388 



preparing Bordeaux mixture is that of pouring a very dilute solution of 

 copper sulphate into a thick or strong lime solution. It is recommended 

 that no old Bordeaux mixture be used for spraying trees or plants. 

 This does not mean that old stock solutions of lime and copper sulphate 

 cannot be utilised, provided that the}' are properly kept and not mixed 

 until used. 



Watei hardness has no appreciable effect upon the precipitation of 

 Bordeaux or Bordeaux and lead arsenate mixtures, or on the sedi- 

 mentation of combined lime-sulphur and lead arsenate solutions. 

 It is advisable to avoid very muddy waters for preparing spray 

 mixtures. 



The amount of arsenic in solution in Borcieaux or lime-sulphur 

 spray mixtures when either acid or neutral lead arsenate is used is 

 small. 



Baerg (W. J.). Spraying for San Jose Scale. — ArkcDisas Agric. 

 Expt. Sta., Faydtcvillc, Bull. 177, November 1921, 19 pp., 

 2 plates. [Received 30th May 1922.] 



Tests in dormant spraying for San Jose scale [Aspidiotits periiiciosus] 

 with a number of substances were made during 1919-21, and the 

 results are recorded in detail. Lime-sulphur proved the most effective 

 material ; wherever this was applied, all scales were dead thirty days 

 after spraying. Scalecide gave the next best results, and has the 

 advantage of having no unpleasant effects on the human skin. No 

 injury to the trees was observed from it. Barium tetrasulphide is 

 now supplied in powder form, which is less troublesome than the 

 crystalline form. The combined effect of three years' use of this spray 

 is very satisfactory, but results over a shorter time are less successful 

 than with the above-mentioned materials. The dry materials, B.T.S., 

 dry lime-sulphur and soluble sulphur, though very effective in 1921, 

 were less satisfactory in the previous years, and are considered less 

 successful than lime-sulphur, though they have the advantage of being 

 easily transported over rough roads. Directions are given as to the 

 correct time for spraying and the suitable dosage of lime-sulphur 

 solution, which in the experiments recorded was 1 part to 8 of water. 



Cooper (J. R.). Commercial Grape Growing. — Arkansas Agric. 

 Expt. Sta., FaycttcviUc, Bull. 174, March 1922, 39 pp., 16 plates. 



Comparatively little damage is done to grapes in Arkansas by either 

 diseases or insects. Of the latter the following cause some trouble : 

 the gi"apc leaf -hopper [Typhlocyba conies'], the grape-berry moth [Poly- 

 chrosis viteana], the grape curculio [Coeliodes inaequalis], and the flea- 

 beetle [Haltica c/uilybea]. The usual measures against these are 

 mentioned. 



Hudson (H. 1 .). Field Crop Insects. Crop Rotation to offset Injury. 



— Canada Dept. Agric, Ottau-'a, Ent. Branch, Circ. 2, April 

 1922, 4 pp. 



A study has been made of suitable crop rotations for Canadian 

 fields in order to diminish as far as possible the injury caused by 

 white grubs [Lachnosterna], wireworms and cutw^omis. A suggested 

 rotation for a typical farming community of Western Ontario, where 

 these insects are present and no specialisation of any crop is in evidence, 



