12 HATCH EXPERIMENT STATION. [Jan. 



limits. The principal sources of Botrytis infection are 

 inferior prickers or seedlings. All prickers showing the 

 black root should be discarded, as this is the beginning 

 of the Botrytis rot. No prickers showing any injuries to 

 the leaves, roots or cotyledons should be utilized, nor should 

 any dead leaves be allowed to form on the plants or be left 

 on them after transplanting. A strict adherence to the 

 above precautions will greatly reduce Botrytis rot. 



Another feature which should be considered in connectioa 

 with the Botrytis rot, as well as rots in general, is watering. 

 Lettuce growers have developed the tendency to do less 

 watering after the crop is set than formerly. They apply 

 most of the water previous to planting, at the present 

 time. This practice induces the plant to develop a better 

 root system. The surface of the soil becomes dry and 

 remains so, which constitutes a great feature in eliminat- 

 ing Botrytis rot, drop, etc. Were it possible for air and 

 sun to obtain access to a lettuce stem, there would scarcely 

 be known such a thing as lettuce rot, with the present skill 

 developed in handling this crop. Some growers have prac- 

 tised for some time the method of thorougrhlv wettinof the 

 soil before planting, and not applying any water after trans- 

 planting ; while others water occasionally for only two or 

 three weeks after transplanting. We demonstrated quite 

 early in our work the importance of keeping the surface of 

 the soil dry. Subirrigation methods reduce the rots to a 

 considerable extent ; and the method of thoroughly wetting 

 the soil previous to planting, and not supplying any water 

 afterwards, is similar in its effects to subirrigation, besides 

 having the advantage of being a much cheaper method. 

 Top coatings of clean, dry sand and other substances have 

 similar effects in reducino- rots. 



We believe that a great deal can be accomplished in 

 eliminating Botrytis rot and other diseases if more care be 

 taken in selecting seed of a more uniform size and character. 

 Care should be taken in selecting seed that will produce 

 more hardy plants, and that which will produce plants less 

 subject to infection. There is a chance for experimentation 

 and more careful study here. 



In one instance w^c have heard it implied that lettuce 



