154 Diseases of Greenhouse Crops 



Rust 



Caused by Puccinia tnentha Pers. 



This disease attacks about thirty-five members of 

 the mint family. All the three stages of the fungus, 

 i.e., secidiospores, uredospores, and teleutospores, oc- 

 cur on the same host. The disease is characterized 

 by brown sori which are at first cinnamon colored and 

 later become chestnut brown. Diseased leaves curl 

 and dry up. The infected parts of plants should be 

 destroyed by fire. 



MusKMELON {Cucumis meld) 



Cultural Considerations. Muskmelon culture is 

 little different from that of the cucumber (fig. 29.). 

 However, the former is very sensitive to cold drafts 

 and sudden changes in temperatures. For forcing, 

 the heavier types of soil seem to be more desirable 

 than the lighter ones. The fertilizer requirements 

 for muskmelons are practically the same as those 

 for cucumbers. Muskmelons require an abundance 

 of soil moisture, but are sensitive to overwatering. 

 It is also essential to maintain a high hiimidity in 

 the house during the period of active growth. Dur- 

 ing pollination and the ripening of the fruit the 

 above condition is unnecessary. The temperature 

 should be about 70 to 75 degrees F. at night and 

 from 80 to 85 degrees Fahrenheit during the day. 

 Muskmelons, like cucumber blossoms, must be pol- 

 linated artificially, since both male and female flow- 



