886 



Spraying Experiments. 



[FEB., 



the advice is given to use a wash of the specific gravity 

 roi to roi5 on apple and pear foliage— "the lower density 

 to be used if the grower is compelled to spray in unusually 

 wet and cold weather, or if much leaf-injury appears"; i'oj 

 for the foliage of the cherry; while for peach and plum foliage 

 thesp. gr. should be 1*003 to 1*008.* No information, appar- 

 ently, has been given as to the strength suitable for the 

 gooseberry. During the past season the following spraying 

 experiments were carried out with the object of obtain- 

 ing information on this point. A concentrated "home- 

 boiled " lime-sulphur wash f (prepared exactly as described 

 in this Journal for June last) was diluted with water to a 

 specific gravity of roi — this may be called the "full- 

 strength " wash; when injury to sprayed foliage appeared the 

 wash was further diluted to 1*005 — which may be called the 

 "half-strength" wash; further dilution was made when 

 necessary. 



Spraying Experiments on Apples. 



(1) During May several trees (having flower-buds on the 

 point of opening) of the following varieties growing in the 

 College plantations were thoroughly sprayed t with the wash 

 at "full-strength" (sp. gr. roi) : Cox's Orange Pippin, Bis- 

 marck, Worcester Pearmain, Duchess' Favourite, Belle de 

 Pontoise, and Golden Spire. No injury resulted to the 

 foliage of any variety. 



(2) On June 2nd single trees of the following varieties 

 (growing in a plantation at Selling, Kent) were thoroughly 

 sprayed in hot, sunny, close weather with the "full-strength" 

 wash : Beauty of Bath, Worcester Pearmain, Cox's Orange 

 Pippin, Allington Pippin, Charles Ross, Peasgood's Non- 

 such, and King of the Pippins. Somewhat severe "scorch- 

 ing" of the foliage resulted on Cox's Orange Pippin — about 

 a third of the leaves being more or less affected ; Charles 

 Ross was similarly injured, but not to so great an extent; 



* Pennsylvania State Coll. Agric. Exper. Station, Bulletin 92. 



+ A leaflet (price id. ) giving full instructions for the preparation of the wash can 

 be obtained on application to the Secretary, Wye College, Kent. 



X In all the experiments the spray was applied with a "Bordeaux nozzle" (see 

 this Joitmal for January, 1910) throwing a very fine, "misty" spray, by means of 

 which the surface of the leaves was thoroughly covered ; when dry, the leaves 

 appeared covered over uniformly with a whitish, dust-like powder. 



