Influence of Formulation on the Activity and Persistence of Pendimethalin

2004 ◽  
Vol 18 (2) ◽  
pp. 397-403 ◽  
Author(s):  
Ageliki S. Hatzinikolaou ◽  
Ilias G. Eleftherohorinos ◽  
Ioannis B. Vasilakoglou

The activity of emulsifiable concentrate (EC) formulation of pendimethalin was studied using a petri dish bioassay based on root response of corn, oat, sorghum, and sugar beet grown in soil. Furthermore, the oat bioassay was used to determine the activity of EC, microencapsulated (ME), and water-dispersible granule (WDG) formulations of pendimethalin. Also, field persistence in soil of these pendimethalin formulations was studied with petri dish and pot bioassays, based on root response of oat and sugar beet. All bioassays indicated that activity of all pendimethalin formulations was increased with increasing herbicide concentration. In silty clay loam soil, oat and sugar beet exhibited the highest sensitivity to EC-pendimethalin concentrations and corn the lowest; sorghum showed intermediate herbicide sensitivity. EC of pendimethalin showed the highest activity on oat and ME pendimethalin the lowest; WDG-pendimethalin showed similar activity to that of ME pendimethalin. Field persistence was significantly increased with increasing rate of application, but it was slightly increased by the ME formulation.

Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 579-585 ◽  
Author(s):  
Ioannis B. Vasilakoglou ◽  
Ilias G. Eleftherohorinos

Activity, adsorption, mobility, and field persistence of one emulsifiable concentrate (EC) and three microencapsulated (ME) formulations of alachlor were studied with petri dish bioassay, based on root response of oats grown in sand or soil. Both bioassays indicated that activity of all formulations was increased with increasing herbicide concentration. EC-alachlor in sand showed the highest activity, while ME-alachlorLand ME-alachlorA, the lowest; the activity of ME-alachlorCwas intermediate. In silty clay loam soil, EC-alachlor had the highest activity, while ME-alachlorLhad the lowest; and ME-alachlorAshowed intermediate activity and was similar to that of ME-alachlorCMore alachlor was adsorbed on the soil or remained encapsulated (not biologically available) after ME-alachlorLand ME-alachorAapplication compared to EC-alachlor. An intermediate amount of alachlor was adsorbed or remained inside the capsules when the ME-alachlorCformulation was applied. Greater amounts of alachlor were leached through a silty clay loam after EC-alachlor application compared to the three ME-alachlor formulations. Biologically available alachlor was not detected below 15 or 10 cm after application of EC- and ME-alachlor formulations, respectively. All alachlor formulations applied alone or in mixture with atrazine showed similar field persistence. Biologically available alachlor was not detected in the 0- to 10-cm soil depth 30 d after their application. All alachlor formulations applied alone gave excellent control of redroot pigweed and black nightshade, but only partial control of jimsonweed. None of the herbicide treatments showed any detrimental effect on corn, and all of them increased corn yield to the level of weed-free control.


Author(s):  
Mohammed Aajmi Salman ◽  
Jawad A. Kamal Al-Shibani

Beneficial microorganisms play a key role in the availability of ions minerals in the soil and use Randomized Complete Block Desing ( R.C.B.D ). The objective of this paper to the study effect of the of biofertilizer and miniral treatments on availability of NPK for crop corn zea mays L.Two types of biofertilizer are Bacterial Bacillus subtilis and Fungal Trichoderma harianum. Three levels of potassium fertilizer are (2.9533, 0.4000 and 2.9533). A field experiment in fall season of 2018 Has been conducted in silty clay loam soil. The experimental Results indicated that Bacillus and Trichoderma inoculation separately or together Have made a significant effect to increase in the availability of N P K in the soil compare to other treatments. The grain yield is where (2.9533, 0.4000 and 2.9533) of bacterial and fungal bio-fertilizer and potassium fertilizers respectively as compared to the control.


2008 ◽  
Vol 88 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Hafida Zaher ◽  
Jean Caron

The slaking process after rapid wetting is a key factor controlling soil structural stability in dry soil, and an understanding of the relative importance of the different mechanisms involved in slaking may help in the design of management strategies aimed at maintaining a stable surface soil structure. Slaking has been linked to, among other factors, rapid pressure build-up in aggregate, and previous work has emphasized the role of organic matter to hamper that pressure build-up, possibly due to hydrophobicity, reducing rapid water entry within aggregates and hence the build-up. This study emphasizes this latter aspect linked to slaking. The evolution of the intra-aggregate pressure, the matter lost by slaking and the expelled air after rapid wetting of two soils of different textures (clay loam soil and silty-clay loam soil) amended with different types of paper sludge were studied. Hydrophobicity effects were also studied using a tensio-active solution. The results of these experiments showed that when aggregates were submitted to sudden wetting, those treated with paper sludge had an improved resistance to the destructive action of rapid wetting. The lower pressures measured in the aggregates from the amended soils and having less slaking resulted most likely from slow water entry and reduced swelling. Detailed investigation on the link between hydrophobicity and water entry revealed that the true hydrophobic effect (modification of contact angle) was non-existent for the silty-clay loam and minor for the clay loam. This study, rather, suggests that changes in the water potential at the wetting front following organic matter addition and aggregate immersion most likely depend on pore occlusion and on changes in pore surface roughness. Key words: Aggregate stability, organic matter, slaking, pressure, swelling, wettability


1995 ◽  
Vol 20 (1) ◽  
pp. 287-287
Author(s):  
F. P. Baxendale ◽  
A. P. Weinhold ◽  
K. Von Bargen ◽  
R. D. Grisso

Abstract This study was conducted in Lincoln, NE on a golf course fairway. The turf (100% Kentucky bluegrass) was maintained at a mowing height of 5/s inches. Thatch accumulation (finger compressed) in the plot area was 0.5 to 0.75 inches. Field conditions at the study site were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6.7; water pH, 7.0. Soil moisture was maintained at approximately 17% by weight, throughout the study. Plots were 40 inches × 15 ft and the experimental design was a RCB with 3 replications. Insecticide treatments were applied on 23 Aug 1994 using either a Cushman prototype subsurface applicator designed to place insecticide granular treatments at the soil-thatch interface (avg depth 0.75 inches), or a Gandy 24H12 drop spreader. Following applications, plots were irrigated with 0.5 inches of water. Posttreatment precipitation totaled 0.42 inches. Treatments were evaluated 21 DAT on 13 Sep by removing from each plot three, 8-inch diam turf-soil cores (1.05 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs. Pretreatment counts indicated 10-40 SMC/ft2 with 80-90% in the third instar stage in the test area.


Weed Science ◽  
1974 ◽  
Vol 22 (6) ◽  
pp. 600-603 ◽  
Author(s):  
W. L. Barrentine

The competitive effects of common cocklebur (Xanthium pensylvanicumWallr.) on soybeans[Glycine max(L.) Merr. ‘Lee 68′] were studied on Dundee silty clay loam soil from 1970 to 1972. Full-season competition by common cocklebur at 3,300, 6,600, 13,000, and 26,000 plants/ha reduced the 2-year average soybean seed yields 10, 28, 43, and 52%, respectively. Competition from common cocklebur at 100,000 plants/ha for 4, 6, 8, 10, 12, and 16 weeks after soybean emergence reduced soybean seed yields 10, 36, 40, 60, 80, and 80%, respectively. A reduction in soybean stand occurred after 12 or more weeks competition, and an increase in soybean plant height occurred after 10 or more weeks competition. When common cockleburs were removed during the first 4 weeks after soybean emergence, no further removal was required to obtain maximum soybean yield. Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide] at 1.1 to 2.2 kg/ha applied over-the-top of common cockleburs and soybeans was as effective as hand removal in terminating competition provided common cocklebur plants were not flowering.


2016 ◽  
Vol 11 ◽  
Author(s):  
Angela Libutti ◽  
Massimo Mucci ◽  
Matteo Francavilla ◽  
Massimo Monteleone

Biochar incorporation into agricultural soils has been proposed as a strategy to decrease nutrient leaching. The present study was designed to assess the effect of biochar on nitrate retention in a silty clay loam soil. Biochar obtained from the pyrogasification of fir wood chips was applied to soil and tested in a range of laboratory sorption experiments. Four soil treatments were considered: soil only (control), soil with 2, 4 and 8% of biochar by mass. The Freundlich sorption isotherm model was used to fit the adsorbed amount of nitrate in the soil-biochar mixtures. The model performed very well in interpreting the experimental data according to a general linear regression (ANCOVA) statistical approach. Nitrate retention in the soil-biochar mixtures was always higher than control, regardless the NO<sub>3</sub><sup>-</sup> concentration in the range of 0-400 mg l<sup>-1</sup>. Different sorption capacities and intensities were detected depending on the biochar application rate. The highest adsorption capacity was observed in the soils added with 2 and 4% of biochar, respectively. From the results obtained is possible to infer that nitrate retention is higher at lower biochar addition rate to soil (2 and 4%) and at lower nitrate concentration in the soil water solution. These preliminary laboratory results suggest that biochar addition to a typical Mediterranean agricultural soil could be an effective management option to mitigate nitrate leaching.


1959 ◽  
Vol 39 (1) ◽  
pp. 76-85 ◽  
Author(s):  
H. C. Korven ◽  
S. A. Taylor

An apparatus is described which involves the use of a small thermocouple, cooled to the dew point by the Peltier effect, as a means of determining the relative activity of water in soils.Thermocouples were calibrated over a series of sulphuric acid solutions immersed in a constant temperature bath controlled to within 0.003 °C. The temperature of the bath for all readings was 25 °C. Readings were taken over Benjamin silty clay loam soil samples that had been brought to desired soil moisture relative activities by the pressure plate and pressure membrane methods. The following conclusions were reached:1. The thermocouple technique shows promise as a laboratory procedure for determining the relative activity of water in soils.2. The majority of the results showed a gradual lowering of the readings with time. This was overcome at the expense of speed by treating the thermocouple with a plastic spray paint.3. More study and testing are required before the technique can be considered a completely satisfactory procedure.


1997 ◽  
Vol 22 (1) ◽  
pp. 355-355
Author(s):  
F.P. Baxendale ◽  
A.P. Weinhold ◽  
K.A. Weinhold

Abstract This study was conducted in Lincoln, NE on a golf course fairway. The turf (20% Kentucky bluegrass and 80% perennial rye) was maintained at a mowing height of 11/16 inch. Thatch accumulation (finger compressed) in the plot area was 0.375 to 0.50 inch. Field conditions at the study site were: soil type, silty clay loam; soil organic matter, 4%; soil pH, 6.2; water pH, 7.0. Environmental conditions at the time of application were as follows: soil moisture 12% by wt.; air temperature 72°F; soil temperature 72°F; relative humidity 43%; wind direction and velocity 6° at 7 mph. Plots were 6 X 10 ft and the experimental design was a RCB with 3 replications. Insecticides were applied once on 9 Jul and twice on 11 Jul. Liquids were applied using a CO2 sprayer with a TeeJet® 8002 nozzle at 30 psi and delivering 2 gal/1000 square feet. A pre-calibrated Gandy 24H12 drop spreader was used to apply granular insecticides. Post-application irrigations were applied as follows: 09 Jul application, none; 11 Jul, first application, 0.35 inch; 11 Jul, second application with syringe, approximately 0.125 inch. Normal irrigation was resumed after 48 h. Precipitation between application and evaluation totaled 11.3 inches. Treatments were evaluated 57 DAT on 4 SEP by removing from each plot three, 8-inch diam turf-soil cores (1.05 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs. Insecticides were applied prior to the onset of masked chafer oviposition.


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