Effect of Soil Type and pH on Persistence and Carryover of Imidazolinone Herbicides

1993 ◽  
Vol 7 (2) ◽  
pp. 452-458 ◽  
Author(s):  
Mark M. Loux ◽  
Kirk D. Reese

Field studies were conducted in 1988 through 1990 to determine the effect of soil pH, over a 4.5 to 6.5 range, on imazethapyr persistence and on imazaquin and imazethapyr carryover to ‘Pioneer 3377’ corn in a Crosby silt loam (1.6% organic matter) and a Hoytville clay (3.3% organic matter). Imazethapyr appeared to be more persistent in Hoytville clay than in Crosby silt loam. In Crosby silt loam, imazethapyr persistence increased as pH decreased, whereas soil pH did not affect persistence in Hoytville clay. Imazaquin or imazethapyr did not affect corn grown the year following application to Crosby silt loam. Imazethapyr applied to Hoytville clay did not cause significant injury or yield reduction to corn. Carryover of imazaquin in Hoytville clay caused corn injury and yield reduction, increased as pH decreased, and was more evident at 280 g ai ha−1than at 140 g ha−1.

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 490-496 ◽  
Author(s):  
Mark M. Loux ◽  
Kirk D. Reese

Laboratory and field studies were conducted in 1988 through 1990 to determine the effect of soil pH on imazaquin adsorption and persistence in a Crosby silt loam (1.6% organic matter) and a Hoytville clay (3.3% organic matter). Above a pH of 6, 6 to 7% of the total imazaquin present was adsorbed to both soils. Adsorption increased as pH decreased from about 7 to 4.5, with a maximum of 16.5 and 31% adsorbed on Crosby and Hoytville soils, respectively. Imazaquin was more persistent in the Hoytville clay than in the Crosby silt loam. Herbicide dissipated more slowly in both soils in 1988 than in 1989 due to dry soil conditions immediately prior to and following herbicide application in 1988. In both soils, imazaquin persistence increased as soil pH decreased, over a pH range from 6.5 to 4.5. Increased persistence with decreasing pH was attributed in part to increased adsorption and decreased availability for microbial degradation.


1996 ◽  
Vol 21 (1) ◽  
pp. 352-352
Author(s):  
Stanley R. Swier

Abstract The trial was conducted 10 May on a golf course rough, Amherst, NH. Plots were 10 X 10 ft, replicated 4 times, in a RCB design. Merit WP was applied in 4 gal water/1000 ft2 with a watering, can. Merit G granules were applied with a homemade salt shaker. Treatments were irrigated with 0.5 inch water after application. Plots were rated 30 Sep by counting the number of live grubs per 1 ft2. Conditions at the time of treatment were: air temperature 70°F; wind, 3 MPH; sky, clear; soil temperature, 1 inch, 60°F; thatch depth, 0.5 inch soil pH, 5.4; slope 0%; soil texture, silt loam, 47% sand, 50% silt, 3% clay; soil organic matter, 6.9%; soil moisture, 21.8%.


Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 378-382 ◽  
Author(s):  
J. A. Best ◽  
J. B. Weber ◽  
T. J. Monaco

Field studies indicated that liming an acid Bladen silt loam from pH 5.5 to 7.5 increased the phytotoxicity of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and prometryn [2,4-bis-(isopropylamino)-6-methyoxy-s-triazine]. Liming greatly increased the persistence of atrazine, but did not affect prometryn dissipation. Liming increased the14C-concentration present in the shoots of corn (Zea MaysL. ‘Pioneer 3369A’), cotton (Gossypium hirsutumL. ‘Coker 201’), and soybeans [Glycine Max(L.) Merr. ‘Ransom’] from soil treated with14C-ring labeled atrazine, prometryn, and hydroxyatrazine [2-hydroxy-4-(ethylamino)-6-(isopropylamino)-s-triazine] in greenhouse studies. Decreases in14C-uptake by the crops were associated with adsorption and degradation of the compounds in the soil. Atrazine was taken up in much greater amounts than hydroxyatrazine. Cotton absorbed less of thes-triazines than soybeans or corn from soil.


1997 ◽  
Vol 22 (1) ◽  
pp. 371-371
Author(s):  
Stanley R. Swier ◽  
Alan Rollins ◽  
Bryan Carney

Abstract This trial was conducted at Amherst Country Club, Amherst, NH. The lawn was mowed at 1.5 inches and irrigated daily (0.1 inch). All treatments were applied on 19 Aug to 7 X 11 ft plots with 1-ft buffers, replicated 5 times in an RCB design. Liquid formulations were applied with a 2-wheel bicycle-type CO2 boom sprayer equipped with 4 spray heads fitted with a 50-mesh strainer and an 8004 fan-type nozzle. The volume of water and insecticide mix per plot was 2 gal/1000 ft2 delivered at 40 psi. Granular formulations were evenly dispersed using large plastic salt shakers. The surface of the turf was free of moisture (dew) at time of application. The plots were irrigated post-treatment with 0.4 in of water. Grubs were primarily 2nd instar. Weather conditions at time of application were as follows. Air, temp; 78°F; sky, clear; wind, moderate breeze. Soil conditions were as follows: surface temp, 80°F; at 1-inch depth, 76°F; at 2-inch depth, 75°F; soil pH, 5.6; texture, silt loam; sand, 50%; silt, 43%; clay, 7%; dry matter, 81%; moisture, 19%; organic matter, 5%. The trial was rated on 20 Sep using a Ryan 18-inch sod cutter to cut the plots to a depth of 3/4 inch. A 3 ft2 piece of sod was moved and live grubs counted.


Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 262-266 ◽  
Author(s):  
Sharon A. Clay ◽  
William C. Koskinen

Adsorption and desorption isotherms for atrazine and two metabolites, hydroxyatrazine (HA) andS-glutathione atrazine (GSHA), were determined by batch equilibration on Plano and Waukegan silt loam soils at two soil pH levels (Plano, 6.1 and 4.5; Waukegan, 6.1 and 4.0). Freundlich adsorption isotherms were not affected by soil type except for GSHA at pH 4.0 to 4.5. When averaged over both soils, the order of adsorption at pH 6.1 was atrazine (Kf= 3.7) < GSHA (Kf= 7.3) << HA (Kf= 25) and at pH 4.0–4.5 was atrazine (Kf= 6.1) << HA (Kf= 58) ≤ GSHA (Kf: Plano = 35; Waukegan = 78). The average slope of the adsorption isotherms (1/nads) was 0.81. The slopes of all desorption isotherms (1/ndes) were less than their respective 1/nads, indicating hysteresis. Atrazine desorbed into soil solution (1/ndes> 0.0). With the exception of GSHA which desorbed from the pH 6.1 Plano silt loam (1/ndes= 0.15), desorption of HA and GSHA from other treatments was negligible (1/ndes= 0.0). Consequently, leaching of HA and GSHA in these and similar soils is not likely, due to high adsorption and low desorption.


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.


1996 ◽  
Vol 21 (1) ◽  
pp. 327-327
Author(s):  
Stanley R. Swier ◽  
Alan Rollins

Abstract Three treatments were applied to third and fourth instar BCW larvae at Amherst Country Club. Plots were 7 X 7 ft, replicated 4 times, in a RCB design. Treatments were applied 7 Sep and rated 14 Sep (7 DAT). Treatments were applied with a CO2 boom sprayer, 8004 nozzles, at 40 PSI, in 2 gal water per 10002. Plots were rated using a soap flush and counting the number of emerging larvae. Conditions at the time of treatment were: air temperature, 84.3°F; wind, calm; sky, cloudy; soil temperature, 77.3°F; thatch depth, 0.25 inch; soil pH, 5.7; slope, 0%; soil texture, silt loam: sand 40%, silt 59%, clay 1%; soil organic matter, 3.7%; soil moisture, 22.6%; post treatment precipitation, 0.1 inch daily; mowing height, 0.187 inch.


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.


1969 ◽  
Vol 20 (2) ◽  
pp. 655-679
Author(s):  
Arnaldo Vélez Franceschi

1. Organic matter, buffer capacity, and the relation of changes in reaction to the solubilities of the mineral nutrient elements in six samples of Toa silt loam were studied. 2. The buffer characteristics may vary rather widely within a given soil type. The buffer curves for different samples of Toa silt loam show that the presence of larger amounts of organic matter markedly increases the buffer capacity near neutrality . This is reflected in the flatter buffer curves. The samples which contained lower quantities of organic matter are most highly buffered at the extreme ranges of high acidity and basicity. This is indicated by typical sigmoid buffer curves. 3. The state of the decomposition of the organic matter in these samples indicates as has been shown by previous work that the buffering effect of the organic matter is associated with the lignin-humus fraction. 4. Additions of acid to the soil increased the solubility of the nutrient mineral elements. The increases in the solubilities were greatest in the samples that were low in organic matter. 5. Although liming increased the amount of soluble calcium in the soil, it did not decrease the solubility of phosphorus. The additions of lime decreased the solubility of potassium. The solubilities of iron and manganese were too low to be easily measured above pH 7.2 and in only one case above pH 5.0. 6. Additions of acid to the soil increased the solubility of potassium when the reaction was forced lower than pH 5.0. There was a greater increase in the solubility of potassium from the acid treatments in the samples that were lower in organic matter. 7. The solubilities of iron and manganese were increased from additions of acid. Manganese became much more soluble than iron from increased acidity and its solubility was more affected in the samples that were low in organic matter.


HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 751d-751
Author(s):  
John R. Clark

Fertility and soil preparation practices for blackberries from numerous states were reviewed to determine common recommendations. Soil pH was uniformly suggested to be 6.0–6.5, with the use of dolomitic lime commonly preferred for pH adjustment. Organic matter additions were often recommended, using cover crops or animal manures the year before planting. Additionally, the incorporation of P and K the fall before planting was commonly suggested, with rates of application dependent on soil test levels. Nitrogen applications were recommended each year, with rates increasing to the maximum suggested in years 2 or 3. Ammonium nitrate was always the preferred N source. Rates ranged from 28 to 56 kg N/ha for the first year to 67 to 90 kg N/ha for mature plantings, with rates largely dependent on soil type, with sandy soils receiving the higher rates. Application of K was usually recommended for every other year, based on soil test levels.


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