DISEASES OF PLANTS. 



579 



factory remeily for the clul) root and that turnips do not thrive as a continuous (;rop 

 for many years. Experiments for the control of potato seal) have been continued, 

 but on a considerably reduced scale. The results thus far obtained have not been 

 uniform and while sulphur gave promise of value, before final judgment is rendered 

 the tests need to be carried on upon a number of different kinds of soil. 



The experiments with spraying were limited almost entirely to the use of soda- 

 I^.()rdeaux mixture with the same formula as that used in the previous report (E. S. 

 U., 13, p. 756). The tomato diseases were of so little consequence that but little 

 difference was noted in the sprayed and unsprayed plats. A leaf spot of chard due 

 to Ca-rospora heticohi developed to a considerable extent, and spraying with soda- 

 liordeaux reduced it to a considera))le degree. Plats of cucuml)ers, i-hard, and orna- 

 mental plants were sprayed with kerosene enudsion to test its value as a fungicide, 

 but the results obtained do not indicate that it has a value in checking the l)lights to 

 which these plants were subject. 



An experiment was carried on to determine whether Paris green could be used 

 with the soda-Bordeaux mixture, the fungicides being applied to potatoes, eggplants, 

 squashes, cucumbers, and beans. Each jilat was treated 3 times at intervals of 10 

 days without harmful results, althougli the Paris green was added in a much higher 

 penientage than is commonly emi>loyed. During the season covered by the report 

 observations were made on the asparagus rust and attempts were made to ascertain 

 its distribution throughout the United States. By means of letters sent to different 

 stations it was found that this disease extends from New England to the Dakotas and 

 south to Texas. As a rule there is an apparent decrease in the amount of asparagus 

 rust, which is attributed to the fungus parasites of the rust and the more extensive 

 cultivation of resistant varieties. Upon the college farm at the station the variety 

 Palmetto was found to be comparatively free from rust. The variety Argenteuil is 

 also quite resistant. It is claimed that the rust was more abundant on the west than 

 on the east side of the plats, and it is suggested that this was due to the quicker dry- 

 ing of the dew on the side toward the morning sun. 



The investigations on pear blight have been terminated on accomit of the change 

 in ownership of the orchards on which the spraying and pruning were being carried 

 on. The results for the different years' treatment are reviewed and summarized. 

 Brief notes are given on ergot on different species of grass, on corn smut and cucum- 

 ber blight, grape mildew, tulip mold, and fungi as related to weather. 



The occurrence of clover Broom rape is mentioned and the plant described. The 

 species present was Orohanshe minor. 0. ramosa was also found attacking a tomato 

 plant on the experiment station grounds. 



In continuation of the investigations described in the previous report (E. S. Pt., 13, 

 J). 757) a study was made on dimor]ihism of buckwheat, the third generation of the 

 plants seeming to show that there was a tendency for the pistillate form to exert 

 some control over the progeny. 



Plant diseases observed during 1901, E. Marchal {BuI. Aijr. [Bru.'<scl.-'], IS 

 {1902), No. 2, pp. 228-230). — Brief notes are given on the smut of cereals, potato 

 seal), bacterial rot of potatoes, fairy rings, cherry diseases, and pear blight. 



A report on cotton disease in Egypt, F. Fletcher {.Tour. Khediv. Ayr. Soc. and 

 School. Agr., 4 {1902), No. 3, pp. 122-126). — A preliminary report is given of a disease 

 of cotton which was called to the attention of the author in 1902. Upon visiting the 

 infected region he was informed that the disease had been nottced since 1898, and that 

 it made its appearance where Sea Island cotton seed from America had been planted. 

 The disease is believed to be of American origin, and reappears each year, the fungus 

 being capable of remaining in the soil from year to year. The symptoms are briefly 

 described, and various suggestions given for possible means of combating the dis- 

 ease. The author believes it is what is known in this country as sore shin, but the 

 rapid wilting of the plant seems to indicate that it differs from that disease as usually 

 described. 



