scholarly journals Phenyl Isothiocyanate Performance on Purple Nutsedge under Virtually Impermeable Film Mulch

2010 ◽  
Vol 20 (2) ◽  
pp. 402-408 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur ◽  
John D. Mattice

Purple nutsedge (Cyperus rotundus) is a troublesome weed in vegetable crops in the southern United States. Methyl bromide is widely used for effective purple nutsedge control in polyethylene-mulched vegetable crops. With the impending ban on methyl bromide in the United States, an effective alternative is needed. Laboratory and greenhouse experiments were conducted to determine the effect of phenyl isothiocyanate (ITC) concentration and exposure period on purple nutsedge tuber viability and to compare the retention of phenyl ITC in soil under low-density polyethylene (LDPE) and virtually impermeable film (VIF) mulches. Additionally, field experiments were conducted to evaluate the effectiveness of phenyl ITC under VIF mulch against purple nutsedge. A phenyl ITC concentration of 676 ppm in soil for 3 days in a sealed environment reduced purple nutsedge tuber viability by 97% compared with a nontreated control. Phenyl ITC retention was higher in soil covered with VIF mulch than with LDPE mulch. The predicted half-life of phenyl ITC under LDPE and VIF mulch was 6.1 and 8.9 days, respectively. In field experiments, phenyl ITC at 1500 kg·ha−1 under VIF mulch suppressed purple nutsedge shoots and reduced viable tuber density ≥72%, but control was not as effective as methyl bromide at 390 kg·ha−1 (67% methyl bromide:33% chloropicrin). Therefore, phenyl ITC up to 1500 kg·ha−1 under a VIF mulch is not a viable alternative to methyl bromide for effective purple nutsedge control.

1987 ◽  
Vol 1 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Gene D. Wills

Both purple nutsedge (Cyperus rotundusL. # CYPRO) and yellow nutsedge (C. esculentusL. # CYPES) are problem weeds in crops in many parts of the world. Yellow nutsedge is found in all U.S. states. Purple nutsedge is confined to the southern region of the United States, ranging from North Carolina across southern Arkansas and into southern California.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 198
Author(s):  
Yinping Li ◽  
George N. Mbata ◽  
Somashekhar Punnuri ◽  
Alvin M. Simmons ◽  
David I. Shapiro-Ilan

Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is among the most economically important insect pests of various vegetable crops in the Southern United States. This insect is considered a complex of at least 40 morphologically indistinguishable cryptic species. Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) was initially introduced in the United States around 1985 and has since rapidly spread across the Southern United States to Texas, Arizona, and California, where extreme field outbreaks have occurred on vegetable and other crops. This pest creates extensive plant damage through direct feeding on vegetables, secreting honeydew, causing plant physiological disorders, and vectoring plant viruses. The direct and indirect plant damage in vegetable crops has resulted in enormous economic losses in the Southern United States, especially in Florida, Georgia, and Texas. Effective management of B. tabaci on vegetables relies mainly on the utilization of chemical insecticides, particularly neonicotinoids. However, B. tabaci has developed considerable resistance to most insecticides. Therefore, alternative integrated pest management (IPM) strategies are required, such as cultural control by manipulation of production practices, resistant vegetable varieties, and biological control using a suite of natural enemies for the management of the pest.


1987 ◽  
Vol 1 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Leo E. Bendixen ◽  
U. B. Nandihalli

The family Cyperaceae includes approximately 3000 species, of which about 220 species are identified as weeds (Table 1). Nearly 42% of these weeds are in the genusCyperus. An additional 43% are in three other genera,Eleocharis,Scirpus, andFimbristylis. The remaining 15% are found in six other genera,Scleria,Kyllinga,Rhynchospora,Bulbostylis,Fuira, andDichromena. Purple nutsedge (Cyperus rotundusL. # CYPRO) was identified as the world's worst weed based on the number of countries where it was reported as a serious, principal, or common weed. Competition with crops was the major factor in determining weediness. From the same report, yellow nutsedge (Cyperus esculentusL. # CYPES) ranked sixteenth. This contrasts with relative rankings of these two species in the United States where yellow nutsedge is more widespread than purple nutsedge.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 525b-525 ◽  
Author(s):  
S.J. Locascio ◽  
D.W. Dickson

In past work, dichloropropene + 17% Pic (1,3-D + Pic) at 327 L·ha–1 plus pebulate provided good control of nematode, soil fungi, and nutsedge in mulched tomato (Lycopersicon esculentum Mill.) and is considered the best alternative for methyl bromide (MBr) + chloropicrin (Pic), which is scheduled for phase-out in the United States by Jan. 2001. Metam-sodium did not provide acceptable pest control. In the present study, metam-Na (295 L·ha–1 combined with Pic (168 kg·ha–1) + 4.5 kg·ha–1 pebulate, and 1,3-D + 35% Pic at 168 and 225 L·ha–1 + pebulate were compared to MBr-Pic (98-2% at 345 kg·ha–1 and 67-33% at 505 kg·ha–1). Fumigants were injected into the bed except metam-Na and pebulate were surface-applied and incorporated and drip tubing and mulch were applied. Marketable yields with MBr-Pic, 225 L·ha–1 1,3-D + Pic, and metam-Na + Pic were higher than with the check. Yields with metam-Na alone or with additional water before transplanting were similar to the check. Nutsedge was controlled with MBr-Pic and all treatments with pebulate. Nematode root-gall ratings were high on tomato grown without fumigants (8.9 rating on a scale of 0 to 10 with 0 = no galling), low with MBr-Pic (0.33), and intermediate with all other treatments (2.2 to 5.5) except with 168 L·ha–1 1-3-D + Pic (8.3). This study indicates that metam-Na + Pic + pebulate also is a possible alternative to MBr-Pic for tomato.


2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.


Modern Italy ◽  
2021 ◽  
pp. 1-17
Author(s):  
Gilberto Mazzoli

During the Age of Mass Migration more than four million Italians reached the United States. The experience of Italians in US cities has been widely explored: however, the study of how migrants adjusted in relation to nature and food production is a relatively recent concern. Due to a mixture of racism and fear of political radicalism, Italians were deemed to be undesirable immigrants in East Coast cities and American authorities had long perceived Italian immigrants as unclean, unhealthy and carriers of diseases. As a flipside to this narrative, Italians were also believed to possess a ‘natural’ talent for agriculture, which encouraged Italian diplomats and politicians to propose the establishment of agricultural colonies in the southern United States. In rural areas Italians could profit from their agricultural skills and finally turn into ‘desirable immigrants’. The aim of this paper is to explore this ‘emigrant colonialism’ through the lens of environmental history, comparing the Italian and US diplomatic and public discourses on the potential and limits of Italians’ agricultural skills.


Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 263-268 ◽  
Author(s):  
S. K. Gremillion ◽  
A. K. Culbreath ◽  
D. W. Gorbet ◽  
B. G. Mullinix ◽  
R. N. Pittman ◽  
...  

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.


Ecclesiology ◽  
2011 ◽  
Vol 7 (2) ◽  
pp. 195-219
Author(s):  
Paul Fiddes

AbstractThe main substance of this article is an extended review of a recent book by a Southern Baptist historical theologian, Malcolm Yarnell, entitled The Formation of Christian Doctrine, which aims to root the development of doctrine in a free-church ecclesiology. This review offers the opportunity to examine a spectrum of ecclesiologies that has recently emerged among Baptists in the Southern region of the United States of America. Four 'conservative' versions of ecclesiology are identified, which are named as 'Landmarkist', 'Reformed', 'Reformed-Ecumenical' and 'Conservative Localist'. Four 'moderate' versions are similarly identified, and named as 'Voluntarist', 'Catholic', 'Moderate Localist' and 'World-Baptist'. While these categories are not intended to be mutually exclusive, the typology is useful both in positioning Yarnell's particular thesis, and in making comparisons with recent Baptist ecclesiology in Great Britain, which has focussed on the concept of covenant. Yarnell's own appeal to covenant is unusual in Southern Baptist thinking, and means that he cannot be easily fitted into the typology suggested. Though he belongs most evidently to the group named here as 'Conservative Localists', and is overtly opposed to any concept of a visible, universal church except in an eschatological sense, it is suggested that his own arguments might be seen as tending towards a more 'universal' view of the reality of the church beyond its local manifestation. His own work thus offers the promise that present polarizations among Baptists in the southern United States might, in time, be overcome.


Weed Science ◽  
2004 ◽  
Vol 52 (2) ◽  
pp. 185-200 ◽  
Author(s):  
Theodore M. Webster ◽  
John Cardina

Florida beggarweed is native to the Western Hemisphere but is naturalized around the world. During the last century, the mechanization of agriculture has transitioned Florida beggarweed from an important forage component to a weed of significance in the coastal plain of the southeast United States. This herbaceous annual is naturalized and found in fields and disturbed areas throughout the southern United States. The characteristics that made Florida beggarweed a good forage crop also make it a formidable weed. This review describes the importance of Florida beggarweed as a weed in the southern United States and the taxonomy of this species and details the distribution throughout the world and within the United States. The ecology of Florida beggarweed and its interactions with crop plants, insects, nematodes, and plant pathogens also are summarized. Finally, management of Florida beggarweed in agricultural systems using cultural practices and herbicides is reviewed.


2002 ◽  
Vol 13 (1) ◽  
pp. 14-15
Author(s):  
Sally M. Schneider ◽  
Kenneth W. Vick

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