Vol. 16â1962 - NorthEastern Weed Science Society
Vol. 16â1962 - NorthEastern Weed Science Society Vol. 16â1962 - NorthEastern Weed Science Society
450 OJJJCfIVES A major aim of the toxicolDC!aal~ttudles con4~ br.the Institute during 1961 has been to determine Whether or not the field application to' milfoil of attaclay pellets impregnated with the butoXT_ethanol_ester of 2,4-D causes lethal effects upon species of~ommercial importance that occur in the Chesapeakearea. A second objective was to determine if herbicide residues are present lal tissues' of ·food sp.des held in experi. , mental plots durinc aad after treaUlent. An addit1_1objectivehas beellc the accumulation of"dati. concernliii,~the etfect of treatment on other aquatic aniJilals and plants natlvelto' the treated ar ... ~~ ~ ,.:,X ~ -, '1 ~, This particular f'ormulatiOl1of a,4-Dwas Ielect4citor the study be;.;·':: cause ear11er research .(Beaven,1,601Steenis andStotti., 1961) had' ' demonstrated its etfectiveneu and apparent safet", •• used'for mllfolli control in local tldalareas. '1'" . fl' ;' rl ~ LOCATIONOFUPElUMENTALPLO!l'Sj I ·i.- -"t' \ .' 'fl. Important commercial:fisherits!or the easte·rn-,zofster (Crassostrea rM:inica), the blue crab (CallipHttssapidus )ud.-ahe softshell clam M arenaria) occur in the saltier waters invaded bVmilfoil. For this reason, the primary area selected for st1,1dywall..tb.t1,lower PotomacRiver where these three species occur. Field trips were madein early spring to selectll1llfoll irifestedcreslts:ol" 'coves where onwcll. plots could be laid out. It wasessentia.l that [the.e be well sheUtJ!edand subjected to a minimumof water dispersal from:tlde and wind moveMnt. The three most suitable Potomactributaries meetlng·these specificatloDs were St.Patrlck Creek and 'Wblte Neck Creek on the Ma17landshore amULOwerMachodocCreek on the Virginia slde.In each of ,these, oysters aril:planted~ commercial crabbing and f1shlngarepracticecl taM.'beds of naUte,sottshell clams are present although not exploited commercially. An additional area, Dundee Creek near the head of the Chesapeake, was chosen for observations in fresh to barely brackish tidal water. ' :':; "J. r:,.," In the'potomacexperiments't~l'ee replications 9'l-itreatments were \", madeduring late spring at 3Ellbu:,acid equivalentdt 2.4-D per acre. 60 Ibs. AElAandof'untreated control plots. A single plot treated at th.'~ rate of 120 Ibs. AE/Aand a fourth control plot .werf,lIalaolOCated in this;' area. These provided observations of applications, madeduring the most favorable period for herbicide effectiveness, at double and quadruple the quantity shownby'priorexperiBlen\t,(30 Ibs. AE!A):te,beaufficient for . good contro~. SUbsequentobse~at10's this lear (Slfenls et al 1962) have shownthat over large plots, 20 Iba. :AE/Acan supptijiAlillfollunder proper conditions of application. ;:.;." J\'" : Each one-acre plot was roUBblf"square in shapeJ.-d"contained dense" beds of milfoil. Plots were measured with floatingpolTethylene rope and' corners markedby stakes set firmly in the bottom aDd projecting eight or more feet above the surface. Each plot was designated by a number. Average depth was apprOXimately3 feet with tidal fluctuations of a little
more than 2 feet. ExceptionalUdes several feet ~yond the normal ran~ occasionally occur. ' Nosingle creek in the lower Potomachad suffIciently extensive mil. foil beds to accommodateall ofth~ replicated plots and provide adequate buffer zones betweenthem. Tbethree creeks selected were as nearly alike as possible but had slight differences in salinity-and in other characteristics of minor importance. Since it was moredesirable to replicate measurementsof the differences in 'mortality betw~n groups of animals etposed to zero, 30and f:IJLbs, AFJAof 2,4-D than tOrepl1cate identical! treatments, a complete series of the three treatmen~swas placed in each creek. Hence, plot numbersfor one each of thethfee treatments were chosen separately and at randomfor the individual' .creeks. The site of· 1 the 120 Ibs. AEtAtreatment and'of a control were¢rawnfrom plots near J the mouthof \'lhite NeckCreek. Plots for each typ~f of treatment in the i low salinity habitat of DundeeCreekalso were chal$enat random. " WATERTElJ,FERATURE ANDSALINITY Collection of certain envlronmentaldata begaa·in early spring when the plot sites were se~ected. ~ing the period o~test-animal exposure, the salinity of the MarylandPotomactributariesu~ually varied between 7 and 9 parts per thoulland, whllethat of plots in]he upper portionot the LowerMachodocwas ap~roximatelY two parts lo~r. salinity in Dundee Creek remainedwell under 1 ppt or essentially tr~~h. ThePotomacvalues were about twoppt below the seasonal normal tpr that area. j' . Water temperatures rose irregularly during the study period and generally were below seasonal normal. At the time of.herbicide application in the MarylandPotomactributaries (May29-June I), water temperatures ranged between18.5° and 21.5° C. , During the preceding week, they ran from one to twodegrees higher. Whenthe Machodoc:plotswere treated on June 7, water temperatures were unrecorded'at the time of application but were ranging in the low to mid.twenties as determined from parallel data. During the subsequent period of observation, water temperatures ranging up to 27.5° were recorded in the Potomacplots. In DundeeCreek the water temperature was l6.~o C whenherbicide was' applied on May20 at 5:30 A.M. Higher temperature~ had occurred at this location a tew days earlier and on'May21 the tem~ature was 18.5°. No further temperature readings"were taken in the'to%\cological study plots' at this location. " HOLDING QFExpERIMENTAL ANIMALS In each treatment plot, cages of experi~ental animals were placed near the center, about 10 ft. outside the plot boundaryand at a point about 200 ft. outside the plot. Oncontrol plots, animals were held near the center. Limitations of time and personnel did not permit replication of cages at each holding site. 4.51
- Page 399 and 400: 399 The treatment consisted of appl
- Page 401 and 402: 401 FIELD PROCEDURES Although. the
- Page 403 and 404: 403 In the light of these data it a
- Page 405 and 406: 405 ...·1!MLE I SAMPLECHARACTERIST
- Page 407 and 408: 407 , '.". '.·',',~'l~rL,i;'. "\"
- Page 409 and 410: dltterent l"atespacaoreand"~"at thr
- Page 411 and 412: 411 RESULTS ireatmentettect was det
- Page 413 and 414: , 413 ;. ' "1 ' "':j " • made wit
- Page 415 and 416: ( ( . Table 3. Effectiveness on Spe
- Page 417 and 418: 417 FENURQlt,A PROMISINGNEWTOOL FOR
- Page 419 and 420: There are a number of reaso~ for un
- Page 421 and 422: .n_ots, "'hhin a few months after:
- Page 423 and 424: sater method ot tree-killing close
- Page 425 and 426: Material ~izone is a,mixedf~g.. t w
- Page 427 and 428: 427 On November 16, 1961, at the en
- Page 429 and 430: CHBMI-THINNINGWITH,AIrlINES IN THED
- Page 431 and 432: These tests show once aaaiJithe nee
- Page 433 and 434: Th:Ls ch!~ca1. tx'eatme:n1!_1IhClJ.
- Page 435 and 436: : if.. . ' A Comparative Study of t
- Page 437 and 438: 'j 437 petioles, now elongated,f'or
- Page 439 and 440: Helisoma, Menetus, fhYSa andValvata
- Page 441 and 442: i s. The benth1c populat1Q~ W¥", O
- Page 443 and 444: 443 Eurasian. wa~lfoil a W8t.f~~ ap
- Page 445 and 446: Empb4sis was on testing DOD-volatil
- Page 447 and 448: 447 . , , -. I':'V'est~a.ti
- Page 449: FIELDOBSERVATIONS UPONESTUARINE ANI
- Page 453 and 454: TABLE1. Responseof oysters t~ diffe
- Page 455 and 456: In the'Dundee Creek series. ,one of
- Page 457 and 458: workers. springer (1961) cite8& num
- Page 459 and 460: OBSERVATIONSONTHE OCCURRENCE' ANDPE
- Page 461 and 462: 461 TABLE! Chemical Water QuaU1?::r
- Page 463 and 464: TABLEIII Threshold Taste and Odor C
- Page 465 and 466: (1.1-) Burttschell, R.H. , et al.,
- Page 467 and 468: Code A - seeded June 29 B - seeded
- Page 469 and 470: SUIIIIJ~, ~ Conclusions 5' 469 The
- Page 472 and 473: III. Average turf scores l' of thre
- Page 474 and 475: 474 PIft'J'OTOXICBlFBQTS'QJe'CBRTAI
- Page 476 and 477: 476 MERIONBLUEGBASS• T!BATANDsgD
- Page 478 and 479: 478 In general. the treatments appl
- Page 480 and 481: 4BJ days follow:lng the ohemical tr
- Page 482 and 483: ') ') ' :_B!.ue~s•. Fescue au:l~"
- Page 484 and 485: :". ',J P~E~ C!',. O~.C~G~S 'F.~HEM
- Page 486 and 487: Lima and ferd'1izer applications sh
- Page 488 and 489: 4es 1'.o~~1ty, ", .ewf!r''''rsenc.
- Page 490 and 491: } ) Table 1. Besu):ta.Qf 1961 pre-e
- Page 492 and 493: 492 corresponding plots on este.bl1
- Page 494 and 495: 494 ae.u!s,'I!IIDi,cua.:Lon leUllll
- Page 496 and 497: 496 D±!3pa,~n~ Resul te)I? .,l-ta,
- Page 498 and 499: 498 1 . 1 J. E. Gallagher and n. J.
more than 2 feet. ExceptionalUdes several feet ~yond the normal ran~<br />
occasionally occur.<br />
'<br />
Nosingle creek in the lower Potomachad suffIciently extensive mil.<br />
foil beds to accommodateall ofth~ replicated plots and provide adequate<br />
buffer zones betweenthem. Tbethree creeks selected were as nearly alike<br />
as possible but had slight differences in salinity-and in other characteristics<br />
of minor importance. Since it was moredesirable to replicate<br />
measurementsof the differences in 'mortality betw~n groups of animals etposed<br />
to zero, 30and f:IJLbs, AFJAof 2,4-D than tOrepl1cate identical!<br />
treatments, a complete series of the three treatmen~swas placed in each<br />
creek. Hence, plot numbersfor one each of thethfee treatments were<br />
chosen separately and at randomfor the individual' .creeks. The site of· 1<br />
the 120 Ibs. AEtAtreatment and'of a control were¢rawnfrom plots near J<br />
the mouthof \'lhite NeckCreek. Plots for each typ~f of treatment in the i<br />
low salinity habitat of DundeeCreekalso were chal$enat random. "<br />
WATERTElJ,FERATURE ANDSALINITY<br />
Collection of certain envlronmentaldata begaa·in early spring when<br />
the plot sites were se~ected. ~ing the period o~test-animal exposure,<br />
the salinity of the MarylandPotomactributariesu~ually varied between<br />
7 and 9 parts per thoulland, whllethat of plots in]he upper portionot<br />
the LowerMachodocwas ap~roximatelY two parts lo~r. salinity in Dundee<br />
Creek remainedwell under 1 ppt or essentially tr~~h. ThePotomacvalues<br />
were about twoppt below the seasonal normal tpr that area.<br />
j' .<br />
Water temperatures rose irregularly during the study period and generally<br />
were below seasonal normal. At the time of.herbicide application<br />
in the MarylandPotomactributaries (May29-June I), water temperatures<br />
ranged between18.5° and 21.5° C. , During the preceding week, they ran<br />
from one to twodegrees higher. Whenthe Machodoc:plotswere treated on<br />
June 7, water temperatures were unrecorded'at the time of application but<br />
were ranging in the low to mid.twenties as determined from parallel data.<br />
During the subsequent period of observation, water temperatures ranging<br />
up to 27.5° were recorded in the Potomacplots.<br />
In DundeeCreek the water temperature was l6.~o C whenherbicide was'<br />
applied on May20 at 5:30 A.M. Higher temperature~ had occurred at this<br />
location a tew days earlier and on'May21 the tem~ature was 18.5°. No<br />
further temperature readings"were taken in the'to%\cological study plots'<br />
at this location. "<br />
HOLDING QFExpERIMENTAL ANIMALS<br />
In each treatment plot, cages of experi~ental animals were placed<br />
near the center, about 10 ft. outside the plot boundaryand at a point<br />
about 200 ft. outside the plot. Oncontrol plots, animals were held near<br />
the center. Limitations of time and personnel did not permit replication<br />
of cages at each holding site.<br />
4.51
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