502 Canker on Cucumbers. 



[We shall be most happy to receive this promised communi- 

 cation, as we consider the subject a very important one, and 

 one that appears at present (notwithstanding the attention it has 

 excited) to be very little understood.] 



Art. XII. On the Spot, or Canker, on Cucumbers. By John 

 WiGHTON, Gardener at Cossey Hall. 



This disease in cucumbers is occasioned by the beds being 

 cold and damp, as the following observations will prove : — When 

 the weather is sunny, and the beds warm, the plants will never 

 be found thus diseased ; but only when they become cold and 

 damp. I have taken diseased plants out of damp beds, and 

 placed them in a pit warmed by fire ; and the plants soon 

 returned to a healthy condition. Many gardeners consider 

 plants diseased in this manner to be liable to infect others : 

 this, however, is not the case; it is the bed, and not the plant, 

 which communicates the disease. This I have proved by ex- 

 periments ; having put healthy plants in the same bed with 

 those which were diseased, and found them speedily infected ; 

 whereas, when I had taken all the diseased plants out of a bed, 

 and replaced them with healthy plants, these also quickly showed 

 the disease. On the other hand, I have placed diseased plants 

 beside healthy ones in a warm bed, and the latter remained unin- 

 fected. The soil does not cause the disease ; for I have taken 

 soil in which diseased plants had grown, and placed in it other 

 plants : some of these I have put into a warm bed, and others 

 into a bed from which the soil came. The result has been, 

 that the plants in the cold damp bed soon showed the canker, 

 but not the others. Many suppose light soil to be the cause of 

 canker. This is so far true, as plants in light soil require more 

 frequent watering; and this, in time, chills the beds. Canker 

 follows, not, however, as a consequence of the soil, but of the cold. 



The canker has never appeared in my pits heated by fires, 

 except when 1 have given the plants much water, and when 

 this has been followed by dull weather. It has uniformly dis- 

 appeared after applying a little additional fire-heat. The real 

 cause of canker is, that the dampness and coldness of the beds 

 impede the growth of the plants, and cause them to break out 

 in spots. If the beds were warmer and had less moisture, the 

 tendency to ooze out and become diseased would go off with 

 the growth of the plants. The disease is commonly found in 

 low and damp situations ; and I have seen much more of it since 

 I have resided in Norfolk than I ever did before. With a view 

 to ascertain its true cause, the foregoing experiments were 

 made ; there being much difference of opinion on the subject 

 among gardeners. — Cossei/, Feb. lO. 1837. 



