32 



THE REPORT OF THE 



No. 19 



Fig. 12. San Jose scale : an infested twig, scales and larv£e on bark — much enlarged. 

 ( After Howard and Marlatt. ) 



Prof. J. B. Smith, upon being called upon by tbe Chairman, said that 

 it was evident that the experience in dealing with the scale was in no two 

 places the same. In New Jersey it was found that the effect of spraying 

 with lime and sulphur was slow and cumulative; if properly done, no young 

 were produced, and the results were very satisfactory. In Georgia, in a large 

 orchard, containing over half a million trees, the lime and sulphur wash 

 was used without any salt and with a larger proportion of lime than usual; 

 the mixture, it was found, did not adhere so well to the trees. The next 

 time salt was added to the mixture, but not much difference was to be seen 

 in the results. The addition of salt made it spray more easily and spread 

 better. In Georgia and elsewhere many fruit-growers think that the appli- 

 cation of the lime and sulphur wash spoils the trees, and therefore they prefer 

 to use the oil treatment, either crude petroleum or kerosene. Pratt's Scale- 

 cide, a preparation of soluble petroleum, was found satisfactory. 



With lime and sulphur he found that the thinner the wash the better it 

 penetrated : he recommended boiling the mixture because by so doing good 

 results can be secured even with bad workmanship and inferior materials, 

 and using equal parts of lime and sulphur. This mixture was effective on 

 peach and plum trees, but was no good on apple and pear trees. An apple 

 orchard was treated with this wash, and in June the trees were still coated, 

 but they did not bear an apple worth marketing on account of the scales that 

 covered them. 



For apple and pear trees he recommended the oil treatment, using one 

 part of petroleum with twenty of water. Spraying should be done as early 

 as possible in the fall because many of the scales were still active and they 

 were not so closelv adherent to the trees as later on in the winter; the oil 

 could therefore get at them better and destroy the insects. This method was 

 very effective in keeping the scale in check, and we could not hope for ex- 

 termination. 



