Vol. 16—1962 - NorthEastern Weed Science Society

Vol. 16—1962 - NorthEastern Weed Science Society Vol. 16—1962 - NorthEastern Weed Science Society

08.06.2015 Views

302 Selective,' cOntrol.of ~s~ (PeD1C1D'o~JJare)in a 8UIIIDer, ' seed1ni ot ~a1iaW&8 obt " ",' pre-emergenoe 'appllcationa ot ~, dacthal &QddipbeneiJdd aM !rc!n:~rgeneea~ationao! 2,4-m • DNBP. ,DiPb~ in particular:,~ts turtber c~.. tion on eltelte.. DNBPwas selective only at the lower rate usedfbi is.), G34696caUsed 8CIIIl8 Jielt;\ ZI«1uct1on but merits furthIS:' tesij.ng, blr~cl1Dg lan:r rat,.., DitU'01'1,trit,Luralin and 2,4~ abOwDO pranise torp.emergence use ori ' eltalta. ",,, .,' " The OoOlJe:rat:lCllof the tollCllld.ng oompanies ift:r~ chemioals 1.' aoknowledgedl The Dow Chemical" CO.J AmchelllPro

The results were similar to those obtained previously. There was more arsenic in the bluegrass grown in the 1 and 100 ppm P nutrient solutions than in that grown in the 10 ppm P nutrient solution.. Likewise, crabgraas grown in the 1 ppn P nutrient solution had a much higher concentr~tion of arsonic than crabgrass grown in the higher phosphorus nutrient solutions or thall bluegrass grown in the 1 ppm P nutrient solution. ljlir~~ Research Officer in ••Weed Control, Field Crops Section, Canada Department of llgriculture Research Station, Fredericton, New Brunswick. formerly Research Ass; st.",11t.-: DAn",..t.mAYlt, "f' ","'10m 0.,.""" l~,,+"~.. o EFFIDJTOF PHOSPHORUSON THEUPTAKEOF TRICALCIUMARSENATE BY BWmRASS LNDCRABGRASS C. Fred Everett l and Richard D. Ilnicki 2 ABSTRACT The phosphorus level in a soil is considered to be one of several factors which influence the phytotoxicity of arsenic. 303 An established Kentucky bluegrass sward was fertilized in the fall with three rates of phosphorus: 0,75 and 150 lb. F20S/a. The soil was a Nixon sandy loam which was low in available phosphori\ls. Two pH levels, S.O and 6.0, were established by additions of sulfuric acid. "Low lime" tricalcium arsenate at 0, 3, 6 and 9 lb. of As per thousand square feet was applied the following March. Grass was harvested in June and August of the same year. The arsenic and phosphorus coneerrtr-atdona in the grass were not affected by the additions of phosphorus to the sward. The higher pH slightly decreased the arsenic content of the grass. The application of higher rates of arsenate slightly increased the ars~nic concentration. There was no visible sign of injury to the bluegrass. In the greenhouse Merion blue'grass and crabgrass plants grown in a nutrient solution with 10 ppn of phosphorus were preconditioned for one week in nutrient solutions having 1, 10 and 100 ppm of phosphorus. "low" lime" tricalcium arsenate and sodium arsenite treatments were applied and the plant tops harvested 24, 48 and 72 hours later. High levels of phosphorus in the zmtrient solution reduced the phytotoxicity of the arsenate treatments to practically nil, but they did not influence the phytotoxicity of the arsenite treatment. The phosphorus concentration in the bluegrass tops grown in the 100 ppn P nutrient solution was five fold greater than that in the bluegrass grown in the 1 ppm P nutrient solution. Bluegrass from the 1 and 100 ppn P nutrient solutions contained two to three times as much arsenic as bhiegraae grown in the 10 ppm P nutrient solution. On the other hand, crabgraae had the most arsenic when grown in the 1 ppm P nutrient solution and by far the least when grown in the 100 ppn P nutrient solution. "low lime"6tricalcium arsenate was synthesized in the laboratory and tagged with As7. This was applied to nutrient solutions as above. The bluegrass and crabgrass toPll. 6were harvested 9, 18 and 36 hours later, digested and counted for As7•

302<br />

Selective,' cOntrol.of ~s~ (PeD1C1D'o~JJare)in a 8UIIIDer, '<br />

seed1ni ot ~a1iaW&8 obt " ",' pre-emergenoe 'appllcationa ot ~,<br />

dacthal &QddipbeneiJdd aM !rc!n:~rgeneea~ationao! 2,4-m •<br />

DNBP. ,DiPb~ in particular:,~ts turtber c~.. tion on eltelte..<br />

DNBPwas selective only at the lower rate usedfbi is.), G34696caUsed<br />

8CIIIl8 Jielt;\ ZI«1uct1on but merits furthIS:' tesij.ng, blr~cl1Dg lan:r rat,..,<br />

DitU'01'1,trit,Luralin and 2,4~ abOwDO pranise torp.emergence use ori '<br />

eltalta. ",,, .,' "<br />

The OoOlJe:rat:lCllof the tollCllld.ng oompanies ift:r~ chemioals 1.'<br />

aoknowledgedl The Dow Chemical" CO.J AmchelllPro

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