(/:> 



IRISH GARDENING 



their branclios instead ot spreadin- outwards soil level ; aritl on pullini,'' such a plant up the 



in a more or less horizontal direction lilt roots may remain in the i,'-round, the stalk 



upwards somewhat acutely. A closer exami- ha\in- been connected uilh them onlv bv a few 



nation shows that the leaves are trequently strands oi fibre which break awa\ on iMillins^. 



spotted, and that the smaller leaves curl When the attacked stalk is slil len-thwise it 



upwards and inward^ 

 alonii- the middle vein 

 or midrib. If the stalk 

 of sucli a plant be cut 

 across it will be found 

 to be quite toui^h to 

 the knife, contrastins^ 

 markedly with a similar 

 healthy stalk, which at 

 this season cuts \cr\ 

 easily. On the cut 

 surface 1 h e r e will 

 usually be IouulI three 

 brown spots at the 

 three corners, particu- 

 larly if the cut be 



made a few inches t.u- -vas, ,iia, .mu. 



above the "round level; whereas, a healthy attacked plants n 

 stalk, it cut across, shows no brown marks. because the plant is killed loui^" before it 

 These symptoms, however, either separatelv reaches maturity. When, however, a plant 

 or all toi^ether C^o not necessarily mean that is not attacked till tubers have been pro- 

 the plant is suffering- from Black Stalk-rot. duced. or when the attack, lhou!<h early. 

 The cruci.al test is that on pullini,-- the plant has not been so virulent as to prevent 



A I'l HI K wiiuii w\s Ar ru' iciAi.i.v In.ui 

 w nn I UK C'iKKvi oi Black .S i aM'^-ko 



i^lSF.ASE SPLIT l.ONtWTUOINAI.I.V. 



SlMwiii« tlie pmijress i>f tli-cay fmm llic ncf.llc -lal. am 



ulll be \oK\nd that the 

 I issues in the centre are 

 soft aiul pulpv lor ;i dis- 

 I ance ol sev eral inches 

 below. ;ini.l often .i 

 little above the j^rountl 

 level. In the further 

 course o{ the disease 

 the centre iM" the 

 stalk in this rei,''ion 

 becomes ciMiipletely 

 hollowed. 



Besides attackiui^ 

 the stalks, the new 

 tubers also are in- 

 vaded bv the disease. 

 In the e a r 1 i e s I 

 tubers are formed. 



The Stalk End of an affected Tiber 



OF POTATt^. 

 Showing the discolouied, (li>eased area. 



up by the roots the portion of the stem 

 below grround, and perhaps for some dis- 

 tance above the ground level, should be black 

 and rotting", [f the attack is an advanced one 

 the stalk may be rotted quite througdi at about 



Note. -"A Bacterial Disease of the Potato Plant in 

 Ireland." By Geo. H. Pethybridge and Paul A Murphy. 

 Proceedings of the Royal Irish Academv. 



.Vn attacked Tiber ci t Lengthwise. 



Showing the blackened, diseased tissues, with cavities in them 

 spreading from the heel end. A sprout is shown at " eye " end. 



their formation, such tubers are g-enerally 

 found to be diseased. Infection invariably 

 takes place throug-h the rhizome or under- 

 g-round stalk which connects tuber and 

 parent plant; and the progress of the rot in the 

 tuber may usually be g^aug-ed by the circle, 

 greater or smaller, according to circumstances, 

 of discoloured shin which covers the "heel." 



