TEMPERATURE AND REPRODUCTION 



113 



[Dixon, McLean, and Wolf (1936)]. Mycelial growth, however, 

 may occur at temperatures either below or above this range. 



Sawyer (1929) found that a temperature of approximately 21° 

 C is most favorable for growth and reproduction by Entomoph- 



300 



g 200 



I 



■a 

 1 



Q 100 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



Aerated-^/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



-Non -aerated 



/ 



s 



/ 



/ 



/ 



/ 



s^ 



/ 



y 



5 10 



Time (days) 



15 



Fig. 8. Effect of aeration of liquid media on the dry weight of mycelial mat 

 produced by Verticillium albo-atriim. (After Chaudhuri.) 



thora sphaerosperma. Although growth occurs at 12° C, conidia 

 are not formed. 



Temperatures within the range 21° to 25° C were observed by 

 Longree (1939) to be optimum for sporulation of Sphaerotheca 

 pannosa var. rosae, but mycelial growth occurs well beyond both 

 of these limits. Crosier (1933) reported 21° C as optimum for 

 sporangial production by Phytophthora infestans. Krause (1930) 

 concluded that perithecial formation by Neocosmospora vasin- 

 fecta and Nectria coccinea is markedly influenced by temperature. 

 At 7° C Nectria coccinea requires 45 days to produce perithecia; 



