Effect of Shade on Texasweed (Caperonia palustris) Emergence, Growth, and Reproduction

Weed Science ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 593-599 ◽  
Author(s):  
Rakesh K. Godara ◽  
Billy J. Williams ◽  
James P. Geaghan
Keyword(s):  
Fruit Production ◽  
Leaf Biomass ◽  
Research Station ◽  
State University ◽  
Potted Plants ◽  
Louisiana State University ◽  
Polypropylene Fabric ◽  
Height Increase ◽  
Growth Differences ◽  
Light Capture

Experiments were conducted on potted plants under field conditions in 2007 and 2008 at the Louisiana State University Agricultural Center's Northeast Research Station near St. Joseph, LA, to evaluate Texasweed response to shade. Shade levels of 30, 50, 70, and 90% were achieved using 1.8-m by 1.8-m by 1.8-m tents built using 2.54-cm-diam polyvinyl chloride (PVC) pipe and polypropylene fabric. Shade had no effect on Texasweed emergence but significantly reduced its growth. There were significant growth differences between plants transferred directly and gradually to a given shade level. At 100 d after emergence, plants gradually exposed to 30, 50, 70, and 90% shade had 13, 22, 37, and 58% less total dry matter per plants, respectively, than did those in 0% shade. Texasweed height in 70 and 90% shade was increased by 28 and 20%, respectively. Texasweed seemed to mitigate the adverse effect of shade by increasing specific leaf area (SLA) and percentage of leaf biomass. Increasing SLA and the percentage of leaf biomass appears to be a strategy for efficient allocation of biomass for light capture and carbohydrate synthesis, which can be used for height increase until the plant rises above the crop canopy. Although fruit production was significantly reduced, Texasweed was able to reproduce in 90% shade.

Evaluation of Imazosulfuron for Broadleaf Weed Control in Drill-Seeded Rice

2012 ◽  
Vol 26 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Rakesh K. Godara ◽  
Billy J. Williams ◽  
Eric P. Webster ◽  
James L. Griffin ◽  
Donnie K. Miller
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Residual Activity ◽  
Research Station ◽  
State University ◽  
Louisiana State University ◽  
Hemp Sesbania

Field experiments were conducted in 2006, 2007, and 2008 at the Louisiana State University Agricultural Center's Northeast Research Station near St. Joseph, LA, to evaluate imazosulfuron programs involving rate, application timings, and tank mixes for PRE and POST broadleaf weed control in drill-seeded rice. Imazosulfuron showed residual activity against both Texasweed and hemp sesbania. PRE-applied imazosulfuron at 168 g ai ha−1and higher rates provided 83 to 93% Texasweed control at 4 WAP. At 12 WAP, Texasweed control with 168 g ha−1and higher rates was 92%. Hemp sesbania control with 168 g ha−1and higher rates was 86 to 89% at 4 WAP and 65 to 86% at 12 WAP. Imazosulfuron at 224 g ha−1applied EPOST provided 84 to 93% Texasweed control and 82 to 87% hemp sesbania control, and it was as effective as its tank mixture with bispyribac-sodium. When applied LPOST, four- to five-leaf Texasweed, imazosulfuron alone at 224 g ha−1was not effective against Texasweed and hemp sesbania, but did improve weed control when mixed with bispyribac-sodium at 17.6 g ai ha−1.

Overlay of residual herbicides in rice for improved weed management

2019 ◽  
Vol 33 (03) ◽  
pp. 426-430 ◽  
Author(s):  
Matthew J. Osterholt ◽  
Eric P. Webster ◽  
David C. Blouin ◽  
Benjamin M. McKnight
Keyword(s):  
Weed Management ◽  
Research Station ◽  
State University ◽  
Yellow Nutsedge ◽  
Louisiana State University

AbstractA study was conducted at the Louisiana State University Agricultural Center’s H. Rouse Caffey Rice Research Station in 2017 and 2018 to evaluate a prepackaged mixture of clomazone plus pendimethalin applied delayed preemergence (DPRE) or POST within an herbicide residual overlay with saflufenacil, clomazone, or quinclorac. POST applications included penoxsulam or halosulfuron in combination with the second residual application. No differences were observed in barnyardgrass control (92% to 98%) at 14 days after treatment (DAT). At 42 DAT, barnyardgrass treated with clomazone plus pendimethalin in combination with either clomazone or quinclorac at either timing was controlled 95% to 96%. However, when saflufenacil was applied PRE, regardless of the POST herbicide or when saflufenacil was applied POST with halosulfuron, barnyardgrass control was reduced to 78% to 81%, compared with 95% to 96% with the control with all other residual combinations. Yellow nutsedge and rice flatsedge control increased when treated with halosulfuron compared with penoxsulam across all evaluation dates. At 28 and 42 DAT, texasweed treated with saflufenacil PRE, regardless of POST applications, was controlled 83% and 87%, respectively, and this was greater control than provided by clomazone or quinclorac applied PRE regardless of POST herbicide program.

scholarly journals Performance of Sweetpotato Foundation Seed after Incorporation into Commercial Operations in Louisiana

2010 ◽  
Vol 20 (6) ◽  
pp. 977-982 ◽  
Author(s):  
Christopher A. Clark ◽  
Tara P. Smith ◽  
Donald M. Ferrin ◽  
Arthur Q. Villordon
Keyword(s):  
Seed Production ◽  
Ipomoea Batatas ◽  
Seed Quality ◽  
The United States ◽  
Research Station ◽  
State University ◽  
Incidence Data ◽  
Louisiana State University ◽  
Virus Incidence ◽  
Foundation Seed

Because sweetpotato (Ipomoea batatas) is vegetatively propagated, viruses and mutations can accumulate readily, which can lead to cultivar decline. Sweetpotato foundation seed programs in the United States maintain the integrity of commercial seed stock by providing virus-tested (VT) foundation seed to commercial producers. A survey was conducted in Louisiana from 2007 to 2009 to examine the performance and quality of the foundation seed after it had been integrated into commercial sweetpotato operations. G1 seed [grown 1 year after virus therapy in the foundation seed production field at the Sweet Potato Research Station, Louisiana State University Agricultural Center (LSU AgCenter), at Chase, LA] was used as a reference to compare the yield and virus incidence of growers' generation 2 (G2) and generation 3 (G3) seed roots (grown in the growers' seed production fields 1 or 2 years following the year of foundation seed production). Although yields of plants grown from G2 and G3 seed were 86.3% and 86.1% for U.S. No. 1 and 83.3% and 86.0% for total marketable, respectively, compared with the yields from G1 seed, they were not significantly different. Yield and virus incidence data suggest that seed quality may vary from year to year and from location to location. Results from this study suggest that producers are realizing yield benefits by incorporating VT foundation seed into their production schemes, but further benefits could be attained if ways to reduce re-infection with viruses can be found.

Effect of meteorological variables on crawfish harvest in Louisiana, USA

2020 ◽  
Vol 81 ◽  
pp. 15-28
Author(s):  
VM Brown ◽  
MG Shirley ◽  
BD Keim ◽  
BD Marx ◽  
CG Lutz
Keyword(s):  
Low Temperature ◽  
Meteorological Variables ◽  
Research Station ◽  
Significant Variable ◽  
State University ◽  
Monthly Average ◽  
Louisiana State University ◽  
Selection Processes ◽  
Harvest Data ◽  
Positive Effect

This study examines the effect of meteorological variables, such as temperature, precipitation, cloud cover, and relative humidity on average monthly crawfish (Procambarus spp.) harvests at 6 research ponds located at the Aquaculture Research Station in Baton Rouge, Louisiana, USA, operated by the Louisiana State University Agricultural Center. Eight years (2006-2013) of harvest data were collected spanning February, March, and April of each year. Using multiple regression and model selection processes, the effect of meteorological variables was assessed at 3 different monthly lags (lag 0, 1, and 2) to determine which combination of variables best explained variance in average monthly crawfish pounds per trap (AMPT). The final model selected for lag 0 (adj-rsq = 0.73, p < 0.01), lag 1 (adj-rsq = 0.71, p < 0.01), and lag 2 (adj-rsq = 0.69, p < 0.01) generally included the same variables: monthly average low temperature, precipitation, and the preceding October/November precipitation (ON). Both monthly average low temperature and ON exhibited a statistically significant (p ≤ 0.05) positive effect on AMPT while controlling for other variables in the model, revealing the importance of warm temperatures and precipitation during October/November for crawfish harvests. Precipitation during the harvest month was not significant, but increased precipitation 1 and 2 mo before harvest significantly decreased AMPT. The number of hours with temperatures ≤0°C was also a significant variable negatively associated with AMPT 1 and 2 mo before harvest and, along with precipitation, could potentially be an early indicator for AMPT before harvests begin in southern Louisiana.

Interactions of Clomazone Plus Pendimethalin Mixed with Propanil in Rice

2021 ◽  
pp. 1-21
Author(s):  
Matthew J. Osterholt ◽  
Eric P. Webster ◽  
Benjamin M. McKnight ◽  
David C. Blouin
Keyword(s):  
Rice Field ◽  
Rice Yield ◽  
Research Station ◽  
State University ◽  
Yellow Nutsedge ◽  
Louisiana State University ◽  
Rough Rice ◽  
Herbicide Mixtures ◽  
Synergistic Response

A study was conducted at the Louisiana State University Agricultural Center’s H. Rouse Caffey Rice Research Station in 2017 and 2018 to evaluate the interaction between a pre-package mixture of clomazone plus pendimethalin applied at 0, 760, 1145, or 1540 g ai ha-1 mixed with propanil at 0, 1120, 2240, or 4485 g ai ha-1. A synergistic response occurred when barnyardgrass was treated with all rates of clomazone plus pendimethalin mixed with either rate of propanil evaluated at 56 d after treatment. Unlike barnyardgrass, an antagonistic response occurred for yellow nutsedge control when treated with 760 and 1540 g ha-1 of clomazone plus pendimethalin mixed with 1120 or 2240 g ha-1 of propanil at 28 d after treatment; however, 1145 g ha-1 of clomazone plus pendimethalin mixed with 4485 g ha-1 of propanil resulted in a neutral interaction. At 28 d after treatment, Rice flatsedge treated with for all herbicide mixtures resulted in neutral interactions. The synergism of clomazone plus pendimethalin applied at 1540 g ha—1 mixed with propanil applied at 2240 or 4485 g ha-1 for barnyardgrass control resulted in an increased rough rice yield compared with 760 or 1145 g ha-1 of clomazone plus pendimethalin mixed with propanil applied at 1120 or 2240 g ha-1. These results indicate if barnyardgrass and rice flatsedge are present in a rice field the pre-package mixture of clomazone plus pendimethalin mixed with propanil can be an option for growers. However, if yellow nutsedge infest the area other herbicides may be needed.

scholarly journals Greenhouse and Landscape Performance of Bedding Plants in Biocontainers

2011 ◽  
Vol 21 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Jeff S. Kuehny ◽  
Matt Taylor ◽  
Michael R. Evans
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
State University ◽  
University Of Arkansas ◽  
Bedding Plants ◽  
Louisiana State University ◽  
Landscape Performance ◽  
Production Practices ◽  
Growth Differences ◽  
Plastic Containers

Biodegradable and plastic containers were evaluated for greenhouse and landscape production of ‘Score Red’ geranium (Pelargonium ×hortorum), ‘Grape Cooler’ vinca (Catharanthus roseus), or ‘Dazzler Lilac Splash’ impatiens (Impatiens wallerana) at Louisiana State University (LSU), Baton Rouge, LA; Longwood Gardens (LWG), Kennett Square, PA; and University of Arkansas (UA), Fayetteville, AR. Of the 5-inch containers, the highest geranium and vinca shoot growth occurred in plastic containers compared with bioplastic and rice straw containers. Of the 4-inch containers, paper containers produced the greatest geranium shoot growth compared with the peat containers at LSU and LWG. Shoot growth in impatiens was similar for all container types at all three locations. When all container types were considered, there was no difference in the root growth of geranium or impatiens at all three locations. However, vinca had the highest root growth in paper containers compared with that in peat and coconut fiber. The root:shoot (R:S) ratio of geranium were mixed for all pot sizes, types, and locations. Vinca R:S ratio was highest in both the 4- and 5-inch plastic control containers at LSU and lowest in both plastic containers at LWG. Direct plant containers generally performed well in the landscape as the plants grown in plastic containers at LWG. Plants grown in all tested containers produced marketable plants for both the retail and landscape markets. However, growers and landscapers should be aware of growth differences that may occur when using biodegradable containers and align production practices accordingly.

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