scholarly journals Insecticide Seed Treatments Partially Safen Rice to Low Rates of Glyphosate and Imazethapyr

2018 ◽  
Vol 32 (5) ◽  
pp. 520-525
Author(s):  
Steven M. Martin ◽  
Jason K. Norsworthy ◽  
Robert C. Scott ◽  
Jarrod Hardke ◽  
Gus M. Lorenz ◽  
...  

AbstractEach year there are multiple reports of drift occurrences, and the majority of drift complaints in rice are from imazethapyr or glyphosate. In 2014 and 2015, multiple field experiments were conducted near Stuttgart, AR, and near Lonoke, AR, to evaluate whether insecticide seed treatments would reduce injury from glyphosate or imazethapyr drift or decrease the recovery time following exposure to a low rate of these herbicides. Study I was referred to as the “seed treatment study,” and Study II was the “drift timing study.” In the seed treatment study the conventional rice cultivar ‘Roy J’ was planted, and herbicide treatments included imazethapyr at 10.5 g ai ha–1, glyphosate at 126 g ae ha–1, or no herbicide. Each plot had either a seed treatment of thiamethoxam, clothianidin, chlorantraniliprole, or no insecticide seed treatment. The herbicides were applied at the two- to three-leaf growth stage. Crop injury was assessed 1, 3, and 5 wk after application. Averaged over site-years, thiamethoxam-treated rice had less injury than rice with no insecticide seed treatment at each rating, along with an increased yield. Clothianidin-treated rice had an increased yield over no insecticide seed treatment, but the reduction in injury for both herbicides was less pronounced than in the thiamethoxam-treated plots. Overall, chlorantraniliprole was generally the least effective of the three insecticides in reducing injury from either herbicide and in protecting rice yield potential. A second experiment conducted at Stuttgart, AR, was meant to determine whether damage to rice from glyphosate and imazethapyr was influenced by the timing (15, 30, and 45 d after planting) of exposure to herbicides for thiamethoxam-treated and nontreated rice. There was an overall reduction in injury with the use of thiamethoxam, but the reduction in injury was not dependent on the timing of the drift event. Reduction in damage from physical drift of glyphosate and imazethapyr as well as increased yields over the absence of an insecticide seed treatment appear to be an added benefit.

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
M. R. Miller ◽  
R. C. Scott ◽  
G. Lorenz ◽  
J. Hardke ◽  
J. K. Norsworthy

Field experiments were conducted in 2013 and 2014 to evaluate the effect of insecticide seed treatments on exposure of young conventional rice to reduced rates of glyphosate and imazethapyr. During the two-year study, “Roy J” rice seed was treated with CruiserMaxx® Rice, thiamethoxam plus fungicide, or a fungicide-only treatment. Subsequently, glyphosate (Roundup PowerMax®) at 39.42, 78.76, or 157.54 g ae/ha or imazethapyr (Newpath®) at 4.39, 8.74, or 17.49 g ai/ha was applied at the 2- to 3-leaf growth stage of rice. Results in 2013 indicated that rice plants from seed treated with CruiserMaxx Rice exhibited significantly less injury 1, 3, and 6 weeks after either imazethapyr or glyphosate was applied in comparison to the plants having fungicide-only treated seed. The addition of an insecticide seed treatment also resulted in higher yields when both herbicides were applied compared to the fungicide-only seed treatment receiving the same herbicide treatments. In 2014, an overall decrease in injury from both herbicides was observed when rice seed was treated with CruiserMaxx Rice compared to receiving a fungicide-only seed treatment. Significant yield loss from low rates of glyphosate or imazethapyr was not observed in 2014, with or without a seed treatment. Based on the positive effects observed from the CruiserMaxx Rice seed treatment in reducing injury and maintaining rice yields, the insecticide seed treatment appears to provide some safening to rice against low rates of glyphosate and imazethapyr.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1469
Author(s):  
Silke Deketelaere ◽  
Katrijn Spiessens ◽  
Sabien Pollet ◽  
Lien Tyvaert ◽  
Luc De Rooster ◽  
...  

Verticillium wilt is one of the most important diseases of cauliflower and can lead to serious economic losses. In this study, two complementary strategies were explored to employ the antagonistic capacity of Verticillium isaacii towards Verticillium wilt of cauliflower. The first strategy focused on introducing V. isaacii Vt305 by artificial inoculation of cauliflower plantlets at the nursery stage. Two inoculum types (spores and microsclerotia of V. isaacii Vt305) and different concentrations of microsclerotia were tested in greenhouse and field trials. Seed treatment with 500 microsclerotia seed−1 led to a satisfying biocontrol level of Verticillium wilt. In addition, the PHYTO-DRIP® system was successful in delivering the microsclerotia to cauliflower seeds. The second strategy relied on the stimulation of the natural V. isaacii populations by rotating cauliflower with green manures and potato. Four green manure crops and potato were tested during multiple field experiments. Although these crops seemed to stimulate the V. isaacii soil population, this increase did not result in a control effect on Verticillium wilt of cauliflower in the short term. Importantly, our results indicate that the use of green manures is compatible with the application of V. isaacii Vt305 as biocontrol agent of Verticillium wilt in cauliflower.


Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 683-689 ◽  
Author(s):  
Leopoldo E. Estorninos ◽  
David R. Gealy ◽  
Edward E. Gbur ◽  
Ronald E. Talbert ◽  
Marilyn R. McClelland

Red rice, which grows taller and produces more tillers than domestic rice and shatters most of its seeds early, is a major weed in many rice-growing areas of the world. Field experiments were conducted at Stuttgart, AR in 1997 and 1998 to evaluate the growth response of the Kaybonnet (KBNT) rice cultivar to various population densities of three red rice ecotypes. The ecotypes tested were Louisiana3 (LA3), Stuttgart strawhull (Stgstraw), and Katy red rice (KatyRR). Compared with KBNT alone, LA3, the tallest of the three red rice ecotypes, reduced tiller density of KBNT 51%, aboveground biomass at 91 d after emergence (DAE) 35%, and yield 80%. Stgstraw, a medium-height red rice, reduced KBNT tiller density 49%, aboveground biomass 26%, and yield 61%. KatyRR, the shortest red rice, reduced KBNT tiller density 30%, aboveground biomass 16%, and yield 21%. Tiller density of rice was reduced by 20 to 48% when red rice density increased from 25 to 51 plants m−2. Rice biomass at 91 DAE was reduced by 9 and 44% when red rice densities were 16 and 51 plants m−2. Rice yield was reduced by 60 and 70% at red rice densities of 25 and 51 plants m−2, respectively. These results demonstrate that low populations of red rice can greatly reduce rice growth and yield and that short-statured red rice types may affect rice growth less than taller ecotypes.


Author(s):  
José Eduardo Minussi Winck ◽  
Thomas Newton Martin ◽  
Marlo Adriano Bison Pinto ◽  
Lucas Allan Bruning ◽  
Guilherme de Almeida Arismendi

This study aimed at determining the effect of a variety of plants arrangements on foliar growth and development as well as the productive potential in soybean. The field experiments were performed over two agricultural years (2015/16 and 2016/17) on Argisoil in subtropical environment. The two selected cultivars, viz., BMX Tornado RR and FPS Urano RR were sown in four spatial distribution of the plants such as conventional spacing (0.45 m spacing between rows), reduced spacing (0.225 m spacing between rows), paired spacing (two rows with 0.225 m and 0.45 m spacing from the other rows) and crossed spacing (0.45 m spacing between the rows with crosses of two rows, at a 90° angle). The randomized block design was adopted for the experiments with the treatments in a 2x4 factorial distribution and four replications. The first factor was the cultivar and the second types of plant distribution. The results showed that plant arrangement affected the plant profile regarding the behavior of the ecophysiological variables like plastochron, leaf lifetime and yield distribution. Leaf life in each stratum was caused by the foliar senescence rhythm, explained by a 4th degree polynomial model, revealing two peaks in the senescence rate, one during pre-flowering stage and the other when the grain filling stage was completed. According to the results, we do not recommend changes in conventional spacing.


2019 ◽  
Vol 20 (3) ◽  
pp. 160-164
Author(s):  
Sudha GC Upadhaya ◽  
Venkataramana Chapara ◽  
Mukhlesur Rahman ◽  
Luis E. del Río Mendoza

The efficacy of five fungicide seed treatments as a management tool against blackleg on spring canola was evaluated under greenhouse and field conditions in North Dakota. Blackleg, caused by Leptosphaeria maculans, inflicts the greatest yield losses when infecting seedlings before they reach the six-leaf growth stage. In greenhouse studies, 10-day-old seedlings were inoculated with L. maculans spore suspensions and evaluated 12 days later and at maturity or inoculated 12, 20, or 28 days after planting and evaluated at maturity. In field trials conducted in 2017 and 2018, severity was assessed at maturity. In the greenhouse, all fungicide seed treatments reduced (P = 0.05) disease severity at the seedling stage, but only the protection provided by Obvius (fluxapyroxad + pyraclostrobin + metalaxyl) and Helix Vibrance (mefenoxam + fludioxonil + sedaxane + difenoconazole + thiamethoxam) reduced (P < 0.05) severity at the adult stage; however, none of them provide effective protection when plants were inoculated 20 days after planting or later. In field trials, none of the treatments significantly (P > 0.05) improved plant stand and yield or reduced disease incidence and severity. Although fungicide seed treatment is a valuable tool, it should not be used as the only method to manage blackleg disease.


Author(s):  
Daniel G. Cerritos-Garcia ◽  
Juan P. Granda ◽  
Rashelle Matthiessen ◽  
Brian W. Diers ◽  
Alison E. Robertson ◽  
...  

Phytophthora root and stem rot (PRR) is a limiting factor for soybean production. Seed treatments are used for early-season management, but efficacy can depend on seed selection and the local environment. Ethaboxam is a new fungicide commercially available as a seed treatment to control oomycetes. Field experiments were established in Illinois and Iowa in 2017 and 2018 to evaluate the effect of ethaboxam + metalaxyl on PRR. Experiments included soybean lines with no resistance gene, Rps1c or Rps1k, and different levels of partial resistance. Seed treatments increased soybean stands in all locations and years. Significant yield effects were observed only in two locations that were inoculated with Phytophthora spp. Groups of soybean lines with the same Rps gene responded differently in each location, showing how Rps gene usefulness depends on the field. A comparison of the effect of seed treatment on lines with different levels of partial resistance showed that partial resistance alone cannot always protect against stand losses. Soybean lines with high levels of partial resistance had consistently higher yields than those with low levels of partial resistance across Illinois locations. These results show that ethaboxam seed treatment can protect early-season stands and that selection of cultivars with high levels of partial resistance is important for PRR management.


2018 ◽  
Vol 32 (5) ◽  
pp. 570-578
Author(s):  
Blake R. Barlow ◽  
Lovreet S. Shergill ◽  
Mandy D. Bish ◽  
Kevin W. Bradley

AbstractField experiments were performed in 2016 and 2017 in Missouri to determine whether interactions exist between PRE herbicides and seed treatments in soybean. The experiments consisted of a randomized complete block design with factorial arrangements of varieties, seed treatments, and herbicides. We selected two genetically similar varieties of soybean, one with known tolerance to PPO-inhibiting herbicides and one with known sensitivity. Each variety of seed received three separate seed treatment mixtures (STMs): (1) STM1, imidacloprid plus prothioconazol+penflufen+metalaxyl plus metalaxyl plusBacillus subtilis+B. pumilis, (2) STM2,Pasteuria nishizawaeplus thiamethoxam plus prothioconazol+penflufen+metalaxyl plus metalaxyl plusB. subtilis+B. pumilis, and (3) STM3, fluopyram plus imidacloprid plus prothioconazol+penflufen+metalaxyl plus metalaxyl plusB. subtilis+B. pumilis. Chlorimuron-ethyl+flumioxazin+pyroxasulfone, chlorimuron-ethyl+flumioxazin+metribuzin, and chlorimuron-ethyl+sulfentrazone were applied PRE to each variety and seed treatment combination at 1× and 2× the labeled use rate. Chlorimuron-ethyl+sulfentrazone treatment at the 2× rate resulted in greater injury of 8% and 14% to the sensitive variety than the tolerant in 2016 and 2017, respectively; this was the highest injury observed from any herbicide treatment in either year. In 2017, chlorimuron-ethyl+sulfentrazone resulted in the greatest height reductions in both varieties, but this reduction was more evident in the sensitive (19%) than in the tolerant (6%) variety. Overall, yield differences between the two varieties were not consistent between years, and for both varieties, the sulfentrazone-containing treatments resulted in the highest yield losses. The results of this research indicate that there is a larger interaction between herbicides and varieties than there is between herbicides and seed treatments, or seed treatments and varieties.


1988 ◽  
Vol 2 (3) ◽  
pp. 310-316 ◽  
Author(s):  
Joel K. Ransom ◽  
Ervin A. Oelke

Field experiments were conducted to evaluate the effect of application time on common waterplantain control in wild rice with MCPA and 2,4-D. Common waterplantain control was greatest when MCPA or 2,4-D were applied at 1.1 or 1.7 kg ai/ha at the two-aerial leaf stage. The best late-season control was MCPA applied at the scape elongation growth stage. Common waterplantain was controlled adequately when 0.6 to 0.8 kg/ha of MCPA were applied at the scape elongation or early flowering stage. However, because of common water plantain interference and sensitivity of wild rice to late herbicide applications, the best treatment stage for wild rice yield was when MCPA was applied at 0.6 kg/ha to common waterplantain at the two-aerial leaf stage. Wild rice at this time is at the more tolerant one-aerial leaf growth stage.


2005 ◽  
Vol 19 (2) ◽  
pp. 312-318 ◽  
Author(s):  
Joseph H. Pankey ◽  
James L. Griffin ◽  
Patrick D. Colyer ◽  
Raymond W. Schneider ◽  
Donnie K. Miller

Field experiments were conducted to evaluate the influence of preemergence (PRE) herbicides metolachlor at 1,700 g ai/ha, pyrithiobac at 70 g ai/ha, or pendimethalin at 840 g ai/ha applied alone or with fluometuron at 1,300 g ai/ha and glyphosate postemergence (POST) at 840 g ai/ha on seedling diseases in glyphosate-resistant cotton. Hypocotyl disease severity both years averaged across PRE herbicide treatments was greater after glyphosate application to four-leaf cotton than cotyledon cotton. The PRE herbicide treatments, particularly those including fluometuron, increased root and hypocotyl disease ratings compared with a nontreated control, and a sequential application of glyphosate did not further increase disease severity. Greenhouse experiments using soil infested withRhizoctonia solaniconfirmed findings from the field study showing that PRE herbicides can predispose cotton to greater seedling disease injury with no increased seedling disease severity associated with application of glyphosate. In the field study, glyphosate applied at cotyledon or four-leaf growth stages decreased disease severity on cotton hypocotyls both years. This inhibitory effect of glyphosate was less evident in the greenhouse study and may have been related to species of fungi present, infestation level, and differences in environmental conditions when compared with the field.


Weed Science ◽  
1994 ◽  
Vol 42 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Charles E. Snipes ◽  
J. D. Byrd

Field experiments conducted from 1987 through 1991 at the Delta Branch Experiment Station, Stoneville, MS, determined the effect of postemergence topical applications of fluometuron and MSMA on cotton yield and fruiting. Herbicide treatments applied to cotton in the cotyledon to 1-leaf growth stage were 1.12 kg ai ha-1fluometuron plus 0.25% by vol nonionic surfactant, 2.2 kg ai ha-1MSMA, and a combination of 1.12 kg ha-1fluometuron and 2.24 kg ha-1MSMA. The commercial formulation of MSMA contained nonionic surfactant. Visual injury of cotton 14 d after treatment ranged from 14 to 28% for fluometuron, 9 to 26% for MSMA, and 22 to 34% for the combination. Seed cotton yield at the first harvest was reduced by all herbicide treatments except in 1987 and for DES 119 cotton in 1990. In 1990, yield of DES 119 cotton treated with MSMA and the combination was less than the untreated control for the second harvest interval. Cotton yield from herbicide treatments at later harvests was equal to or greater than the untreated control. Only in 1988 did all treatments reduce total seed cotton yield below the untreated control. Fiber quality was not adversely affected by the herbicides. Compared to the control, plant mapping indicated that the number of sympodial branches per plant was reduced by MSMA and by the combination for DPL 50 cotton in 1990. Averaged over 4 experiment years, herbicide treatments did not reduce total bolls per plant; percentage of bolls in first, second, or outer positions; highest sympodium with two bolls; or number of sympodium with bolls in the first or second position. However, MSMA and the combination increased node number of the first sympodia by one and 1.5 positions, respectively, when compared to the control, indicating delayed maturity.


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