198 RErORT OF THE BoTANIST OF THE 



August 0-11, 1900, the week preceding the occurrence of the 

 injury, was the hottest we:^k of the season. It was also very dry 

 and most of the time wiiidy. 



Later, the leaf scorch of pears was observed on a few trees 

 in each of several other orchards, and we are informed that it 

 occurred, also, on nursery trees of Kieffer at Dansville. 



Body Blight. — The so-called body blight of pear trunks which 

 is described on page 301 of Bulletin 167 of this Station is very 

 common throughout Western New York, By means of inocula- 

 tion experiments Paddock ^^ jj^j^ shown that this disease may be 

 produced by the apple canker and black rot fungus, ^phwropsis 

 malorum Pk. The same writer observed that the fungus Macro- 

 phoma malorum (Berk.) Berl. & Vogl. is also of common occur- 

 rence on the dead bark on pear trunks, and stated his suspicion 

 that it may play a part in the production of body blight.^^ How- 

 ever, his inoculation experiments with Macroplioma malorum, a 

 year later^ gave only negative results.^* 



According to our own observations both Sphwropsis malorum 

 and Macroplioma malorum occur abundantly on the trunks and 

 branches of pear trees affected with body blight. The Macro- 

 plioma certainly has the appearance of being parasitic and. Pad- 

 dock's inoculation experiments should be repeated before it is 

 finally decided that the fungus is not a parasite. 



In order to determine if Macroplioma malorum is an immature 

 stage of Sphwropsis malorum a pear branch thickly covered with 

 fruiting pycnidia of Macroplioma was kept under observation 

 from early May until September. The spores remained hyaline 

 to the end of the period, indicating that the Macroplioma is not 

 a stage of 8pli<^ropsis, but a distinct species. This conclusion 

 is in harmony with Paddock's observations on Macroplioma 

 malorum^^ in cultures. 



'= Paddock, Wendell. The New York Apple-tree Canker. Bui. 1G3 of 

 this Station, pp. 184, 203. 

 ='L. c. 



='Bul. 185 of this Station, p. 212. 

 =»L. c. 



