4 EXPERIMENTS ON THE APPLE WITH SOME NEW FUNGICIDES. 



The matter became so serious that a special investigation was 

 started, and a series of field experiments was undertaken at Winches- 

 ter, Va., during the season of 1909 for the purpose of solving, if 

 possible, this russeting or spray-injury problem. These experiments 

 consisted in testing, by spraying, nine different fungicides. In the 

 test were included standard Bordeaux mixture, self -boiled lime- 

 sulphur, and various modifications of Bordeaux mixture. These 

 were the most promising fungicides known to the writer. Included 

 in the test were two new fungicides, a new form of copper sulphid 

 and a new iron sulphid, that were tested for the first time. To our 

 surprise these two new mixtures proved remarkably good and among 

 the best. The new iron sulphid, particularly, may have a promising 

 future. 



A full report on the experiments just mentioned, with illustrations 

 and with a discussion of the russet problem, is in preparation, but 

 as the interest in spraying and spray materials is so great and the full 

 report may not be ready in time for the spraying season, this pre- 

 liminary report is given out, particularly for the purpose of describing 

 the two new fungicides and the results obtained with them. 

 • Mr. F. V. Rand, Scientific Assistant, aided in carrying on the 

 spraying work and in taking notes of the results. 



PLAN OF THE EXPERIMENT. 

 SERIES I. 



The main experiment was carried out on the place of Mr. S. L. 

 Lupton, at Winchester, Va. The most complete series, containing 

 eleven plats, known as Series I, was on Mr. Lupton 's home farm. 



The following shows the formulas of the fungicides used on the 

 various plats : 



Plat 1. — Control, unsprayed. 



Plat 2. — Standard Bordeaux mixture (3-3-50). 



Plat 3. — Iron Bordeaux mixture (3-3-50 plus 2 pounds of copperas, or iron sulphate). 



Plat 4. — Standard Bordeaux mixture plus gypsum (3-3-50 plus 3 pounds of gypsum). 



Plat 5. — Neutral Bordeaux mixture (3-X-50, X equaling lime added until the 

 neutral point as shown by the litmus test is reached). 



Plat 6.— Self-boiled lime-sulphur (10-10-50). 



Plat 7. — Copper-sulphid mixture No. 1 (self-boiled lime-sulphur, 10-10-50, plus 

 2 pounds of copper sulphate). 



Plat 8. — Copper-sulphid mixture No. 2 (Bordeaux mixture, 3-3-50, plus 1 gallon 

 of commercial lime-sulphur solution). 



Plat 9. — Iron-sulphid mixture (self-boiled lime-sulphur, 10-10-50, plus 3 pounds 

 of copperas or iron sulphate). 



Plat 10. — Arsenate of lead (used alone), 2 pounds to 50 gallons. 



Plat 11. — Control, unsprayed. 



To each of these fungicides arsenate of lead in the form of the ordinary paste was 

 added at the rate of 2 pounds per 50 gallons of spray mixture. 

 [Cir. 58] 



