64 Report of State Board of Horticulture. 



the acid arsenates have some tendency to injure foliage and 

 that they cannot so well be used with the lime-sulphur Solu- 

 tions as can the neutral arsenates. While the available evi- 

 dence upon the above points is not sufficient to justify one 

 in condemning the acid arsenates, growers are advised to use 

 neutral arsenates wherever possible. 



Most manufacturers advise the use of three pounds of 

 arsenate of lead to 50 gallons of water. The Washington 

 Experiment Station has demonstrated that in the dry climate 

 of Eastern Washington one pound to 50 gallons gives equally 

 good results in Controlling codling moth. We have found 

 that two pounds are sufficient in the Willamette Valley. It 

 is quite probable that one pound may be sufficient here, but 

 since this has not been demonstrated we think it best to 

 advise two pounds to 50 gallons for the more humid portions 

 of this State. 



Some growers prefer to prepare the arsenate of lead as it 



is used. This is but little if any more troublesome than to 



mix the prepared arsenates in water and should be some- 



what cheaper. It can be readily prepared after the following 



formula : 



Arsenate of soda 4 ounces 



Acetate of lead 11 ounces 



Water 15 to 20 gallons 



Dissolve the arsenate of soda in two quarts and the acetate 

 of lead in four quarts of warm water. When dissolved add 

 them to the required amount of water. 



This formula is especially valuable for spraying very deli- 

 cate foliage or for use against insects which are killed only 

 by large amounts of poison, since it can be used UDon plants 

 in much stronger Solutions than the other food poisons with- 

 out injury to the foliage. 



If it is desired to use a combined insecticide and fungicide, 

 arsenate of lead may be added to Bordeaux or to lime-sulphur 

 Solution in the same Proportion as when water is used. 



BORDEAUX MIXTURE. 



Bordeaux mixture has been the urinciüal Dreventive of 

 funp-ous diseases. It is of some value as an insecticide, has 

 a beneficial effect uDon plants indeDendent of its effect uDon 

 their insect and fungous parasites and may be used for most 

 purposes in place of water in the preparation of the arsenical 

 sprays. 



Bordeaux for winter use may be made as follows : 



Copper sulphate 6 pounds 



Quick lime 6 pounds 



Water 50 gallons 



