146 EXPERIMENT STATION RECORD. 



apple scab by the application of a spray before the flowers opened. On the plat 

 which was sprayed 3 times with a mixture of 1§ gal. of lime-sulphnr and 2 

 lbs. of arsenate of lead to 4Si gal. of water, 88.8 per cent of the apples were 

 perfect, 1.4 per cent scabby, and 9.6 per cent msseted, as compared with 50.7 

 per cent of perfect apples, 47.6 per cent scabby, and 1.5 per cent russeted on 

 the plat receiving only the last two applications of the same mixture. Similar 

 striking differences in spray efficiency are noted between the plat receiving the 

 3 applications and other plats receiving 2 applications, either of lime-sulphur or 

 Bordeaux. Although the authors do not contend that the later sprayings are 

 unnecessary, it appears that, under the existing weather conditions in 1912, 

 where the first spraying was omitted the profits derived from the 2 following 

 sprayings paid little more than the cost of application. 



A comparison of the plats which received only 2 applications shows that both 

 arsenate of lead used at the rate of 4 lbs. to 50 gal. of water and a 2:2:48 

 solution of lime-sulphnr-arsenate of lead was more efficient in checking scab 

 and gave a larger percentage of good apples than a 3 : 3 : 50 Bordeaux mixture 

 plus 2 lbs. of arsenate of lead. This was due primarily to the serious russeting 

 of the Bordeaux which amounted to about 35.3 per cent. No unsprayed check 

 plat was included in the experiment 



Both dry arsenate of lead and arsenite of zinc were tested as substitutes for 

 arsenate of lead paste for use in combination with lime-sulphur. So far as could 

 be observed none of these arsenicals produced any appreciable injury to the foli- 

 age. Their value as insecticides is not here compared but results from the 

 standpoint of spray injury led to the adoption of dry arsenate of lead, owing 

 to ease in mixing, in the spraying experiments for the following season. 



Lime-sulphur as a summer spray, J. B. S. Norton and T. B. Symons 

 (Maryland Sta. Bui. 16J,, pp. 263-272).— This bulletin points out the necessity 

 of summer spraying peach and apple trees to secure a good quality of fruit, 

 reports the results of cooperative work conducted during the past 2 years in 

 continuation of previous investigations (E. S. R., 23, p. 252), cites briefly some 

 of the worst diseases and insects attacking peach and apple fruits, and gives 

 recommendations for their control. 



The results of the spraying investigations as a whole led to the conclusions 

 that self-boiled lime-sulphur 8 : 8 : 50 is an excellent protection against peach 

 scab, and the best treatment for rot in view of the risk of injury from Bordeaux. 

 The self-boiled mixture, however, is scarcely effective against most apple dis- 

 eases. Sufficiently diluted concentrated lime-sulphur will control scab and rot 

 of peach to a great extent but with some danger of foliage injury. A stronger 

 dilution, say 1 : 40, is effective for most apple diseases except bitter rot but 

 with some danger of burning the leaf and fruit. It is not so good a fungicide 

 as Bordeaux but does not russet apples like the latter, Sulphocide used in 

 effective strengths usually causes marked injury to foliage. The results obtained 

 with atomic sulphur were too variable to be conclusive. -Although arsenate 

 of lead in the usual amount with lime-sulphur may cause some injury to peach 

 foliage, it is believed that this is the most effective combination for controlling 

 curculio. 



Spray and practice outline for fruit growers, 1913, H. J. Eustace and 

 R. H. Pettit (Michigan Sta. Spec. Bui 61, pp. 23, figs, ii).— This comprises 

 directions for the treatment of the important diseases and insects of orchard 

 and small fruits and potatoes, including instructions for preparing spray 

 mixtures. 



Fungicide and insecticide inspection (Maine Sta. Off. Insp. Jf7, pp. 13-20).— 

 This comprises a report on samples of various fungicides and insecticides in- 

 spected in 1912. 



