H. AVORMALD Kill 



the tissues of the trees after the end of June of the year in which infection 

 occurs. This was found to obtain not only for the two varieties Warner's 

 King and Duchess' Favourite, but also for Lord Derby and James 

 Grieve of which there were a few trees with the disease in the same 

 plantation. 



On the cankers produced in 191.1 conidia were first ff)und earlv in 

 December of that year, and during January 1916 a consideiable number 

 of spurs and cankers showed pustules of conidia wliich jjroved to be 

 viable and able to germinate at the temperature of the open air. On 

 January 27 two hanging drops of distilled water containing conidia 

 from separate spurs were set up and placed outside in the open air. 

 Within 24 hours many of the conidia in both drops had germinated 

 and had produced germ tubes up to 32 fi in length. 



It was found necessary during the winter to remove the Duchess' 

 Favourite trees interplanted between the successive trees of Wai'ner's 

 King, so observations during the flowering season of 1916 were almost 

 confined to the latter variety; two Duchess' Favourite trees were 

 however retained and as the disease follow^ed the same general course 

 on these and on a few other trees of other varieties available for examina- 

 tion, the following account of the disease as it occurred on the Warner's 

 King variety may be taken as describing a typical outbreak of blossom 

 wilt. 



The withered trusses had been carefully cut off from ten trees at 

 one end of the row during the summer of 1915, while the rest of the 

 trees in the row were subjected to the usual pruning operations only 

 and many dead spurs and cankers, on which pustules of the fungus 

 subsequently appeared, were left on the trees. That there Avould be 

 another outbreak of the blossom wilt on these trees was expected there- 

 fore, and from the time the flowers began to open the trees were examined 

 frequently for the first signs of the wilt, in order that the earlier stages 

 of the disease could be recorded, as these had not been observed in 

 1915. 



On May 1 it was noticed that a few of the flowers on these trees were 

 open and the rest continued to open normally during the fortnight 

 following. Nothing unusual was observed until May 17 when one truss 

 was found to be withered and several others were showinji; the first si'Mis 

 of wilting as indicated by the flagging of the leaves at the base of each 

 affected truss. This wilting of the leaves is the first evident svmptom 

 of the disease, for the flowers may fail to "set" and so wither from other 

 causes. 



