Sorption and Mobility of Chlorimuron in Alabama Soils

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 428-433 ◽  
Author(s):  
Andrew J. Goetz ◽  
Robert H. Walker ◽  
Glenn Wehtje ◽  
Ben F. Hajek

Soil thin-layer chromatography and a soil solution technique were used to evaluate chlorimuron adsorption and mobility in five Alabama soils. The order of adsorption was atrazine > metribuzin > chlorimuron; mobility was chlorimuron > metribuzin > atrazine. The order of adsorption of chlorimuron in the five soils was Sumter clay > Eutaw clay > Lucedale fine sandy loam > Decatur silt loam > Dothan sandy loam, and Rfvalues were 0.63, 0.73, 0.69, 0.76, and 0.80, respectively. Chlorimuron mobility and adsorption were not highly correlated to any one soil type. Adsorption of all herbicides was inversely related to soil pH. Maximum chlorimuron adsorption in the Hiwassee loam was attributed to the high hematite and gibbsite content of the soil.

Weed Science ◽  
1977 ◽  
Vol 25 (6) ◽  
pp. 515-520 ◽  
Author(s):  
A.E. Hiltbold ◽  
G.A. Buchanan

Persistence of 1.12, 2.24, and 3.36 kg/ha of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] applied preemergence to corn (Zea maysL. ‘Funk's 4761′) was determined in three soils, each providing a range of pH from 5 to 7. Samples of surface soil from each plot were collected at intervals after atrazine application until there was no evidence of phytotoxicity to oat (Avena sativaL. ‘Florida 501′) in bioassay. Persistence (Y50) was defined as the number of days following atrazine application until bioassay indicated 50% relative growth of oats (no atrazine = 100% growth). This period ranged from 24 to 178 days, depending upon soil type, pH, and atrazine rate. Persistence of atrazine increased with increasing soil pH. The effect of soil pH was essentially the same at each atrazine rate and did not vary appreciably with years in a given soil. In McLaurin sandy loam, atrazine persisted 8 to 9 days longer with each unit increase in soil pH. In Hartsells fine sandy loam and Decatur silt loam, atrazine persistence increased 9 to 13 days and 29 days, respectively, with each unit pH.


Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 98-101 ◽  
Author(s):  
F. W. Roeth ◽  
T. L. Lavy

Root and shoot extracts of 3-week-old sudangrass [Sorghum sudanense(Piper) Stapf, var. Piper], grain sorghum [Sorghum bicolor(L.) Moench], and corn (Zea maysL.) plants degraded 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) in order: shoot > root and corn ≫ sorghum = sudangrass. In 3-week-old detopped plants, the rate of atrazine exudation was 14 times greater in sudangrass and sorghum than in corn when grown in Keith sandy loam containing 0.5 ppmw14C-atrazine. Extraction and analysis of plant shoots revealed that 7 to 8% of the14C was present as atrazine in sudangrass and sorghum whereas no atrazine was found in corn. In14C tracer studies, thin-layer chromatography showed that sudangrass and sorghum metabolized atrazine by a pathway which differed from the pathway in corn. Sudangrass and sorghum metabolized atrazine primarily to 2-chloro-4-amino-6-(isopropylamino)-s-triazine and 2-chloro-4-amino-6-(ethylamino)-s-triazine which are only partially detoxified compounds. Corn metabolized atrazine to 2-hydroxy-4-(ethylamino)-6-(isopropylamino)-s-triazine (hydroxyatrazine) which is non-phytotoxic.


1998 ◽  
Vol 8 (1) ◽  
pp. 74-77
Author(s):  
Regina P. Bracy ◽  
Richard L. Parish

Stands of brassica crops obtained with precision seeders are sometimes inadequate or nonuniform. Although several types of covering devices and presswheels are available from precision seeder manufacturers, the effects of covering devices and presswheels on plant emergence of direct-seeded Brassica crops have not been determined. In Spring and Fall 1996, six crops of mustard [Brassica juncea (L.) Czerniak] and four crops of cabbage (Brassica oleracea L. capitata group) were direct seeded with a precision belt seeder using four covering devices and four rear presswheels. All of the covering devices and presswheels evaluated were adequate for direct seeding mustard and cabbage under the soil moisture conditions and soil type (silt loam or fine sandy loam) found in these experiments. Although poor stands were obtained with all seed covering devices and presswheels when 7.8 inches (199 mm) of rain occurred within 3 days of planting, plant stand of cabbage was greater when the paired arm device was used than with drag-type or no covering devices.


Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 166-170 ◽  
Author(s):  
Timothy L. Grey ◽  
Glenn R. Wehtje ◽  
Ben F. Hajek ◽  
Robert H. Walker

Sorption and mobility of14C-bentazon were evaluated using soil solution and soil-thin-layer chromatography, respectively on three Coastal Plain soils. The proportion of bentazon adsorbed, was pH and concentration dependent and ranged between 28 to 47, 31 to 61, and 17 to 68% for the Dothan loamy sand, Greenville clay, and Troup loamy sand, respectively. Bentazon sorption decreased as soil pH increased from 5.4 to 5.8 on the Troup loamy sand, regardless of bentazon concentration. Sorption of 1 and 10 ppm bentazon decreased as soil pH increased from 5.0 to 5.7 on the Greenville clay and 6.1 to 6.4 on the Dothan loamy sand. Bentazon was least mobile on the Greenville clay and mobility increased as pH increased. Mobility of bentazon was greatest on the Troup loamy sand and was not pH dependent. Bentazon mobility decreased as soil pH increased for the Dothan loamy sand.


Author(s):  
H. R. Bolliger ◽  
M. Brenner ◽  
H. Gänshirt ◽  
Helmut K. Mangold ◽  
H. Seiler ◽  
...  

1969 ◽  
Vol 61 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Leon J. Sholiton ◽  
Emile E. Werk

ABSTRACT Rat and bovine brain have been incubated with testosterone-4-14C under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less-polar, iso-polar, and more polar fractions. The components of the less-polar fraction were separated by acetylation and thin-layer chromatography and the major end-products identified by recrystallization to constant specific activity or constant 3H/14C ratios. Androst-4-enedione and 5α-dihydrotestosterone were formed consistently under the conditions utilized. Trace amounts of other less-polar metabolites were noted occasionally.


Sign in / Sign up

Export Citation Format

Share Document