Combination Of Atrazine Research Articles

Effects of the herbicide atrazine and its degradation products, alone and in combination, on phototrophic microorganisms

Toxic effects of the herbicide atrazine and four of its degradation products were determined for growth, photosynthesis, and acetylene-reducing ability of two species of green algae and three species of cyanobacteria. Atrazine was significantly more toxic than its degradation products towards the above test criteria, yielding EC50 values ranging from 0.1 to 0.5 ppm (μg/ml) for photosynthesis and 0.03 to 5.0 ppm for growth. Deethylated atrazine was the next most toxic with EC50 values of 0.7 to 4.8, and 1.0 to 8.5 ppm for photosynthesis and growth, respectively. With deisopropylated atrazine the EC50 values for the same physiological functions ranged from 3.6 to 9.3, and 2.5 to >10 ppm, respectively. Hydroxy- and diamino-atrazine were non-toxic towards most of the cultures tested. Acetylene reduction with cyanobacteria was found to be insensitive to all of the test compounds, except for atrazine, which had an EC50 of 55 ± 15 ppm towardsAnabaena inaequalis. Combinations of atrazine and its monodealkylated products were tested withA. inaequalis and yielded both synergistic, antagonistic, and additive interaction responses, depending upon the actual test system employed.

Interaction effects of permethrin and atrazine combinations towards several nontarget microorganisms.

Interaction de l'atrazine et de la permethrine sur divers microorganismes du sol. Utilisation de champignons, le Pythium ultimum et le Trichoderma viride (action sur leur developpement) et d'une cyanobacterie, l'Anabaena inaequalis (action sur la croissance et la photosynthese)

Effect of Atrazine, Fertilizer, and 2,4-D on Winter Grazing Preferences of Beef Cows on Northcentral Oklahoma Tallgrass Prairie

A good condition, tallgrass prairie experimental area was treated with selected combinations of atrazine, 2,4-D, and NPK fertilizer in spring 1975 and 1976. Crude protein contents in November herbage ranged from 3.401, to 6.3% in treated samples. Untreated herbage contained 5.0% crude protein. Nonlactating beef cows were allowed to graze freely on the area during December, 1976. Utilization of herbage ranged from 43% to 87%. Utilization was greatest on NPK areas (82%), 3.4 kg atrazine + NP areas @SO/O), and 3.4 kg atrazine -I- NPK areas (87%). Decreaser species comprised a larger percentage of the total production on atrazine i- NP, atrazine -I- NPK, and 2,4-D -I- NPK areas than on fertilizer-only areas. Tallgrass prairie treated with atrazine and fertilizer or 2,4-D and fertilizer was preferred by beef cows as winter forage over untreated herbage. There was a 15% increase in herbage utilization for every 1% increase in crude protein in the

Giant Foxtail and Velvetleaf Control in Sweet Corn1

AbstractVelvetleaf (Abutilon theophrasti Medic.) and giant foxtail (Setaria faberi Herrm.) are among the most serious weed problems in sweet corn (Zea mays L.) grown in the north central U.S. While several herbicide treatments have been used to partially control these weeds, the treatments frequently leave soil residues which can injure susceptible crops commonly grown in rotation with sweet corn. Consequently, studies were conducted over a 3‐year period on fields (Plano silt loam, 3.5 to 4% organic matter, Typic Argindoll fine silty mixed mesic) heavily infested with velvetleaf and giant foxtail to compare the effectiveness of 10 herbicides applied alone and in 36 combinations in controlling these weeds. Visual observations of sweet corn injury and weed control were obtained and the sweet corn was harvested to determine the effects on yields. Oats (cv. ‘Lodi’) and peas (cv. ‘NK‐692’), which commonly follow sweet corn in a crop rotation and which are susceptible to residues of common herbicides, were grown over the plot areas the year following sweet corn and evaluated for carryover injury. Of the herbicide treatments included in the study, the best overall weed control and the largest average sweet corn yields were produced by a sequential application of 2.2 kg/ha alachlor [2‐chloro‐2',6'‐diethyl‐N‐(methoxymethyl) acetanilide] applied premergence and 1.1 kg/ha bentazon [3‐isopropyl‐1H‐2,1,3‐benzo‐thiadiazin‐(4)3H‐one 2,2‐dioxide] applied postemergence and by a preemergence combination of 2.2 kg/ha alachlor and 0.6 kg/ha metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5 (4H) one]. Preplant incorporated combinations of butylate (S‐ethyl diisobutylthiocarbamate) with atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] or cyanazine [2‐([4‐chloro‐6‐(ethylamino)‐s‐triazin‐2‐yl] amino)‐2‐methyl‐propionitrile] and preemergence combinations of alachlor with atrazine or cyanazine provided good weed control and satisfactory yields in 2 of the 3 test years. Three‐way combinations of atrazine, cyanazine, and butylate, as well as preemergence combinations of alachlor with bifenox (methyl 5‐(2,4‐dichlorophenoxy)‐2‐nitrobenzoate) or dicamba (3,6‐dichloro‐o‐anisic acid) and a preemergence and postemergence split treatment of cyanazine also showed promise. Preemergence treatments failed to control velvetleaf adquately in 1973 when insufficient rainfall was received, but preplant‐incorporated treatments failed similarly in 1974 following excessive rainfall. Postemergence treatments were typically best for controlling velvetleaf but did not satisfactorily control giant foxtail. The only injury to oats (Avena sativa L.) or peas (Pisum sativum L.) from soil residues persisting until the spring following sweet corn, occurred from atrazine applied at 3.4 kg/ha preplant‐incorporated in combination with butylate.

Chemical Detoxication of Atrazine by Dexon

AbstractThe nonphytotoxic analogs of atrazine (2‐chloro‐4‐ethylamino, 6 isopropylamino‐s triazine) are hydroxyatrazine and protonated hydroxyatrazine. Distinctive infrared bands of these compounds appear at 1620, 1680, and 1740 cm‐1, respectively. By monitoring these distinctive bands of the compounds, it has been demonstrated that in a combination of atrazine and dexon (p‐[dimethylamino] benzenediazo sodium sulphonate) there is a time‐dependent chemical change of some atrazine to protonated hydroxyatrazine indicating a reduction in phytotoxicity of the s‐triazine. A part of dexon‐atrazine antagonism—the reduction of atrazine toxicity to certain plants in the presence of dexon—is due to chemical reaction.

The Interaction of Atrazine and EPTC on Navy Bean

Navy bean (Phaseolus vulgarisL.) treated with the combination of EPTC (S-ethyl dipropylthiocarbamate) and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] developed more chlorosis of the leaves than beans treated with atrazine alone. Navy bean yields in field studies in 1972, were reduced 39% when grown in the presence of 0.55 kg/ha of atrazine and 3.4 kg/ha of EPTC, whereas the single application of either herbicide reduced yields 0 to 14%, respectively. In 1973, atrazine at 0.28 kg/ha did not significantly reduce yields, but combinations of 0.28 kg/ha of atrazine plus 2.2, 3.4, and 4.5 kg/ha of EPTC, reduced yields 40, 30, and 62% respectively. The combination of atrazine and EPTC also reduced plant weight and delayed flower and pod development. EPTC was found to increase wind blast damage under conditions of low relative humidity, high winds, and limited soil moisture. EPTC at 2.2, 3.4, and 4.5 kg/ha reduced the chloroform-soluble leaf extract from the surface of leaves and scanning electron micrographs confirmed that EPTC at 10-6M altered leaf surface waxes. EPTC at 10-5and 10-6M increased the transpiration rate of plants. Increased uptake of14C-atrazine from solution was associated with increased transpiration.

Yellow Nutsedge, Giant Green Foxtail, and Fall Panicum Control in Corn

In a 3-year field study in corn (Zea maysL.), several herbicides and combinations were studied for the control of yellow nutsedge (Cyperus esculentusL.), giant green foxtail [Setaria viridisvar.major(Gaud.) Posp.], and fall panicum (Panicum dichotomiflorumMichx.). Best yellow nutsedge control (87 to 88%) resulted from applications of 4.48 kg/ha of either alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide] preplant incorporated or atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] preplant incorporated plus atrazine postemergence with a phytobland oil. Between 72 to 83% control of yellow nutsedge resulted from applications of 2.24 kg/ha of alachlor, 4.48 kg/ha of butylate (S-ethyl diisobutylthiocarbamate), and combinations of atrazine plus butylate. Greater than 90% control of giant green foxtail and fall panicum resulted from butylate plus atrazine or alachlor; postemergence applications of atrazine resulted in significantly less control of fall panicum or giant green foxtail.

Reducing Herbicide Injury to Sorghum with Crop Protectants

Greenhouse and field studies were used to evaluate crop protectants with herbicides in order to obtain selective, broad-spectrum weed control in sorghum [Sorghum bicolor(L.) Moench ‘RS 626’]. Of the herbicides evaluated alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl) acetanilide] was the only one causing sorghum injury that could be moderated with crop protectants. The crop protectant anhydride (1,8-napthalic anhydride) was most effective in reducing alachlor injury when applied as a seed treatment at 0.5% (w/w). Storage of anhydride-treated seed for 1 year did not increase anhydride damage to sorghum seedlings. Preplant applications of alachlor, incorporated into the soil, caused four times more injury to sorghum than did the same rate applied preemergence. Combinations of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and alachlor did not increase sorghum injury or alter the effects of the crop protectants. In the field, anhydride was the most effective crop protectant used. Crop protectant R-28725 (2,2-dimethyl-3-dichloroacetyloxazolidine) at 0.5% w/w to sorghum seed and at 0.6 kg/ha as a tank mix was effective in reducing sorghum injury at the lower alachlor rates. Crop protectant R-25788 (N,N-diallyl-2,2-dichloroacetamide) was the least effective of those studied; however, seed treatment at 0.5% w/w was more effective than the tank mixes.

Effects of Selected Herbicides upon Growth of Soil Algae

The effects of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), N,N-dimethyl-2,2-diphenyl-acetamide (diphenamid), and N-(p-bromophenyl)-N'-methyl-N'-methoxyurea (metobromuron) upon autotrophic growth of four unicellular green algae were studied. Growth of Chlamydomonas reinhardi Dangeard was completely inhibited by 1 μg/ml metobromuron or 0.5 μg/ml atrazine and was stimulated by diphenamid. Five μg/ml metobromuron were toxic to Chlamydomonas eugametos Moewus, while atrazine and diphenamid had little effect on growth. Growth of Chlorella vulgaris Beijerinck was partially inhibited by atrazine and stimulated by diphenamid and metobromuron. At high concentrations, atrazine or metobromuron inhibited Chlorella pyrenoidosa Chick while growth was stimulated by diphenamid. The results obtained by treating with a combination of atrazine and metobromuron varied greatly with the organism. The effect of these three herbicides upon heterotrophic growth of Chlamydomonas reinhardi also was investigated. Both metobromuron and diphenamid were toxic in the dark. Atrazine had no effect upon heterotrophic growth.

Interaction Effects of Atrazine and CDAA, Linuron, Amiben, or Trifluralin on Soybean Growth1

AbstractGrowth chamber experiments were conducted to study the influence of atrazine, CDAA, linuron, amiben, trifluralin, and combinations of atrazine with these herbicides on the dry matter produced by two varieties of soybeans. Sublethal atrazine treatments did not significantly depress soybean growth as compared to the control. The effect of atrazine in combination with CDAA or linuron was not significant. When damping off organisms were not controlled, severe injury to soybeans occurred in treatments containing amiben or trifluralin at 4.5 ppmw. Sublethal amounts of atrazine appeared to overcome this injury. When seeds were treated with fungicide, the growth of soybean seedlings was depressed by treatments containing combinations of trifluralin and atrazine in proportiont to the amount of atrazine present. Combinations of atrazine and amiben gave growth responses similar to those observed in the earlier experiments, except that pathogen injury was inhibited by the fungicide.