A POTATO DOCTOR..

Dominion, Volume 2, Issue 600, 31 August 1909, Page 8

A POTATO DOCTOR..

MR. KIRK IN TASMANIA. INTERVIEWED BY HOBART, NEWSPAPER, The arrival of the New Zealand Government Biologist, Mr. T. W: Kirk, P.L.S., in Hobart, to,investigate,the potato disease scare,''seemß to have:given heart to Tasmania'n potato growers. The gloom into which the potato troubles had cast Tasmanian growers was visible enough in a recent editorial, article in the Hobart "Mercury;". This journal, in announcing ' the, total 'collapse of the potato industry: in ■ the infected fertile north-west, said:—"lt is probablo, that tho'blightrstricken districts of Tasmania: will have to cease the growing of potatoes for some seasons. The closing of the doors'(of. Australian ports) will have the'effect of stimulating" the farniers'in'cach Australian' State to supply their' ovra iriarket. Therefore it would be well forth©' Council of Agriculture to go promptly into the question of new crops."' The."Mercury" sug-' gestsgrej' was,'hemp,'dairying;,'and' -mixed farming,*ana continues: "ItWill be found that .never-ngaih' will the north-west farmers be able ,to 'plant such large areas under potatoes." : ■-,;■;

What: they Think of our Biologist. -.■■■■;■ A reporter of the "Mercury" was;-, among those who interviewed Mr.'Kirk on arrival, and he describes/Mr. .Kirk/as. "a vegetable pathologist with/'a 'very high"reputation both, in America and Australasia, ; and the author'. of several works on plant and other diseases. Ho is a,very affable man, ready to impart information to any interested inquirer in' reference.:to his particular line of wprb, and has ,brong;ht ;with-,'him.'a. large number of glass jars .contain-! ing: specimens of - all manner of diseases and .pests/attacking the potato, on;alL of-which he is ever ready, to converse-in' a very','instructive ibanner, and" to state the most up-tf-pdate methods of combating these troubles, some .of which means ,ho has. himself'/discovered jjind proven effectual" : ,: ■ . ;In the: course of tho interview Mr. lurk described .the' nature and cure of various potato ills; and as these will be:troubling New/Zealand' growers shortly, ; Mr. Kirk's statements, will : posset'-"a' New/ Zealand . interest r also. VWhen asked if he found spraying with Bordeaux misthro" effective against Irish:.blight in New- Zeala:id,:Mr. Kn-k.rephed:— ; . ''Yea, v^ry-:successful.• But vther©, aro- sotD6 who' grdw:.potatoes in-.New -.Zealand .w'ho will 'still - tell'you ; that > epraying is: -no good, : just nei '-I ( -suppose, .there are-some/frhit-growers in ..Tasmania, who ,will;say/that/spraying' for; the Aodlin/rooth /has'rio- .effectv'- ■/ • v Do : yon :, quarantine..- infected ;< districts ?— "No." ' 1 . j \ /Is. spraying, made.compulsory?—;'No, not so far, but'the Department has tho power to make it compulsory. : ;' '-': ' IKow many times do- yonvspray r—, ITiat depends on the season,: and: the -weather.. If tho, weather ! -is wet, three to .-six times.' In ;/a dry. "scasonv.'tidce'.or ;thrce; ; timra."

The £. s. d. of.Spraying. • ■ What docs it' cost vfor'. several .successive Sprayings of.'a otop?"-"I'iv8,,shillings to.'ss.' 9di; per ticrei' withva big machine. Ofcourse,' if; a liiari, ; 'only - uses a> lcnapsack .Sprayer over a, good-size 'paddock-:.it; fcostsi'more.', .'.Often .. a grower* does not ;stn'rt spraying : I nntil' tho diseasa '.has. got -. a,' good hold,'.'.and. that is- another, mistake made. is to be looketl upon-as a' measure, : and-.accordingly the first spraying nipt bo' applicd/.before.'finy disease .appears;' ' It: is alfio Uniportaht.'Jt'o 'use; . tho' proper spraying nozzle, which : is- : the ■ 'Cyclone' liozzlo,..with .which - tho under, surface, of-the loaves is reached."-,' y<-: : '.v'Vv ;',(At' .what: period of growth; is the .first spray-, iilg -.done ?—"Wlion. the potato / haulms,' are between six and nine inches high, -and .again when in 'floH-er.'. If the ,disease is bad;, and the | wcatheSwet.'/it 1 :ii(' : necessary to•' spray bftener,'. at 'intervals 1 of- about' ten days. - Should :rain' i-fali;within: thY(i6' or four-hours' after spraying i:it . will;, of-'conree;:'be ,to repeat the' yre3sihg;'as:soon. as' - possible.;. If'this,,treatihent: |,'is .carefully' darriedout' it; will :;pro've j effectual' in preventing attacks:., of Irish .....and:'..'early, and /WilUrreduce,'most':other'' fuigoiadiseases,; as Bordeaux- v 'the; germination .of -fungus,spores. , 'ItJ is. very/im-,,-portant'to spray 'all potato cro'ps, which do not ■appear, ; td>have contracted the disea.se,'in adis-. I trict '-where disease, is 'fpund. -, : Such .pjrayings be looked upon as an -insuraric?-'policy.' Jt prevents disease." r .' ~-; W.V■Men Who Succeeded. . ' ■\ Mr. Kirk- then'.'produced printed copies, of: letters from'.numerous New'..Zealand growers, 'showing; ; that, if thc.potatoes are', sprayed-when? the 'disease is- in- its earlier stages, the' opera-' .tibn f is.'-completely successful.' -' : ■ -There;. ;were severalJVletters similar ''to ' the;-following, one from Messrs.. Johns Bros., of Auckland ,r We' sprayed our crop in accordance ' with ! your, instructions,': and .-saved ii-t; We;',were; the bnlv ; persons in; : this neighbourhood who .sprayed, and . we ; are : the only- ones - who now. have -"a crop."-; Letters -received '-from Ireland arc to the same effect.-: Mr: 'A.; C.:Williains,' of Piitiki, ■Vyanganni,:', writes,:—"With |, tho:;exc©ption- ': ofthe -Hobart • Town' variety, 1 I have'.'saved :the whole crop,, andthey ..seom,. a !truly, splendid lot "of tubers. Everyono, else .at Putilci who failed to; spray,': orwho - only' ?praycd, once when the crop was badly' affected with blight,' had to face a: total loss" of their crops." The' headmaster; of. Matjiwhero--School,; Gisborne; wrote:—"Sprayed, according :to directions, and ours is.the:only crop in : the neighbourhood free from blight." : : ••': ■;; ' Some Practical Advice. } .-

' Asked --what tiro the -other remedial measures, | if', any; Mr. .Kirk said that some varie-' ties of. potatoes resisted the. disease more, than others. Seed potatoes 'should" lie .procured' •from clean districts, 'and should be stored'in a perfectly dry and well : vontilated shed. The dipping of'seed potatoes In-Bordeaux mixture,, using the i—l—4o. formula/ or, if the 6km is well : hardened, the G-4-10 >strength is' to' be .recommended, . if, done before -storing.- • ..This dipping 1 kills; only the spores and those'portions of -thei .fungus' that; are on the surfaco.-'of - ;the potato, lit it it is quit© 1 ineffectual in, destroying the .part which winters ;in the: tissues of the tuber itself should the' fungus have.'al-, ready obtained admission.- It is, therefore,' important tu. ; . sort over , the -tubers; from fime to time, and remote any showing the least sign of -rot". Wide' cultivation "is important; 'This enables; one';.to . cover,'the 'seed. with', a good, ■depth, of soil,",- and .Tenders' them . muchvless*' liable to .be [affected, even though the foliage may suifer severely.-;—'lt prevents , the', spores' of .the fungus being , carried down'-by'rain and other agencies',on' to .'the . tubers,' ;Only . manures known not, to l encourage the disaeso should -bo; used.; .Highly.-,; nitrogenous ;manures, 'such as.nitrate of soda,, blood, etc.,: help. the .contracting! of; disease, while, on'the other.'hand]' when - the;. ;manure used. is. : potash salts, -■ and phosphates, .the.-crop often-escapes, the .'disease to a ■- greatr'extent; '.- Good . drainage is 'another important ' point. The 1 disease is aided ' by moist': surroundings. ' The, addition of large quantities;- of ;lime. .to'.- the. .soil- .'will render crops grown on ever : moist soils less susceptible to -attack. _ The/disease .spreads 'on to healthy plants during the; 6ni»mcr only by means of spores,.' which are' blown about in immense •numbers from affected plants; and. can within an almostincredibly' short time; infect'' very large areas. A single .infected tuber planted iii a' crop can serve, as lan infection centre for, a whole district, so that .'it can easily, be seeii what, danger attends the planting of diseased sets.'.lf -.the' disease - existed - within■ tubers apparently eound in appearance, a layman could not detect it; but if: there were suspicious appearances about, any, of the tubers, ' planting should bo deferred until specimens had boon sont .to; the entomologist \fpr; his report. , , A Slender Hope. : Can you hold out any hope-of stamping out the blight in Tasmimia?—"That all; depends on how widespread'it is. ; "With the' practice of the, precautions I havo named, it. can be kept in check, .and ;if it is only to be found in a'; few/places, and- is ( not spread by seed, it may. be stamped out. 1 We shall; havo -to 6eo to what extent it exists in this State. I can-, not, of course,;answer your,question cither way until I have investigated." .' Mr. Kirk, in .the.(course--of his preliminary 'examinations 'of Tasmanian potatoes,, 'has diagnosed brown rust; (known in New Zealand' as "dry rot"), and- dry fleck (a constitutional disorder, not fungoid), as well 4s Irish blight.