Appendix. 143 



orchard should be at once resprayed. By a thorough study of the habits 

 of the moth in his locality one can learn to vary the length of the periods 

 between the different applications so that the fruit will be most thoroughly 

 coated. with poison at the times that egg laying is most active. Thus at 

 Corvallis, I have found that for the first brood this is i-etween June 20 to 

 25 and July 10 to 15, and for the second brood from about August 10 to 

 September 15. We shall, therefore, in the future, take particular pains to 

 keep the fruit thoroughly covered during these two periods. 



The methods of successful spraying are so well described in the two 

 articles in the appendix — one by Hon. E. L. Smith, a successful fruit 

 grower and president of the State Board of Horticulture, the other by Hon. 

 John D. Olwell, one of the most extensive and successful apple growers 

 in the state, and the first grower in the state to use a power spraying 

 outfit. Both of these men have had extensive experience with spraying 

 that pays and whatever advice they give can be safely followed in their 

 respective localities. It will be noted that Mr. Smith uses the arsenite of 

 lime,* prepared after a slightly modified Kedziet formula, while Mr. Olwell 

 uses a mixture of Paris green and London purple. I have principally used 

 Paris green. So far as efficiency is concerned it probably makes little or 

 no difference which of these poisons is used. The arsenite of lime is 

 cheaper than the other two and is more easily held in suspension. It is 

 extensively used at Hood River, and has given general satisfaction. Paris 

 green and London purple are too well known to require any further 

 notice than to say that the former is more uniform in the amount of 

 arsenious acid it contains than is the latter, and whenever the two have 

 been carefully tested side by side has invariably given better results. 



It will also be observed that both Mr. Smith and Mr. Olwell apply the 

 poison in a mixture of lime and water. In the Willamette valley and 

 along the coast, it should be applied in Bordeaux mixture for all sprayings 

 after the petals fall and previous to July 1. First, because the Bordeaux 

 is necessary to control the apple scab and other fungous diseases; second, 

 because it causes the poison to adhere to the fruit better than does any 

 other substance. After July 1, it is best to use the lime and poison only, 

 as the Bordeaux is not necessary and stains the fruit. To successfully 

 combat both apple scab and codling moth, it is advised to spray with plain 

 Bordeaux just a.s the leaf buds are unfolding, and again just as the blos- 

 soms begin to open. Within a week after the petals fall the trees should 

 be sprayed with Bordeaux to which one of the above poisons has been 

 added, the same amount of poison being used as when it is applied in 

 water. So far as codling moth is concerned, no other applications are 

 necessary in the Willamette valley until well toward the end of June when 



* Sometimes termed arsenite of soda. 



t First recommended by Dr. R. C. Kedzie, of the Michigan Agricultural Col- 

 lege. The arsenic and sal soda are boiled together until a clear solution of 

 arsenite of soda is formed. This is exceedingly injurious to foliage. It there- 

 fore must always be applied in lime water or in Bordeaux with an excess of 

 lime since the lime precipitates the arsenic as insoluble arsenite of lime, 

 thereby neutralizing its injurious action. In case the arsenic does not all be- 

 come precipitated injury to foliage may occur. 



