ACnirirLTIRAI, AlMMUtPIUATtOV nil.I., I!l24. 201 



time, iukI that ilicv f>Miti n<> iii (cMtioii (<» tin- l»l. rii riist. Whon 



I jisk«'<l tlu'in wiml th«\v kiirw iiixtiil tin- hlark ^ "i»t thov «nul 



ihry (li«l not pay nny attention to it Hn«l «lul not o , it of tniijor 



iinj)ortanco at all. 



Mr. hfCMANAN. Ilnw al(uul the (iuMatu- foruiitioii> bnni; ihc 

 - \wr '. 



Doctor Stakman. 'Hie climatir rotulitions aro not 0!»<wntiallv «lif- 

 f«M«'nt from tlioso tlicrr: tlicy liav«« about th«' .same ron<lition.H hm wp 

 havo in the up[)«'r Missis<inf)i N'allry. 



in soutlu'ni (icrinaiiv I looked for rust for a Innj; tinn'. in Bavaria, 

 particularly. I>ut could not find any at all: ahsolutcly none. Tht\v 

 tolil inc at flicir cxjx'riincnt station I woulil not find anv and they 

 told nu' tlu' truth. They t«»ld inc that if I wanted to find rust I 

 ■should «;<> to the numntains. where there were a ;;reat many harlnTrv 

 htishos. and that if 1 went there I would he pra<'tically sure to find 

 ru-^t. I did find a <;r(>at man) harherry hushes anri everv place the 

 hushes existed tiiere were heavv attacks «)f rust. The situation wa.s 

 lust as clear as it possibly could ))e. In the rest of (iermany they have 

 oractically eradicated the harherry bushes, and the patholo(;i.st at 

 ihe imperial Biological Institute, where they do their plant-disease 

 work, told me that whenever there was a .^I'rious oulhreak of black 

 -tem rust they simply went to the |>articular farm or farms from which 

 it was reported and asked the owners where the barberry busiics 

 were. 



If the owners said there were no barberry bushes they simpiv asked 

 j)ermission to look ar(^)und ami they nearly always locateci the bar- 

 l)(»rrv bushes. Th(\v cited instance after instance in whieji that very 

 thin<; had hap[)ened. and that they could actually trace l)arberrv 

 bushes by the dev(>lopment of serious local out breaks of black-stem 



Ill ."swfMlen they now have a law for the eradication of barberry 

 buslu»s, but it has only been in force for a couple of years, and on 

 .ic<-ount of the miss;uided entiiusiasm of one or two people the lav. 

 is not particularly effective. They told me. and I saw with my own 

 I'ves. that there is a very definite and distinct relationsjiip l)etween 

 tln' «)ccurrcnce of l)lack-stem rust in Sweilen and th(» millions of bar- 

 berries aloni; the southeastern coast and up alon*; the east<Tn coast 

 of .Sweden. There are a great many barberry bushes in that refjion, 

 and it is th<'re that thev sufTer particularly from l)lack-stem rust. 

 In this country we think of the black-stem rust damajjinj; wheat. 

 Imt if anybody thinks that the black-stem rust attacks only wheat 

 ind oidy does damafje to wlieat he should see the situation in 

 .^wtMlen. becaus(> I saw oat fields there simply black with rust and 

 which were very seriously flaina'jcd. at the >ame time the yield 

 beino; very «jreatiy lessened. 



I saw rust over there on blue*.jrass and on varitms other gras.ses on 

 which we seldom find bla<k stem rust in this country. I have never 

 seen any rust on oats in this country tt) compare with the severity of 

 the rust in Sweden. In Sweden, over toward the mountains, there 

 are no barl)erries. and barberries will not tjrow l)«M-aus(> there is not as 

 much limestone in the soil over there as is ne<'essary for the {growth of 

 barberries. For years and years Swe<lish a^^riculturists and pathol- 

 ogists have gone to see if they couhl find any bhu'k stem rust in that 

 region, but they have always come back with the report of no black 



