BUREAU OF PLANT INDUSTRY. 283 



this office has urgently recommended the cutting down of the red 

 cedars in the immediate vicinity of the commercial apple orchards, 

 and after this year's experience many cedars are being" cut down. On 

 the other hand, the disease is apparently rather difficult to control by 

 spraying, but has been proved at least partly preventable. ISIany 

 striking examples have been observed this season in the increase of the 

 disease where the cedars are abundant near the orchard. 



Pear-blight eradication. — Pear-blight eradication work has been 

 continued in California on about the same scale as last year. The 

 disease appears to have been greatly reduced, especially in California 

 and southern Oregon. This is due parti}' to the work of assistants in 

 the field and partly to climatic conditions. The Rogue River valley, 

 where Mr. P. J. O'Gara, Assistant Pathologist, has been working, has 

 retained its fine pear orchards and stands as the best example of the 

 effect of thorough work in controlling this disease by eradication. 

 The results are due in large measure to the enthusiasm and thorough- 

 ness of tlie people in this valley and to the increased confidence in the 

 methods recommended by the Department. 



Pecan scab. — Work on pecan scab has been continued in South 

 Carolina. The results of the first year's spraying experiment, while 

 they showed that Bordeaux mixture could control the scab, did not 

 result in entirely satisfactory crops, for a number of reasons. This 

 work has been increased, new spraying experiments being under way 

 at one additional point in South Carolina and at one point in Georgia. 

 A series of fertilizer experiments on the pecan have been begun to 

 determine the effect of fertilizers in controlling pecan diseases. The 

 " drop " of pecans, by which the crop of nuts falls from the trees at 

 various stages, is under observation and study, particularly in the 

 fertilizer tests. 



Spray injury to apples. — The most striking thing that has taken 

 place in apple spraying since the introduction of Bordeaux mixture 

 for the control of apple diseases is the change from the copper to the 

 sulphur compounds that has been brought about largely through the 

 experiments of this office. The lime-sulphur solution is the leading 

 one in use, though the self-boiled lime-sulphur and the iron sulphid 

 are still under investigation. The spray russeting of the fruit by 

 copper poisoning and the foliage injury due to the same cause had 

 become so serious that considerable attention was devoted during the 

 seasons of 1900 and 1910 to testing various spray mixtures. Excep- 

 tionally beautiful fruit, in most cases free from fungous spots and 

 diseases, was obtained from the experimental plats. As a result, 

 orchardists have taken up the spraying with sulphur compounds as a 

 solution of this important difficulty. 



Some injury has occurred where the mixture was used too strong 

 or in cloudy weather. This was mostly on the tender foliage, and in 

 hardly any case was it serious. The lime-sulphur solution, being the 

 most convenient and satisfactory to use. has been accepted generally 

 by orchardists for spraying apples. "\Miere it has been combined with 

 the arsenate of lead generally excellent results have been obtained 

 with tlie combined spraj^; but in a few cases, undoubtedly owing to 

 insufficient agitation, there has been some slight burning of the fruit, 



