THE CANADIAN IIOKTICULTURIST. 163 



THE ROT m TOMATOES. 



Our thanks are due to Mr. W. E. Wellington, of the firm of Morris 

 Stone & "Wellington, for a copy of the Gardeners' Chronicle, Nov, 12th 

 1881, from which we copy the following paper on the Fungoid Diseases 

 of the Tomato, by Charles D. Plowright, King's Lynn, England. This 

 paper will probably fully answer the inquiry of Mr. Thomas Coates, 

 in the November number : 



Puring the autunm of last year (1880) I carried on a series of investi" 

 gations concerning the various fungi which deleteriously aftect the Tomatoi 

 having the oi>portunity of examining any and every di.sea.sed specimen of 

 Tomato which occurred in a large Tomato growing establishment near 

 King's Lynn. 



Tomatos grown in the open air in this country are a very uncertain 

 crop, sometimes proving a very profitable venture, but not unfrequentlv 

 the reverse. The Tomato disease i.s almost as well known to gardeners, 

 and as much dreaded by them, as the Potato disease is. A very large 

 number of outtloor diseased Tomatos were examined by nie last year. The 

 appearance of diseased Tomatos is so well known that it is almost unneces- 

 sary to give any description of it beyond stg>ting that they have a peculiar 

 bruised look, and are more or less mottled with black or dark browii 

 patches of disease. These patches increase in .size after the fruit has been 

 gathered to such an extent as to render it valueless. If the Tomato be 

 examined in this state he must indeed be an acute mycologist who could 

 demonstrate the fungus which has caused the disease, for, hearing a few 

 hyaline mycelial tubes permeating the substance of the fruit in and towai'ds 

 the margins of the spots, nothing adventitious can be detected. At any 

 rate, I was quite unable to find any perfect fungus upon the numerous 

 speeimens I then examined which could with certaiaty be credited with 

 causing the mischief. This is not to be wondered at when it is remem- 

 bered how rarely we are able to discover the perfect Peronospora infestans 

 upon the diseased tubers of the Potato. On September 10 of this year a 

 specimen of a typically diseased Tomato was brought to me with the infor- 

 mation that although the Tomato was diseased the plant which had 

 produced it was healthy. I at once visited tho spot and examined the 

 ])lant in (juestion. Sure enough the Tomatos on it were diseased to a largo 

 extent, but the plant looked healthy. A few dead-looking .spots were 

 observed upon the lower leaves, which were examined with a pocket lens, 

 but not very thoroughly, as it was raining at the time. When, however, 

 these dead-looking spots were exaniined microscopically, they were found 

 to be due to the presence of Peronospora infestans. The fungus was not 

 j)roducing its conidiiphores very abundantly, but still there it was without 

 <loubt. The central portion of the spots where the Peronospoi-a first made 

 its appearance were now nearly free from it, it being more or less confined 

 to tho circumferential portions of the spots. The appearance of these spots 

 was quite unlike the spots produced by the same fungus upon the Potato 



