Vol. 15—1961 - NorthEastern Weed Science Society

56.
Progress Report On Potato Vine Killing
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R. L~ Sawyer andS. L. nallyn
This report is a continuation ,of the work covered in previous proceedings
on finding potato vine killing methods which would simulate normal potato
maturity.
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Materials andMet~~s: ·Soaium. sil:iQate .~~. O.2~4" p,;and 8 g~llf>ns- per acre
, '. ';_ ,~s added to SO~\UI1 a,fsellit.~_a~ 0,2 ,4. Pand 8 pounds
per acre. Plpts, were three .rOwSwide -;and.30feet J.opg with 4replications.
Katahdin potatoes were plantedApril'lll..Ma.terials were applied on August 8
before vines bad started'to go' dO.W1l, 'but aft~ ~,goodf,ie,ld of tu);,ers was under
the vines.. MateriaIswerera1iedO throl1gh 10 £~r-:speed'C?f kill f~ve, times in the
next three weeks With' 0 giVing norma1, .fQ4~e,5; cOlllPlete leafkUl and 10, both
leaf and stem kill, The rating glve'nintlle table is'an average for the five
readings. At harves'tt. on ,Sep~1'lber a"tubers .were rated for degree of skinning,
1 throt,tgA 10 .With" 1 ~1n,dicating.no ~k~ andlO~e,vere skinning;, 'Ratings of
7 and above wereres~rved tor s&mples, wher~.sk;iiwin8:-'WOuld detrac~ from grade,
Tubers had passed. over a rc:>U,grader ba.tpre rating It , '. r..
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Results and1):iso~sio~:'These~fmut8 c1e&r~' ind10ate that the ~ast kill of
. ' . '. , sodi~m, '€irsenit~· is .hurting~h ... ·internal· quality •and
exterior quality' ,of potatoes. ,.Altbo:ugh,the~~sultsare not as great as in 1959,
sodium silicate 't'endsto .coun~ct tbedetrilntIDtaJ. :e.f'fects of sodium arsenite
at the dosages riecessaryforadequa;t~vine kill., '
As in the previous year sodium 'silicate ~low~d downthe~; action of
sodium arsenite. 'l'his was mst, ~ppllI'ent ~:t the high do~ag&pl of sP4iull'l arsenite.
The specii"io :g~avities tended :to ,be·best ,at-lhe bigh dosages of "Pdium silicato.
Skinning tended to~ ]e aat attp.~ high :etos~f3s of ,sod~um ~il:l.eatp. Th~
specific grav~ti decreased as the, dosage otsodiulIl arsel').ite .waff ipcreased.
Slcti'ming 't1aS l~ast Wh~re pot~¥>esrb&d nO.sodiumarsemteor at t¥low do.age.
of'sodium arsenitel'The .P9ta~e $es 1.nt~e piotsbad gone to. normal maturity.
The materials were applied' early' enough so that high dosages of sodium a~enite
decreased yields.
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Long Island Vegetable Research Farm, C9:rnell University" Riverhl';nld,'New York
Paper No-. 447, De~t of Veg~~le Cito~,( Corneiltrni verst tY"IthaCa, N. Y.
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