DISEASES OF OHCHIDS, 09 



DISEASES or ORCHIDS. 



ARCHIDS arc subject to diseases in their leaves, stems, and pseudo- 

 ^ bulbs, especially during the damp months of winter. Of these the 

 most injurious are the Rot and the Spot. 



The Rot, which is apt to assail the thick fleshy bulbs, is caused by 

 too much moisture in the house, in many instances by water from 

 the syringe gathering in the sheaths surrounding the stems, and there 

 being a great want of circulation in the air. When the heat is low, the 

 drip from tlie glass will sometimes fall on the crowns of the pseudobulbs, 

 and this soon causes them to rot. Steam is also very injurious in a 

 house during the winter ; it is particularly inimical to such plants as 

 Cuttleyas, Laelias, Odontoijlossums, and other Orchids that have fleshy 

 bulbs. 



AVhen the leaves begin to rot, the diseased part should be cut clean 

 away, and a little sulphur rubbed on the part that is cut, but not so that 

 the sulphur can get to the roots. 



When the rot attacks the bulbs it should be seen to at once, as it 

 may easily be stopped by cutting the diseased part entirely away with a 

 sharp knife, no portion of the diseased or decayed bulb being left, and 

 ihe wound should then be filled up with sulphur, to keep it dry. Should 

 any part of the fleshy pseudobulbs of the above named plants, or of those 

 with similarly-formed bulbs, become discoloured, and the dark or dis- 

 coloured part appear moist or wet, especially if any fluid exudes from it 

 on pressure, the wet or discoloured part should be immediately cut out, 

 oi- there is danger that the bulb may be destroyed, as the rot is often 

 much more extensive within than the discolou^red appearances on the 

 outside would seem to indicate. The plant should also be removed to a 

 drier and cooler place, and water should be given with the utmost care. 

 The Spot is the dread of Orchid growers, and there is no denying 

 that when it attacks a plant it will soon disfigure it. Some assert that 

 it is infectious, but this we do not believe. Indeed, we should have no 

 hesitation in placing a plant infected with spot amongst a quantity of 

 healthy ones, and, should any of these become diseased, we should feel 

 certain it was induced by a wrong course of treatment in some respect, 

 and that no blame could be laid to the charge of the neighbouring plant. 

 A great deal has been said and written respecting this disease, which we 



