52 A ''Wither Tip' of Plnni Trees 



for in some cases it was seen that the stigmas were greyish after the 

 application. 



Four umbels were so treated, the central flower (which opens first) 

 and one or two others in each umbel being inoculated. The spurs bearing 

 these umbels were numbered and labelled, and notes were made respect- 

 ing the situation of the inoculated flowers in the umbels. 

 Umbel No. 1. Three flowers inoculated. 

 „ No. 2. Two 

 „ No. 3. Three „ „ 



No. 4. Two 



Thus in this experiment ten flowers were in all inoculated with the 

 " Wither Tip " strain of Monilia. 



In order to avoid an}^ inter-contamination between the two strains, 

 the particles of potato were replaced in the dish and taken back to the 

 laboratory. The needles were re-flamed and particles of a potato culture 

 of the "Blossom Wilt" strain of Monilia from apple trees were then pre- 

 pared and inoculations made on flowers on the opposite side of the same 

 tree. In this case only one flower of each of four umbels was inoculated. 



The inoculations were made on May 17 and the results as observed 

 at intervals of a few days are here shown for comparison : 



Apple Flowers inoculated May 17. 



"Witlier Tip" strain obtained from a '• Blossom Wilt " strain obtained from 



plum twig an apple tree 



May 20 



All the inoculated Howers had brown stig- ; All the inoeulatcd flowers had brown stig- 

 mas; some of the styles wei"c also dis- ! mas anfl the styles were brown for 1-.'} mm. 

 coloured for 1 mm. 



The rest of the flowers of the same umbels 

 and those of other umbels in the vicinity 

 showed no discoloration whatever 



Noother flowers on these branches showed 

 anv discoloration 



May 23 



The styles of the inoculated floweis were ) The styles of all the four inoculated flowers 



l)rown for from one-half to the whole of I were brown to the base. 



then- length. Uninoculated flowers on the same side of 



Most (jf the luitrealed flowers showed no dis- , the tree showed a slight discoloration of 



coloration at all; in a few cases a slight | the stigmas only 



browning of the stigmas was seen and 



one style was brown for about half its 



length 



May 2(5 



U»ihd No. 1. .Styles of all three inoculated ! No. I. Inocidated flower was brown with 



flowers brown to base; iu t woof the flowers ] eollapscil stamens, pedicel brown and 



the discoloration was also extending into shrunken (longituilinally sulcate), bases 



the ovary and the stamens were drooping of filaments with pustules of the fungus 

 or quite collapsed i 



