Peanut Response to Ethalfluralin, Pendimethalin, and Trifluralin Preplant Incorporated1

2003 ◽  
Vol 30 (1) ◽  
pp. 34-37 ◽  
Author(s):  
P. A. Dotray ◽  
J. W. Keeling ◽  
W. J. Grichar ◽  
E. P. Prostko ◽  
R. G. Lemon ◽  
...  
Keyword(s):  
Field Experiments ◽  
South Texas ◽  
Stand Establishment ◽  
West Texas ◽  
Central Texas ◽  
Incorporation Method ◽  
Dinitroaniline Herbicides

Abstract Field experiments were conducted at Yoakum (south Texas) in 1996 and 1997, Comanche (central Texas) in 1998, and Lamesa (west Texas) in 1998 and 1999 to evaluate peanut tolerance to dinitroaniline herbicides. At Lamesa, ethalfluralin at 0.63 or 0.84 kg/ha, pendimethalin at 0.56 or 0.84 kg/ha, and trifluralin at 0.56 or 0.71 kg/ha were applied preplant incorporated (PPI), and at Yoakum and Comanche, ethalfluralin and pendimethalin were applied PPI at 0.67, 0.84, 1.12, and 1.68 kg/ha. There were no differences in stand establishment or yield for any treatment at Lamesa, Comanche, or Yoakum. Similarly, canopy stature was not affected at Lamesa nor was grade affected at Comanche or Yoakum. At Lamesa, yields by herbicide averaged across rates, incorporation methods, and years ranged from 4530 to 4920 kg/ha; by rate averaged across herbicides, incorporation methods, and years was 4600 to 4750 kg/ha; and by incorporation method averaged across herbicides, rates, and years was 4580 to 4770 kg/ha. At Yoakum and Comanche, yields by herbicide were 2640 and 2950 kg/ha, respectively, when averaged across rates; and by rate they ranged from 2630 to 2990 kg/ha when averaged across herbicides. These data indicate peanut has tolerance (safety) to ethalfluralin, pendimethalin, and trifluralin applied PPI in Texas.

Drip Irrigation and Stand Establishment Affect Yield and Quality of Cantaloupe

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 545d-545
Author(s):  
D.I. Leskovar ◽  
J.C. Ward ◽  
R.W. Sprague ◽  
A. Meiri
Keyword(s):  
Field Experiments ◽  
Irrigation System ◽  
Fruit Size ◽  
Growth Yield ◽  
Vegetable Production ◽  
Silty Clay ◽  
Dry Land ◽  
Stand Establishment ◽  
Yield And Quality

Water pumping restrictions of high-quality irrigation water from underground aquifers is affecting vegetable production in Southwest Texas. There is a need to develop efficient deficit-irrigation strategies to minimize irrigation inputs and maintain crop profitability. Our objective was to determine how growth, yield, and quality of cantaloupe (Cucumis melo L. cv. `Caravelle') are affected by irrigation systems with varying input levels, including drip depth position and polyethylene mulch. Stand establishment systems used were containerized transplants and direct seeding. Field experiments were conducted on a Uvalde silty clay loam soil. Marketable yields increased in the order of pre-irrigation followed by: dry-land conditions, furrow/no-mulch, furrow/mulch, drip-surface (0 cm depth)/mulch, drip-subsurface (10-cm depth)/mulch, and drip-subsurface (30 cm depth)/mulch. Pooled across all drip depth treatments, plants on drip had higher water use efficiency than plants on furrow/no-mulch or furrow/mulch systems. Transplants with drip-surface produced 75% higher total and fruit size No. 9 yields than drip-subsurface (10- or 30-cm depth) during the first harvest, but total yields were unaffected by drip tape position. About similar trends were measured in a subsequent study except for a significant irrigation system (stand establishment interaction for yield. Total yields were highest for transplants on drip-subsurface (10-cm depth) and direct seeded plants on drip-subsurface (10 and 30 cm depth) with mulch.

Direct-Seeding Techniques for Guayule Stand Establishment in West Texas

jpa ◽  
1992 ◽  
Vol 5 (1) ◽  
pp. 163-167 ◽  
Author(s):  
M. A. Foster ◽  
J. Moore
Keyword(s):  
Direct Seeding ◽  
Stand Establishment ◽  
West Texas

Evidence for rapid phenotypic and behavioural shifts in a recently established cavefish population

2019 ◽  
Author(s):  
Suzanne E McGaugh ◽  
Sam Weaver ◽  
Erin N Gilbertson ◽  
Brianna Garrett ◽  
Melissa L Rudeen ◽  
...  
Keyword(s):  
Extreme Environments ◽  
Time Frame ◽  
South Texas ◽  
Astyanax Mexicanus ◽  
North East ◽  
Surface Population ◽  
Cave Population ◽  
Cave Environment ◽  
Central Texas ◽  
Recent Origin

Abstract Cave colonization offers a natural laboratory to study an extreme environmental shift, and diverse cave species from around the world often have converged on robust morphological, physiological and behavioural traits. The Mexican tetra (Astyanax mexicanus) has repeatedly colonized caves in the Sierra de El Abra and Sierra de Guatemala regions of north-east Mexico ~0.20–1 Mya, indicating an ability to adapt to the cave environment. The time frame for the evolution of these traits in any cave animal, however, is poorly understood. Astyanax mexicanus from the Río Grande in South Texas were brought to Central Texas beginning in the early 1900s and colonized underground environments. Here, we investigate whether phenotypic and behavioural differences have occurred rapidly between a surface population and a geographically proximate cave population, probably of recent origin. Fish from the cave and surface populations differ significantly in morphological traits, including coloration, lateral line expansion and dorsal fin placement. Striking behavioural shifts in aggression, feeding and wall-following have also occurred. Together, our results suggest that morphological and behavioural changes accompanying cave colonization can be established rapidly, and this system offers an exciting and unique opportunity for isolating the genetic and environmental contributions to colonization of extreme environments.

Synthetic seismograms for a long spread of seismometer stations

Geophysics ◽  
1994 ◽  
Vol 59 (3) ◽  
pp. 450-463
Author(s):  
J. H. Rosenbaum
Keyword(s):  
Dynamic Range ◽  
Transverse Isotropy ◽  
Transversely Isotropic ◽  
Computational Effort ◽  
South Texas ◽  
P Wave ◽  
Complex Frequency ◽  
West Texas ◽  
Symmetry Properties ◽  
Elastic Layers

The assumption that the earth is made up of planeparallel, homogeneous, elastic layers, which can exhibit transverse isotropy and moderate constant‐Q attenuation, leads to an effective method of modeling the response from a point source into a long spread of seismometer stations. Most of the computations are carried out in the complex frequency and complex horizontal wavenumber domains. Minimum sampling criteria are based on an algorithm that suppresses time and distance aliasing at the expense of the large dynamic range available on the digital computer. Other artifacts can be identified and are removed by additional wavenumber filtering. Computational effort is almost independent of the number of detectors and their nature. The structure and symmetry properties of the propagator matrices describing the response are the same for isotropic and transversely isotropic layers. Synthetic seismic panels for a regional model of a west Texas well site exhibit strong, shot‐generated surface waves. A very simple model, based on a south Texas well site, shows the effects of transverse isotropy and the reverberatory nature of converted signals generated by a surface P‐wave.

Resolution of slowness and reflectors in crosswell tomography with transmission and reflection traveltimes

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE321-VE335 ◽  
Author(s):  
Kenneth P. Bube ◽  
Robert T. Langan
Keyword(s):  
Field Experiments ◽  
Oil Field ◽  
Data Sets ◽  
Traveltime Tomography ◽  
Velocity Models ◽  
West Texas ◽  
Well Spacing ◽  
High Level ◽  
Transmission And Reflection

We sometimes encounter situations in seismic imaging in which knowing the position of key reflectors between wells would be very useful. In many crosswell data sets, both transmission and reflection traveltimes for selected reflectors can be picked. We investigated the possibility that transmission-plus-reflection crosswell traveltime tomography can determine the position of these reflectors with a high level of accuracy, thereby providing an independent way of verifying (and perhaps improving) the position of these reflectors obtained from crosswell reflection imaging. We studied the effect of combining reflection traveltimes for selected reflectors with transmission traveltimes on the resolution of the interwell slowness field and depth determination of selected reflectors. We found that theoretically, the position of reflectors is determined uniquely from transmission and reflection traveltimes in a linearized continuum formulation ofcrosswell tomography. We also computed diagonal elements of the resolu-tion matrix for two crosswell geometries based on field experiments conducted in a west Texas oil field to see what effect noise has on the accuracy of our determination of reflector depths. These computational results indicate that reflector positions are indeed very well determined for these geometries, with expected errors of [Formula: see text] of the well spacing when noise in traveltimes is [Formula: see text]. Because reflector-position parameters are so well determined, including reflection traveltimes does not degrade the resolution of the slowness field as a result of introducing additional reflector-depth parameters. Actually, the resolution of the slowness field, particularly near reflectors, improves by including reflection traveltimes, in spite of the fact that we must solve for these additional depth parameters. The improvement in slowness resolution should provide velocity models that can yield more accurate reflection images.

DINITROANILINE HERBICIDES FOR GRASSY WEED CONTROL IN RAPESEED

1976 ◽  
Vol 56 (3) ◽  
pp. 705-713 ◽  
Author(s):  
P. N. P. CHOW
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Brassica Campestris ◽  
Good Control ◽  
Climatic Conditions ◽  
Yield Increase ◽  
Wild Oats ◽  
Green Foxtail ◽  
Significant Yield ◽  
Dinitroaniline Herbicides

Five substituted dinitroaniline herbicides applied as preplanting soil incorporation treatments were evaluated in six field experiments in 1971, 1973, and 1974 for controlling green foxtail (Setaria viridis (L.) Beauv.) and wild oats (Avena fatua L.), and for tolerance of rapeseed (Brassica campestris L. and B. napus L.). In these experiments, A-820 (N-sec-butyl-4-tert-butyl-2,6-dinitroapiline) had the least activity, while dinitramine (N4,N4-diethyl-α,α,α,-trifluoro-3,5-dinitrotoluene-2,4-diamine) had the greatest activity, and in some tests injured germinating rapeseed, resulting in thinned stands and reduced yield. The activity of fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoro-methyl) aniline] and profluralin [N(cyclopropyl-methyl)-α,α,α-trifluro-2, 6-dinitro-N-propyl-p-toluidine] was slightly weaker than that of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine). All these herbicides gave good control of green foxtail and wild oats. In 1971, due to low populations of green foxtail, good weed control did not give rapeseed yield increases. In 1973, under normal climatic conditions, rapeseed yields were increased significantly when the application of dinitramine, fluchloralin, profluralin, and trifluralin controlled green foxtail and wild oats successfully. In 1974, under drought conditions, good weed control from four dinitroanilines and triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate] was not reflected in significant yield increases although profluralin gave a significant yield increase in one test. Disc soil incorporation (7.5–10 cm deep) of dinitramine and trifluralin gave slightly better weed control and higher, though not significant, yield increases than harrow soil incorporation (2.5–5 cm deep).

scholarly journals Densities, plant sizes, and spatial distributions of six wild populations of Lophophora williamsii (Cactaceae) in Texas, U.S.A.

2021 ◽  
Vol 15 (1) ◽  
pp. 149-160
Author(s):  
Anna Ermakova ◽  
Carolyn V. Whiting ◽  
Keeper Trout ◽  
Colin Clubbe ◽  
Martin K. Terry ◽  
...  
Keyword(s):  
Regional Differences ◽  
Spatial Scales ◽  
Conservation Status ◽  
Regional Scale ◽  
Plant Size ◽  
South Texas ◽  
Wild Populations ◽  
Initial Information ◽  
West Texas ◽  
Plant Densities

Lophophora williamsii (Cactaceae) is thought to be threatened by habitat loss and overharvesting. However, basic demographic and habitat information to evaluate its conservation status have been lacking. We surveyed six wild populations of this species, three in South Texas and three in West Texas, to begin to address this gap. We found high levels of heterogeneity in plant presence and density at multiple spatial scales. While plant densities were not consistently different between South and West Texas, plants were significantly larger in West Texas. The two regions differ strongly in precipitation, temperature, elevation, and topography, all of which are correlated at the regional scale. Therefore, it was not possible to identify which of these variables, or other factors such as competition and human harvesting, may be responsible for the regional differences in plant size. However, our results provide initial information for determining the conservation status of this species.

scholarly journals Comparative Canopy Damage among Provenances of Baldcypress Associated with the Presence of Cercosporidium sequoiae (Ellis and Everth.) W.A. Baker and Partridge

HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1703-1705 ◽  
Author(s):  
Garry Vernon McDonald ◽  
Geoffrey C. Denny ◽  
Michael A. Arnold ◽  
Donita L. Bryan ◽  
Larry Barnes
Keyword(s):  
Selection Criteria ◽  
Taxodium Distichum ◽  
Leaf Blight ◽  
South Texas ◽  
East Texas ◽  
Rainfall Events ◽  
Geographical Regions ◽  
Central Texas ◽  
Selection Of ◽  
Canopy Damage

Seeds of Taxodium distichum (L.) Rich. were collected, germinated, and grown from native stands ranging from Mexico, Texas, Louisiana, Mississippi, and Alabama. Twenty-two provenance selections were planted in Summer 2004 in College Station, TX, in 36 replicated single-plant replications per block for a total of 792 trees. Below-average midsummer temperatures and above-average number of rainfall events were conducive to the development of a leaf blight associated with the presence of Cercosporidium sequoiae (Ellis and Everh.) W.A. Baker and Partridge. A survey conducted in Oct. 2007 rated differential defoliation responses among provenances. Selections of Taxodium distichum var. mexicanum (Gordon) from Mexico and south Texas showed defoliation rates from 89% to 96%, whereas T. distichum var. distichum from central Texas had defoliation ratings from 79% to 99%. With the exception of one family collected from the Sabinal River in Texas, the central Texas selections had similar defoliation compared with those from south Texas. Selections of T. distichum var. distichum and one selection of T. distichum var. imbricarium (Nutt.) Croom from southeastern regions (Alabama, Louisiana, Mississippi, and east Texas) showed greater tolerance to the presence of the leaf blight with 52% to 80% mean defoliation. A few individuals within these families exhibited little or no symptoms of the leaf blight. In general, those selections from high-rainfall, high-humidity areas had less defoliation associated with the presence of the leaf blight fungus, although defoliation was variable among provenances within all geographical regions. These results suggest that tolerance to defoliation from C. sequoiae could be included in selection criteria when choosing possible germplasm releases from Taxodium distichum.

Control of White Campion (Silene alba) in Birdsfoot Trefoil (Lotus corniculatus) with Dinitroaniline Herbicides

1987 ◽  
Vol 1 (1) ◽  
pp. 34-36 ◽  
Author(s):  
Donald L. Wyse ◽  
Robert L. Mcgraw
Keyword(s):  
Field Experiments ◽  
Lotus Corniculatus ◽  
Birdsfoot Trefoil ◽  
White Campion ◽  
Silene Alba ◽  
Dinitroaniline Herbicides

In 2 yr of field experiments, trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine], profluralin [N-(cyclopropylmethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)benzenamine], fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)benzenamine], ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)benzenamine], and benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine] controlled white campion [Silene alba (Mill.) E.H.L. Krause.# MELAL] during the establishment of birdsfoot trefoil (Lotus corniculatus L. ‘Leo’).

Harvesting Thermoelectric Energy from Asphalt Pavements

2017 ◽  
Vol 2628 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Utpal Datta ◽  
Samer Dessouky ◽  
A. T. Papagiannakis
Keyword(s):  
Surface Temperature ◽  
Field Experiments ◽  
Asphalt Pavement ◽  
Electrical Power ◽  
Weather Conditions ◽  
Research Field ◽  
South Texas ◽  
Element Analysis ◽  
Pavement Surface ◽  
Thermoelectric Energy

The goal of this study was to develop a prototype for harvesting thermoelectric energy from asphalt pavement roadways. This emerging research field encompasses technologies that capture the existing thermal energy in pavements to generate electricity without depleting natural resources. In lower latitudes, such as south Texas, the asphalt pavement surface temperature in the summer can reach 55°C because of solar radiation. Soil temperatures below the pavement, however, are roughly constant (i.e., 27°C to 33°C) at relatively shallow depths (150 mm). This thermal gradient between the surface temperature and the pavement substrata can be used to generate electrical power through thermoelectric generators (TEGs). The proposed prototype collects heat energy from the pavement surface and transfers the energy to a TEG embedded in the subgrade at the edge of the pavement shoulder. Evaluation of this prototype was carried out through finite element analysis, laboratory testing, and field experiments. The results suggest that the 64- × 64-mm TEG prototype can generate an average of 10 mW of electric power continuously over a period of 8 h in the weather conditions in south Texas. Scaling up this prototype by using multiple TEG units could generate sufficient electricity to sustainably power low-watt LED lights and roadway and traffic sensors in off-grid, remote areas.

Sign in / Sign up

Export Citation Format

Share Document