Phytotoxicity of Flumetsulam on Peanut (Arachis hypogaea)

1996 ◽  
Vol 10 (3) ◽  
pp. 481-487 ◽  
Author(s):  
W. Carroll Johnson ◽  
Benjamin G. Mullinix

Field studies were conducted at Tifton, GA to quantify phytotoxicity of flumetsulam on peanut as influenced by application rate and timing in a weed free experiment. Flumetsulam PPI at rates up to 0.14 kg ai/ha visibly injured peanut and reduced canopy width, but injury from PPI flumetsulam at 0.07 kg/ha or less was no worse than a standard early postemergence (EPOST) treatment of bentazon (0.6 kg ai/ha) plus paraquat (0.14 kg ai/ha). Flumetsulam EPOST at rates up to 0.07 kg/ha visibly injured peanut and reduced peanut canopy width. Flumetsulam injury at rates of 0.035 kg/ha EPOST was similar to that caused by bentazon plus paraquat. Interactive effects of PPI and EPOST flumetsulam reduced early and mid-season pod and foliage biomass more than either application alone. However, peanut recovered with final yields not affected by flumetsulam, regardless of rate or time of application.

2001 ◽  
Vol 28 (1) ◽  
pp. 13-19 ◽  
Author(s):  
T. L. Grey ◽  
D. C. Bridges ◽  
E. F. Eastin

Abstract Field studies were conducted from 1996 to 1998 in Georgia to determine peanut (Arachis hypogaea L.) and weed response to ethalfluralin (0.8 kg ai/ha) plus diclosulam applied preplant incorporated (PPI) at 9, 18, 26, 35 and 52 g ai/ha. Other treatments included ethalfluralin PPI followed by paraquat plus bentazon (140 and 280 g ai/ha, respectively) early postemergence (EPOST) applied alone or following ethalfluralin plus diclosulam (18 and 26 g ai/ha) PPI, ethalfluralin PPI followed by imazapic (71 g ai/ha) postemergence (POST), and ethalfluralin PPI. Ethalfluralin was applied PPI in all herbicide programs. Diclosulam controlled Florida beggarweed [Desmodium tortuosum (Sweet) D.C.], sicklepod [Senna obtusifolia (L.) Irwin and Barneby], and yellow nutsedge (Cyperus esculentus L.) inconsistently, and POST application of paraquat plus bentazon was needed for acceptable control. However, diclosulam controlled common ragweed (Ambrosia artemisiifolia L.), tropic croton (Croton glandulosus Muell-Arg.), wild poinsettia (Euphorbia heterophylla L.), and prickly sida (Sida spinosa L.) without the need for POST herbicides. Higher yields were recorded with diclosulam PPI followed by a sequential application of paraquat plus bentazon than herbicide programs not containing diclosulam or diclosulam alone. Diclosulam PPI followed by sequential applications of paraquat plus bentazon provided greater control of sicklepod and prickly sida that resulted in greater yields. Yields from dicosulam PPI followed by paraquat plus bentazon EPOST were equivalent to yields with paraquat plus bentazon EPOST followed by imazapic POST or imazapic EPOST.


1994 ◽  
Vol 8 (4) ◽  
pp. 738-743 ◽  
Author(s):  
W. Carroll Johnson ◽  
Daniel L. Colvin ◽  
Benjamin G. Mullinix

Field studies were conducted at Tifton, GA and Gainesville, FL to quantify the phytotoxicity of endothall formulation, rate, and time of application on peanut in a weed-free experiment. Peanut treated with mono (N,N-dimethylalkylamine) salt of endothall (DMAA endothall) were more necrotic than those treated with dipotassium salt of endothall (DP endothall), though necrosis was temporary. Injury from DMAA endothall at rates of 0.6 to 1.1 kg ai/ha was similar to the standard treatment of bentazon plus paraquat for most parameters. Peanut treated with the highest rate of DMAA endothall (4.5 kg/ha) were more necrotic and took longer to recover than lower rates. The highest rate of DP endothall (4.5 kg ai/ha) stunted peanut more than any DMAA endothall treatment. However, lower rates of DP endothall (0.6 to 2.2 kg/ha) were generally less injurious than DMAA endothall at equivalent rates. Peanut yields were not affected by either formulation of endothall at 0.6 to 1.1 kg/ha, applied from vegetative emergence through 4 wk after emergence.


Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.


2021 ◽  
pp. 154805182098653
Author(s):  
Jonathan C. Ziegert ◽  
David M. Mayer ◽  
Ronald F. Piccolo ◽  
Katrina A. Graham

This research explores the nature of collective leadership by examining the boundary conditions of how and when it relates to unit functioning. Building from a contingency perspective that considers the impact of contextual factors, we propose that collective charismatic leadership will be associated with lowered unit conflict, and this relationship will be strengthened by the contingency elements of individual charismatic leadership, task complexity, and social inclusion. Furthermore, we propose that the interactions of collective charismatic leadership with these contextual factors will relate to performance and satisfaction through conflict. We examine our hypotheses across two unit-level field studies, and the results illustrated that high levels of these contextual factors enhanced the negative relationship between collective charismatic leadership and conflict, which generally mediated the relationships between these interactive effects and performance and satisfaction. The results also highlight the detrimental aspects of collective leadership and how it can relate to reduced unit functioning when it is not aligned with an appropriate context. Overall, these findings begin to provide a more complete picture of collective leadership from a contingency perspective through a greater understanding of when and how it is related to unit functioning.


2021 ◽  
pp. 1-21
Author(s):  
Laurence G. Weinzimmer ◽  
Eric J. Michel ◽  
Jennifer Robin

Abstract Drawing on Wales, Monsen, and McKelvie's (2011, Entrepreneurship Theory and Practice, 35(5), 895–923) model of entrepreneurial orientation pervasiveness and the strong culture hypothesis (Denison, 1984, Organization Dynamics, 13, 4–22), this study investigates how entrepreneurial orientation (EO) strength, defined as the level of agreement in the shared perceptions of EO, serves as a boundary condition of the EO–firm performance relationship. Four field studies provide evidence for a valid and reliable 10-item multidimensional measure of entrepreneurial orientation, the EO-10, which in turn, may be used to assess EO strength. We establish content and construct validity of the EO-10 (study 1; n = 447 employees), criterion-related validity with revenue growth and sales growth (study 2; n = 412 employees in 43 profit centers), and convergent validity with Covin and Slevin's (1989, Strategic Management Journal, 10, 75–87) 9-item measure (study 3; n = 291 employees). Finally, in study 4 (n = 853 employees nested in 22 organizations), we demonstrate the interactive effects of EO and EO strength on profit growth and revenue growth. In sum, this study provides conceptual and empirical evidence for the importance of EO strength as a moderator of the EO–firm performance relationship.


1992 ◽  
Vol 6 (1) ◽  
pp. 108-112 ◽  
Author(s):  
W. James Grichar

Field studies were conducted from 1986 through 1988 to evaluate various herbicides for yellow nutsedge control and peanut yields. Three applications of pyridate provided control comparable to two applications of bentazon with yellow nutsedge regrowth beginning 3 to 4 wk after application depending on moisture conditions. Crop oil concentrate did not improve the activity of pyridate. Flurtamone provided control comparable with that of metolachlor. Nutsedge control with fomesafen was erratic with peanut injury noted. Peanut yields did not reflect the competitive nature of nutsedge.


1991 ◽  
Vol 18 (2) ◽  
pp. 67-71 ◽  
Author(s):  
G. Wehtje ◽  
J. W. Wilcut ◽  
J. A. McGuire ◽  
T. V. Hicks

Abstract Field studies were conducted over a three year period to examine the sensitivity of four peanut (Arachis hypogaea L.) cultivars (Florunner, Sunrunner, Southern runner, and NC 7) to foliar applications of paraquat (1, 1′-dimethyl-4, 4′-bipyridinium ion). Treatments included an untreated control and four herbicide treatments: paraquat applied alone at 0.14 and 0.28 kg/ha, or tank mixed with alachlor [2-chloro-N-(2, 6-diethylphenyl)-N-(methoxymethyl)acetamide] at 4.40 kg/ha. Weeds were hand-removed so that only herbicidal treatments were variables. Paraquat phytotoxicity did not differ between cultivars. No cultivar evaluated was abnormally sensitive nor tolerant to any paraquat-containing treatment. Laboratory studies utilizing radio labelled paraquat revealed that foliar absorption and translocation of paraquat did not vary between peanut cultivars. Yield differences were attributed to differences in yield potential between cultivars.


2012 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
Joao Augusto ◽  
Timothy B. Brenneman

Fungicide penetration of the peanut (Arachis hypogaea) canopy to target soilborne pathogens is difficult due to the dense foliage present when mid- to late-season applications are made. To assess the effect of application timing and volume on leaf spot and stem rot control as well as peanut yield, pyraclostrobin (0.21 kg a.i./ha) or chlorothalonil (1.26 kg a.i./ha), a systemic and a contact fungicide, respectively, were applied four times on cv. Georgia Green during the day (on unfolded leaves) or at night (on folded leaves) at 187, 243, or 355 liters/ha. Night application of pyraclostrobin, across spray volumes, gave the best stem rot control and pod yield increase. Pyraclostrobin applied during the day at higher spray volumes also slightly increased control of stem rot, apparently by improving canopy penetration. Neither application timing nor spray volume affected leaf spot control with pyraclostrobin. Higher spray volumes for the chlorothalonil applications tended to improve control of early and late leaf spot, possibly by increasing coverage of foliage and stems. Accepted for publication 10 January 2012. Published 20 April 2012.


Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 347-352 ◽  
Author(s):  
Glenn R. Wehtje ◽  
John W. Wilcut ◽  
John A. Mcguire

Mixtures of chlorimuron and 2,4-DB were additive with respect to crop injury and were either additive or slightly antagonistic with respect to weed control in greenhouse experiments. Absorption and translocation of14C following application of14C-chlorimuron and14C-2,4-DB were not affected by the presence of the other unlabeled herbicide, except in Florida beggarweed and peanut where 2,4-DB affected distribution of14C-chlorimuron in the treated leaf. In field studies, maximum efficacy was obtained with mixtures of chlorimuron plus 2,4-DB applied 7 or 9 wk after planting. Florida beggarweed control was greatest with chlorimuron or chlorimuron mixtures while the addition of 2,4-DB to chlorimuron improved morningglory and sicklepod control. At 9 and 11 wk after planting, addition of 2,4-DB to chlorimuron controlled Florida beggarweed better than chlorimuron alone. Peanut yields were increased by the addition of 2,4-DB at later applications.


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