58 BULLETIN 647, U. S. DEPARTMENT OF AGBICULTUEE. 



September 29. 1915. The treatment consisted solely of spraying, 

 cultivation, and tree .surgery. 



Spraying "was conducted against the chaff and purple scales, citrus 

 white fly. and rust mite, and for the destruction of the lichens and 

 moss which covered the trees (see PL II). The trees "were sprayed 

 only three times, the first application, for scales and the white fly, 

 being started February 12 : the second, for lichens and moss, May 12; 

 and the third, almost exclusively for scales and rust mite on the fruit, 

 on July 26. Two different brands of paraffin-base lubricating oil 

 made into emulsions containing 1 per cent of the oil and 0.5 per cent 

 of soap were used in the insecticidal work. A commercial lime- 

 sulphur preparation was used in the fungicidal work. 



The tree surgery consisted of pruning to improve the shape of the 

 trees, the removal of wood diseased with gummosis, and the cutting 

 back of Jaffa trees preparatory to rebudding. In some cases where 

 the trees branched from the ground into several trunks, those trunks 

 with poor tops which gave no promise of improvement were removed 

 entire. The pruning of smaller branches was very light and con- 

 sisted in the removal of all dead ones and thinning out of those 

 entangled. All wood infected with gummosis was gouged out 

 with a chisel and mallet and the wounds painted with a mixture of 

 1 part of creosote to 2 parts of coal tar. This work was all con- 

 ducted in the spring, from March to June. 



The demonstration plat was clean cultivated throughout the 

 season by plowing and cross-plowing, followed by disking both 

 ways of the orchard, four cultivations. March 8, May 12, June 21, 

 and August 26, respectively, being necessary. Close to the trees, 

 where the plow could not reach, the weeds were kept down by hoeing. 

 As the orchard had never before been cross-plowed, a good many 

 fairly large roots were broken in this work, but the trees did not 

 suffer any apparent ill effect from this rough treatment. The drain- 

 age ditches surrounding the plat were all deepened about a foot and 

 the weeds choking them removed. 



RESULTS OF ORCHARD TREATMENT. 



Within three weeks after the application of the lime-sulphur 

 solution most of the lichens with which the trunks and larger 

 branches were coated had fallen off completely, a solution of 30° 

 Baume, at 1 volume to 50 volumes of water, accomplishing this result. 



Owing to the thinness of the trees and scarcity of food in propor- 

 tion to the number of scales in this orchard, an exceptionally large 

 number of these insects settled on the fruit. A count of the chaff 

 and purple scales on 100 fruits from each of the two blocks on June 

 23 gave 112 on the sprayed fruits and 3,365 on the unsprayed, rep- 



