Studies on the Downy Mildew of Onions 



27 



TABLE 4. Effect of Suspension Medium on Spore Germination 



* The physiological salt solution was an 0.85-per-cent solution of sodium chloride in 

 distilled water. 



EFFECT OF TEMPERATURE ON THE TIME AND THE PERCENTAGE OF 

 GERMINATION OF THE CONIDIA 



After the above preliminary tests had been completed, germination 

 experiments were conducted at the following temperatures: 3°, 6°, 11°, 

 13°, 18°, 21°, 27°, 30°, and 35° C. The spores used in these tests were 

 prepared as described above. Six slides, each slide bearing three drops 

 of spore suspension, were used for each temperature. One slide for 



Figure 7. effect of temperature on the time and the percentage of germination 

 of conidia of peronospora destructor 



