Treatment of Sick Soils 47 



Table 4 



Flat NuriibcT 



Weight of Seed Sown 



Plants 

 Diseased 



Per 

 Flat 



Per 100 

 Square Feet 





Grams 

 0. 1 

 0.2 



0.3 

 0.4 



0.5 

 0.6 

 0.7 

 0.8 

 0.9 



1.0 



Ounces 

 0. 16 



0.33 

 0.49 

 0.66 

 0.83 

 0.99 

 1. 16 

 1-33 

 1.49 

 1.60 



Per Cent. 



0 



0 



8 

 15 

 35 

 75 

 80 

 80 

 92 

 96 



2 



3 



4 



5 



6 



7 



8 



9 







Certain soils are especially favorable to damping 

 off. Soils which contain a higher percentage of 

 unrotted vegetable matter, and those which are hard 

 to drain need special attention. Great care should 

 be taken to keep the seed bed at the right tempera- 

 ture. The latter cannot be guessed at by personal 

 sensation. It should be accurately determined by 

 thermometers placed in the bed at suitable distances. 

 It should also be remembered that any covering 

 cloth or sash will exclude light and air. Every 

 precaution should, therefore, be taken to prevent 

 the seedlings from becoming "drawn," for in that 

 condition they are most susceptible to damping off. 

 The safest plan is to keep the temperature a trifle 

 lower than is generally required, and to allow as 

 much ventilation as possible. Very often damping 

 off starts only in one corner of the bed. To check 

 the rapid spread of the disease, the infected area 



