6 HATCH EXPERIMENT STATION. [Jan. 



but very destructive in its effects. There was an abnormal 

 development, due to disturbance of the assimilative functions 

 of the plant. 



Remedies for the various diseases of lettuce grown under 

 glass have occupied the attention of the division of plant 

 pathology for several years. The " drop," which is charac- 

 terized by rotting of the stem and sudden and complete 

 collapse of the whole phmt, is the most destructive of these 

 diseases. The amount of loss is very commonly twenty-five 

 percent, of the entire crop. It has been found that by ster- 

 ilizing the soil, either wholly or in part, the drop and its 

 kindred disease can be wholly eradicated or suppressed. 

 Experiment shows that five-eighths inch or three-fourths inch 

 surface coverino; of sterilized sand or earth oave an averao^e 

 reduction of forty-seven per cent, in the amount of drop ; 

 one inch of sterilized sand or earth gave an average reduction 

 of eighty-seven per cent. ; one inch and a half of sterilized 

 soil, an average of ninety-three per cent. ; and two, three 

 and four inches secured entire immunity from the disease. 



In the entomological division the structure and life history 

 of various insect pests have been worked out and published, 

 and the remedies to be employed. Among those thus treated 

 are the grass thrips ; the thrips of the greenhouse, attacking 

 cucumbers ; the fall canker worm ; the marguerite fly ; and 

 greenhouse aleurodes, doing great damage to tomatoes and 

 cucumbers grown under glass. The San Jose scale continues 

 its ravages in the State. It has ah*eady been found in thirty- 

 seven different towns, and it probably exists in as many 

 more. It attacks the fruit as well as the bark, and speci- 

 mens of currants, pears and apples have been sent in so 

 completely covered with them as to render their sale im-: 

 possible. 



In the agricultural division the results of experiments 

 continued since 1890 with oats, rye, soy beans, clover and 

 potatoes seem to indicate that the various manures supplying 

 nitrogen rank in the following order : (a) nitrate of soda, 

 barnyard manure, sulfate of ammonia and dried blood ; (b) 

 that in crops of the clover family as nitrogen gathers, the 

 crops not being turned under, but improvement sought from 



