58 Maine; agricultural experiment station. 1913. 



Station for the first time in its history an opportunity to make 

 spraying experiments on a large scale in an orchard entirely 

 under its control. By this time the results of experiments made 

 in other parts of the country indicated that a concentrated mix- 

 ture of lime and sulphur in water, cooked by artificial heat and 

 then diluted before applying, was the most promising lime-sul- 

 phur spray for apple orchards. It was claimed to be more ef- 

 fective than the self-boiled article and entirely free from spray 

 injury, thus, in this respect, being much superior to bordeaux 

 mixture. 



Therefore an experiment was planned for 1910 as one of the 

 plant pathology projects for that year in which it was proposed 

 to test the value of artificially boiled or cooked lime-sulphur. as 

 an orchard spray, as compared with the self-boiled and with 

 bordeaux mixture. Also it was planned to test the relative 

 efficiency of several commercial brands of concentrated, boiled 

 lime-sulphur as compared with the home-cooked article. With 

 the appointment of Mr. \A'. W. Bonus as Station Horticultural- 

 ist, stationed at Highmoor Farm, the project was transferred to 

 his department. Mr. Bonus carried on two series of experi- 

 ments, one in 1910 and one in 191 1, the results of which were 

 quite full}^ reported in Bulletins 189 and 198. In the first publi- 

 cation, in addition to giving an account of the results of the 

 experimental work of the season, he reviewed in considerable 

 detail the literature upon the use of lime-sulphur as a summer 

 spray, the use of sulphur and its compounds as fungicides, the 

 question of spray injury from bordeaux mixture, etc. On 

 account of the great demand for Bulletin 189 it was soon out of 

 print. Therefore a summary of the experimental results ob- 

 tained in 1910 were included in Bulletin 198 with those obtained 

 in 1911. 



The apple orchards at Highmoor Farm consist almost entirely 

 of the Ben Davis and Baldwin varieties. The entire orchards 

 were sprayed once late in June 1909 with bordeaux mixture and 

 arsenate of lead, largely to control leaf-eating insects, just as 

 soon as it was found that the purchasing committee had decided 

 to buy this farm. So far as known this was the first time the 

 trees, which were then in a much neglected, half-starved condi- 

 tion, had ever been sprayed. In 1910 all but the experimental 

 plots received three applications of bordeaux mixture and arse- 



