500 Report of the Mycologist op the 



On the unsprayed plot the early blight was plentiful by June 

 25, and continued its ravages throughout the season. This plot 

 was less attacked than some other fields in the vicinity and more 

 than others; on the whole it was about an average field for the 

 season, as far as early blight is concerned. By August 2 Plot II 

 was badly affected with early blight, and there was considerable 

 on Plot III, but Plot I was almost perfect in foliage. On Aug. 

 15, not a single green leaf could be found on Plots II and III. 

 All of the plants were dead, while on Plot I about two-thirds of 

 the leaves were still green. The late blight did not appear at all. 



Throughout the season it was noticeable that the flea-bettle 

 injuries were much less numerous on the sprayed plots than on 

 the unsprayed plot. That Bordeaux mixture will check flea- 

 beetles is by no means a new idea. It has been repeatedly ob- 

 served by Prof. Jones at the Vermont Station and by others. 



Our experiment showed very strikingly, also, that Bordeaux 

 mixture is exceedingly distasteful to Colorado potato-beetles.* 

 At the time of the fifth spraying (Aug. 2) Colorado beetles were 

 quite numerous on the unsprayed plot, and on other unsprayed 

 portions of the field, while scarcely a beetle could be found 

 on Plot I and only a few on Plot III. This could not have been 

 the iconsequence of using Paris green in the Bordeaux mixture, 

 because no Paris green had been used since June 24, and since 

 that date several heavy rains had fallen, washing off all traces of 

 the spray applied at that time. In the case of Plot III, twenty- 

 four days had elapsed since it had been sprayed with anything. 

 Only traces of the Bordeaux mixture could be seen and yet the 

 Colorado beetles shunned the plants. Later in the season the same 

 thing was observed on tomato plants. Colorado beetles were un- 

 usually abundant, and when the potato plants died the beetles 

 migrated in swarms to egg-plants and tomatoes. Unsprayed to- 

 mato plants were almost completely stripped, while adjoining 

 plants sprayed with Bordeaux mixture were scarcely touched. 



At digging time the tubers on the three plots were sorted and 

 measured, with the following results: 



* Porjijiliura decemlineaia Say. • 



