444 EXPERIMENT STATION RECORD. 



a specific for tlie prevention of club root. A second crop of turnips 

 was sown on the ground after the removal of the first and the lime in 

 this case gave much better results than in the firstcrop. The suscepti- 

 bility of different varieties of turnips to club root was investigated to 

 some extent. Other things being equal, the variety which is most 

 superficial in its growth in the soil may be the least susceptible to club 

 root. A limited experiment with buckwheat on turnip land was 

 thought to indicate that buckwheat would exert a wholesome influence 

 on a soil that is "turnip sick" from the presence of the club-root fungus. 

 The effect of shading on the development of the club-root fungus was 

 tested, and it was found that the growth of the fungus was as active 

 in shaded as in exposed soils. Experiments were also conducted with 

 34 varieties of crucifers and 21 other plants representing 12 different 

 genera, and it was found that while there is a large group of wild and 

 cultivated crucifers that are susceptible to club root, many others are 

 only occasionally attacked and may be grown on badly infected soil 

 without being seriously injured. Of the plants representing other 

 genera than crucifers no indication of club root was detected in any 

 species. 



Experiments with cabbages (pp. 275, 276). — Cabbages were sown on 

 soil which had become so badly infected with club-root fungus that 

 turnips in 1890 were almost all diseased. The cabbage seed was sown 

 in a portion of this infected soil and at the time of setting out check 

 plants that had been started in limed soil were planted for comparison. 

 The details of the experiments are given, showing that the probable 

 time when the plants are most susceptible is when they are quite small, 

 and if this period can be passed free from exposure to the germs of the 

 disease the crop may be almost sure. 



Experiments with potatoes (pp. 27G-284). — For the past 4 years one 

 portion of the experiment station area has been devoted to the growth 

 of potatoes to investigate the means for the prevention of potato scab 

 (E. S. R., 9, p. 57). In 1S97 the experiments of the previous years were 

 modified somewhat. Oxalic acid, Bordeaux mixture, sulphur, kaiuit, 

 sulphuric acid, and corrosive sublimate were employed as fungicides, 

 and the effect of growing large- rooted weeds and sweet potatoes on the 

 development of the disease was tested. The yields of the different 

 plats are given, and so far as checking scab is concerned sulphur was 

 the most efficient. The season was particularly adapted to the develop- 

 ment of the potato rot due to Phi/tophthora infestans. The worst speci- 

 mens of this disease were found on the shaded portion of the plat, 

 although the plants in this area were somewhat later in being attacked. 



Experiments with peppers (pp. 284, 285). — In continuation of previous 

 experiments with peppers, 9 varieties were tested during 1897; and 

 while disease was almost entirely absent throughout the season the 

 experiment seems to indicate that in general pepper plants are too lit- 

 tle infested with fungi to warrant the application of fungicides. 



