Macrina Pérez-López ◽  
Fidel González-Torralva ◽  
Hugo Cruz-Hipólito ◽  
Francisco Santos ◽  
José A. Domínguez-Valenzuela ◽  
...  

Field, greenhouse, and laboratory experiments were conducted to investigate resistance to glyphosate in tropical sprangletop biotypes (Lv8 and Lv9) collected in Persian lime from Veracruz, Mexico. Assays to determine the dose required to reduce seedling fresh weight by 50% indicated a resistance factor (RF) of 4.9 and 3.2 for biotypes Lv8 and Lv9, respectively; whereas the LD50showed a RF of 4.4 and 3.3 for biotypes Lv8 and Lv9, respectively. On the other hand, the RFs using whole plant dose–response assays were lower (RF of 3 for Lv8 and 2.3 for Lv9). The susceptible biotype (LvS) accumulated 5.5 and 11.8 times more shikimate than biotypes Lv8 and Lv9, respectively, at 96 h after treatment (HAT). In field experiments, alternatives to glyphosate-resistant tropical sprangletop management were identified. Indaziflam + glufosinate and paraquat + diuron provided over 80% control of in-field populations of tropical sprangletop at 60 d after treatment (DAT). These results confirmed the first reported case of glyphosate-resistant tropical sprangletop.


2013 ◽  
Vol 93 (6) ◽  
pp. 1187-1193 ◽  
Author(s):  
Holly P. Byker ◽  
Nader Soltani ◽  
Darren E. Robinson ◽  
François J. Tardif ◽  
Mark B. Lawton ◽  
...  

Byker, H. P., Soltani, N., Robinson, D. E., Tardif, F. J., Lawton, M. B. and Sikkema, P. H. 2013. Glyphosate-resistant Canada fleabane [ Conyza canadensis (L). Cronq.]: Dose response to glyphosate and control with postemergence herbicides in soybean in Ontario. Can. J. Plant Sci. 93: 1187–1193. Glyphosate-resistant (GR) Canada fleabane was first reported in Ontario in 2010. Twelve field studies were conducted over a 2-yr period (2011, 2012) to determine the biologically effective dose of glyphosate in the field and to determine the efficacy of postemergence herbicides for control of GR Canada fleabane. A dose between 1271 and 5652 g a.e. ha−1 was required for a 50% reduction in Canada fleabane biomass depending on site and year. To achieve acceptable (>95%) control with glyphosate, 18 840 to 43 200 g a.e. ha−1 of glyphosate was required across all sites. Therefore application of glyphosate at these doses for acceptable (>95%) control is not economical. None of the postemergence herbicides labeled for use in soybean provided acceptable (>95%) control, with cloransulam providing the greatest control (67%) 4 wk after application. Therefore, GR Canada fleabane must be controlled prior to soybean emergence as current herbicides registered in soybean for postemergence use do not provide sufficient control to prevent soybean yield loss.


2019 ◽  
Author(s):  
Nicola Sasanelli ◽  
◽  
Ion Toderas ◽  
Elena Iurcu-Straistaru ◽  
Stefan Rusu ◽  
...  

Curves for graphical estimation of yield losses caused by plant parasitic nematodes were calculated on the basis of the relationship between soil nematode population density and damage to plants as described by the Seinhort’s equation y = m + (1 – m) z(P-T). By a logarithmic transformation this equation was transformed as y = m + (1 – m) 1.05[(P/-T) + 1] and solved considering values of tolerance limit (T) and the minimum relative yield (m) from the literature. The obtained curves that can be defined “Curves of nematode-pathogenicity” allow a quick and easy evaluation of yield losses for each known crop-nematode relationship.


2016 ◽  
Vol 17 (2) ◽  
pp. 95-100 ◽  
Author(s):  
K. L. Bowen ◽  
A. K. Hagan ◽  
M. Pegues ◽  
J. Jones

Crown rust is a common disease on winter oats in Alabama. While considered the most destructive disease of oats, little has been done in recent years, with current cultivars, to demonstrate yield losses due to crown rust. Field studies were conducted to determine the effect of fungicides and application timing on crown rust severity and yield. All fungicides reduced crown rust and improved yield. Two fungicide applications were better than a single fungicide application for reducing crown rust. Relative to yield, a single fungicide application during flag leaf development (FS 8-9) was better than a single application during head extension (FS 10.3). When compared with the non-treated control, significant yield gains were obtained with Tilt and Headline in all four years and Stratego YLD in three of four years. Fungicide programs resulted in a broad range of crown rust severities; disease levels were highly related to decreases in yield in each of four years. In two study years, ‘Coker 227’ was more damaged by crown rust, with about 10% yield loss for each unit disease, than was ‘Horizon 270,’ with 2.5 to 4.5% loss. However, in 2013, virulence patterns of the crown rust pathogen shifted and disease on Horizon 270 was greater than that on Coker 227; relative yield losses were also much lower in 2013. Accepted for publication 15 April 2016. Published 4 May 2016.


2014 ◽  
Vol 28 (2) ◽  
pp. 385-394 ◽  
Author(s):  
Ramon G. Leon ◽  
J. Bryan Unruh ◽  
Barry J. Brecke ◽  
Kevin E. Kenworthy

POST control of grass weed species and contaminant turfgrass species, such as common and hybrid bermudagrass, is a major challenge in zoysiagrass. Fluazifop-P-butyl is a POST herbicide that can provide selective grass weed control with limited injury to zoysiagrass. However, because of the extent of genetic variation among zoysiagrass cultivars, it was proposed that fluazifop-P-butyl tolerance was cultivar dependent. Dose–response field studies were conducted in Jay, FL, in 2012 and 2013, evaluating the tolerance of 11 commercial zoysiagrass cultivars and common bermudagrass to 0, 44, 88, 131, 175, and 263 g ai ha−1of fluazifop-P-butyl. ‘Empire' and ‘Meyer' zoysiagrass were injured 30% or less at 2 wk after treatment (WAT) when treated with 131 g ha−1of fluazifop-P-butyl or less. Conversely, ‘Zeon' and ‘PristineFlora' reached from 30 to more than 50% injury between 2 and 4 WAT with 44 and 88 g ha−1fluazifop-P-butyl. ‘Geo', ‘Crowne', ‘JaMur', and ‘UltimateFlora' showed intermediate injury (i.e. ≤ 60% with 175 and 264 g ha−1) and a recovery period longer than 4 WAT. ‘Emerald', ‘Palisades', and ‘Royal' also showed intermediate injury (i.e., 30 to 65% with 175 and 264 g ha−1), which peaked at 2 WAT and then rapidly declined below 25% injury at 4 WAT. By 8 WAT, all zoysiagrass cultivars had recovered, and no injury was observed. Results from a greenhouse experiment demonstrated that differences observed in the field were cultivar related, especially for the lower tolerance level observed in Zeon and PristineFlora. There is potential to increase fluazifop-P-butyl tolerance in zoysiagrass because of the observed variation among 80 zoysiagrass breeding lines.


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