DEGENERATION IN POTATOES.

Dominion, Volume 4, Issue 932, 27 September 1910, Page 8

DEGENERATION IN POTATOES.

SOME EXPERTS' INVESTIGATIONS. During the" past - few : years many 'iii-' .'qriiries have been addressed to. Kew as to the reason why potato, tubers fail to form - sprouts at the proper ' season,: even when placed under. the most favourable condi-. tions for .doing so. ? Last ''spring-'(says ti. - Masse,: in .ithe "Agricultural-,Gazettci [6f ; - [Twmania"),; one 'correspondent. stated tha t- ; tmt'of' seTentj- toris 'bt.'potatoes of: high eipeoiAuy. 1 ' intended for.''seedi" only; ;tons showed signs Of - sprouting, tho; • remainder being disposed.:of,'- at. a serious. Jess, for culinary purposes.[ This condition ®£ things -is. not" confined-'to this t coim-' :.'try.'/•ln'-Germany;serious losses have been; 'sustained owiiig ito: .tho; storility of potato "sets," more' especially of tho kind Known as Magnum' Bonum. . Very- few -of the; eyes; produced, sprouts',, and the - "sets" <at the;; time of .^lifting- 'were■[. not; shrivelled and';dried up. m.' is-the -.case under-nor-mal conditions, but;! on -tho. other,;,hand, : were/'quite solid' and quite -firm, aiid in many cases ;.had ; actually increased;, ,in • size.; In one instance;! where the "sets"' were - graded -'by - a machine before' planting, -an; increase, in t size.'.bf .from', one-half to. three-quarters, had taken place: -. This. jroves."that ■'the';."sets," after;; planting, lad - commenced growth a second 'season, aiid'had the--'starch'', formed; .by .the scanty .femburit of [foliage produced.; Thene\vv tubers.;;forined : by,;, such -plauts'were' sinall and few.'in■ ntimber.;;ln ■ many; : 'dnstoces, ssprouts ;;were[.nbt : formed; - and ■the;"sets"-,remained- intactiri;\.tho;- soil'' < throughout ;the-,season;' ; The loss ; on-thoi jjotitp crop varied from .about 5 per, cent.; ts ;tbtal:Uoss,''. an'd,'. averaged'. from ! ?50 to: 68 Jgt.;cent.';; Investigations '.made, by Dr. :6chleK 'and .Dr; -proved , the, . .absence.-of,imy : specific, -disease,-' and" the '/failure • was,:" in part'. attributed to tha '^practice;- of. growing .;the vsaine .'.kind •[. of potato from sets'' produced; on;: the. spot, lor a long period of time. . . • In' Prance, Dr. Delacroix has described -,the .occurrence", "on^^''a',.larE'e;;scale;".'of : ' ; a; :;Bi^ar/.;stCTiHtyi^ff^tefe.:''-fabers,-'iwhicli'" ~ hb-;callsj"filbsite. in this'.casb; the few '•sprouts' produoed-■ vbecome.vconsiderably : y elongated, remain very slender, and. usu- ' ally, do ; not; 'appearjabove: ground,, and -.-when., they : do,: so, produce only a fow Here-again; there; ■ was: an; absence; of: disease, ;■ and'the : -author; , co'nsiders':th'at?vfilbsite" .is.;due; : to'decad-' enco and loss of vitality,'brought about by ' the 'employment ; or . tho ' vegetative ; 'method Vof. jeOTodu<&on, ; itnose, countrieswhere' .atteii-. fcion- is -paid to the ' of 'improred varieties 'of .-potatoesj ccrtairi-' ■;iidints''KsT6..;.l)affl.-'ebnrantly^kept , . Amongst;;TOfchomay';.be.' : ;;enumerated7-inr.. crcase of crop,; improved 1 flavour,-:smooth* ■ aid -even - surtace, immunity; from disease. With ! the first three -points ; cultivators ihaye'i'surpasMd-. their-vmost .'sariguihe\ expectations,. and Vit; is ; hoped that ..by a. .''strict; appliiiafign :;of <Mendelia'n ; : ;laws,;-V etraiii. of. potatoes immnne..tb» all-Vills.'will be forthcoming.;: >]'■■!• ffi-i : ; iVDnfortunatelyPthe method 6f j selectioii i and'the lines, lollowed; in producing these : anuch-desired".' .improye'rachte .'pofatbes. , ,'have ; :: in> Mniijf'jiustahMs.;': ;also; f ayouredo'ther. uncxpc-ctwl modifications,. which haw 'resiilted in sterility or.the,-failure ;%; tubers. . This ■ failure has been : shown,', by a-'Series of ;6speriments,; ; Mndticted;;at)Kew , iandft : ex-; tending oyer:' three years'/, to bp accompanied .byoa'i'comb'ihation -,nf two; distinct gpedific' coßditionSriCl) "more 'sUt -less-;a'rrest: of[tlio 'fdirtelqpmehtivbfv ;tem,;pf:?the. ; comparative;;; ab?. • eence; of the ferment I 'or: ehzyme' called diastase from the tuber; . • ,--

;-Jt: tubor. as is '.well: known, :.is /the :very,| mufeh; swollen', terminal portion of' ah : oonditio'ns,; those structurcs prcsent in-the; :aljo^ground ; bnlk 'bf a-tuber -consists i mass -of, tissubiorowde'dv with 'staich,"j which 7 '; is used up. iu the formation of :n'e\v:; shoots, the 7 growing..: shoots.^through, certain; por-. .'tibnCof,: : .thei:fibro-Yascular. ( 6ystem^^^ appears to the naked: ey_e; v when* a'tul>e'r is cut across,, as. a;,thin.; lino;-forming./'a. 7 riiig;| situated -some, little 'distarice from ' tho surface of ■ the tuber. 'Branches from; this •ring)pass'outwards tp'the ;,''ey'es"; or:6uh-. ien points/from which 'tlio' sprouts': o'rig-. inate. . Now,the'-^imprbveihent:':'.; 7 inthe', tubers,' from'- the ■-: culinary standpoint, ' .eslection 7 :and': inter-breeding .has i : at::';the''' same-; ,time'-., S been 1 '? accompinied Vby 'v a Mrious..- desenoration-' Kof-! P tho ■ ifibro-! vascnlar, -system;;: 7 in ,'fact,.- in-.-many-pi®s,' ftthat; ? havebeenr'';ejamined/j microscopicaHy,, this system ,is found. to. so ..-'much,' ; rreduced, i: : especially ;inV, .the, 'branches, connecting: :the ; main ;"ring;:with 7 i the; "eyes,'-': [as . to; be;,rendered: 'incapable, i?'' V, c P5 ve yi ; n B .the.-. n'eceMary 7 -^; amount?-of : ; food . from..:; tho tuber -.to •.; tho' growing - shoots. ' Conscfiuently, the .'growing' shoots ■'-?'!;her:.not;; developed, at' all, 7 :.0r:-only .developed" as'iweakly/.fbranches.-'devoid. of . known; fpct - that- a quarter of a.; century ago' stored : potatoes 7: (even .the/' varieties. most - renowned_: for. .v their "mealy" or ilOTiry J qualities) ; wcre apt to becomo ••watery, land unsuitable' : "'.table -purposes during, the : early' spring months. :. Yarioiis 'methods V oftreatment , wbre-diyised -for .preventing,this 'deterio'ra.uon .froin ■ : especially, in _ the/case, of. 7 potatoes; stored on. board - ship ..for; use.' during ' the pro.longed;voyages of that period. This defect is. not apparent'at tho present day,' ;.and .many;' of the .best' kinds'-; remain - liii-' 'changed. in; composition,until midsummer,; or even for a longer period of time. '.' i ; 'During.; the -.; past': three : years; 'a;' series of.experiments have been conducted'with the '.object-f.bf -imparting 7 new' : vigour' 77 to. , potatoes intended for "seed." It must bo admitted ; that the results obtained up, to/the: ; pref«nt;:have'not'been';very: en-' Muraging, . the time, being 7 too, short' to ;'temdve;',the;.;de.teripraHph'.-'wliich'-:has;-beeii-established by a' prolonged period ;qi! tJieless,'/certain', points,' have . been. : noted ■whichmay .prove .to bo of value to fu--tur(> experimenters. • - be due mainly to, the. vegeratiye method or' reprodiiction commonly-followed.; . Eveh;"in the case .9f ;-seedlings,; the parent? of these /must; it least, be: closely related. , ■-: ,