174 



INJURIOUS INSECTS AND F'UNGl. [Sept. 1895. 



filaments upon them, hinder respiration, and make the leaves 

 and the whole plant unhealthy, causing deficiency in the crop. 



The complete history of this fungus has not been made out 

 clearly. It is supposed to be a stage of another fungus, just as 

 Oidium Tuckeri is the Oidiuw. or conidia-bearing form of a 

 fungus not at present defined. 



As a remedy for this fungus attack upon cucumbers, it was 

 recommended that powdered sulphur should be sprinkled upon 

 the infected leaves. This has been adopted and found to give 

 satisfactory results. Sulphate of copper and lime solutions were 

 also suggested. 



In frames, or houses, cucumber plants should be sulphured as 

 the heat and moisture will cause considerable volatilisation of 

 the sulphur. In the open air, there is but little volatilisation 

 of sulphur, and there is no concentration of the fumes. The 

 sulphur should be of the finest and lightest description, and 

 blown all over the leaves, and under them, with a soufflet, or 

 bellows, as figured below. 



A., tube with perforated end. B., stoppered inlet for powder. 



It is not necessary to put much sulphur on the leaves, and it 

 should be as fine as possible. 



For cucumbers grown in the open, a weak bouillie is better 

 than sulphur. The strength of this should be 10 lbs. of pure 

 sulphate of copper and 10 lbs. of pure lime to 100 gallons of 

 water, applied with a knapsack machine and a very fine jet. 

 This should be used, if possible, before the cucumber plants 

 blossom. If the fungus spreads rapidly, and it is necessary to 

 spray when the plants are in fl.ower, the action of the bouillie 

 upon them must must be carefully watched, and its strength 

 lessened if it chancres the colour of the flowers or burns them. 



Swedes affected by the mildew may be advantageously 

 spraj^ed by means of a horse-spraying machine, like that in use 

 for spraying potatoes. The bouillie in this case may be made 

 somewhat stronger, with from 1 2 to 1 5 lbs. of sulphate of copper, 

 and the same quantity of lime, to 100 gallons of water. It is 

 necessary to mix the sulphate of copper and the lime in separate 

 vessels, and to strain the lime-water before it is mixed with the 

 sulphate of copper. The colour of the bouillie should be cerulean 

 blue. 



