172 " Damping off" etc., of Tomato Seedlings 



2. The organisms do not occur in all soils but exist as a definite 

 infection in some. 



3. Infection of the seedlings comes primarily from the soil and from 

 water. 



4. Seed-boxes and pots may carry on the infection from one season 

 to the next. 



5. High temperature and careless watering are frequently responsible 

 for the rapid spread of the disease. By sowing no thicker than fifty seeds 

 to the box, carefully regulating the watering, picking out diseased 

 seedlings, reducing the temperature as much as possible, and giving 

 sufficient ventilation, the disease may be reduced to a minimum. 



6. Soil sterilisation by heat or by formaldehyde completely frees 

 the soil from the disease organisms, and thus, provided the water is 

 non-infective, gives protection. In order to ensure a healthy crop of 

 seedlings, all seeds should therefore be sown and "potted up" in sterilised 

 soil. 



7. The application of a fine mixture of 10 parts of dry slaked lime 

 and 1 part of copper sulphate at the rate of f oz. to the square foot is 

 useful in reducing the amount of the disease. 



