876 EXPERIMENT STATION KKCoKD. 



Treatment of certain plant diseases, V. I). Uiie,stkk {Delaware Sta. Bui. 63, pp. 

 ii'j-.i/). — A brii'f ri'piirt is givoii of exitcriincnt.s in Hpraying jjrapoH, treatinj^ aspara- 

 gus rust, and plum rot. 



The expi'riint'nts in sprayin<^ ^^rapt-s were conducted to test the effect of different 

 applications of Bordeaux mixture, and the relative value of Bordeaux mixture with 

 and without the addition of resin soap. The different rows of vines were given 1 to 

 4 sprayings of the different fungicides. Two sprayings gave nearly as good results 

 as 4 si)rayings and at half the cost. The yield was ai>proximately (loul)leil as the 

 result of the first 2 sprayings, and no special advantage wouM be gained by further 

 sprayings in the average seasons, but the persistence of warm, damp weather wcnild 

 justify a third application 2 weeks after the second. 



While the results did not show that the addition of the resin soap offercil any 

 advantage over the use of plain Bordeaux mixture, it is thought to make the spray 

 finer and cause a more even distribution of the fungicide. Certain plants, as aspara- 

 gus and plum, seem to reipiire the addition of soap to cause a proi)er s[)read of the 

 fungit'ide. On this account the author describes the method of preparing resin soaj), 

 which consists in heating 35 gal. of water and 42 l))s. of sal soda to the ijoiling point 

 in a water-tight Ijarrel by means of steam until the soda is dissolved, adding 60 lbs. 

 of melted resin, and continuing the boiling for an hour or two, until a homogeneous 

 mixture is obtained. Two quarts of this mixture are to be used with each barrel of 

 Bordeaux or other fungicide. AVhere steam is not available, the boiling may be 

 carried on in a kettle or boiler over a fire. 



An account is given of spraying experiments for the treatment of asparagus rust, 

 which demonstrate that the disease can be controlled by the use of Bordeaux-resin- 

 soap mixture. The first aj^plication should be made about the 1st of July and fol- 

 lowed by a second early in August. Ordinarily these 2 sprayings will carry the 

 plants over without injury to the next year's crop. 



In experiments in the treatment of plum rot the Bordeaux-resin-soap mixture w'as 

 tested with fairly satisfactory results. So long, however, as mummy fruits are allowed 

 to remain on the trees but little benefit will be derived from the spraying. The 

 author recommends the removal of all such sources of infection, and winter spraying 

 with strong copjjer-sulphate solution, followed by sprayings during the season as 

 recjuired. 



Some experiments with fungus diseases in 1903, L. F. Henderson {Idaho 

 Sta. ]hd. 39, pp. 267-272). — The 3 most serious diseases of fruits in the vicinity of 

 the Idaho Station are said to be the fire l)light of the pear, apple scab, and powdery 

 mildew of the gooseberry. During 1903 experiments Avere conducted to test the 

 efficiency of a gasoline spraying engine, the value of 2 sprayings of Bordeaux mixture 

 for the i)revention of apple scab, the efficiency of potassium sulphid in preventing 

 gooseberry mildew, and pruning for the fire blight of the pear. 



The gasoline engine was not found to be wholly satisfactory, due partly to the steep 

 hillside of the orchard, certain mechanical difficulties, and the cost of the machine. 

 Where the lan<l is not too steep and competent help is at hand for running the 

 engine, which is ke^itin good condition, the cost of the machine should not be con- 

 sidered as it is said to effect a great saving in manual labor, being more powerful and 

 rendering a finer spray, with less liability of the fungicide to clog the nozzle. It is 

 thought doubtful whether a gasoline spraying engine would prove a success in the 

 majority of the orchards in the Palouse country. 



Experiments for the prevention of gooseberry mildew were carried on with 3 or 4 

 applications of sodium sulphid of 2 strengths, 1 oz. and one-half oz. per gallon of 

 water. The results obtained show conclusively the efficiency of protecting fruit 

 against the mildew by this treatment, although the tips of some of the young shoots 

 at the end of the season showed the presence of the fungus. In order to stamp out 

 the disease the spraying should be continued late into the summer. 



