8 GRAPE-SPKAYING EXPERIMENTS IN MICHIGAN IN 1909. 



negligible and there was no injury to the foliage. This was, how- 

 ever, not the case with some of the other mixtures. 



Neutral copper acetate used on plat 8 throughout the season burned 

 the leaves to some extent, while the foliage in plat 10, sprayed with 

 commercial lime-sulphur, Avas not in good condition. The ammoniacal 

 solution of copper carbonate and the self-boiled lime-sulphur did not 

 seem to brown the leaves, but the injury from rot was greater than 

 in the other sprayed plats. However, the amount of rot on all the 

 sprayed plats was so small that it is hardly possible to get more than 

 an indication of the comparative value of the different mixtures. 



THE EXPERIMENTS IN MR. TUTTLe's VINEYARD. NEAR PAW PAW, MICH. 



The experiments near Paw Paw, Mich., as has been said, were car- 

 ried on in a vineyard recently leased by Mr. Tuttle. It comprises 

 about 11 acres of Concord vines of good bearing age, together with 

 some mixed varieties. It had never been thoroughly sprayed and 

 had not received proper cultivation for several years. This was 

 not remarkable, for since 1906 the crop had been almost destroyed 

 each season by black-rot, and hardly enough fruit had been produced 

 to pay for the harvesting. The receipts from the crops for the 

 three years previous to 1909 were as follows: 



" Not known. 



The cost of harvesting for 1906 and 1907. which is not known, 

 would undoubtedly reduce the returns considerably. When the cost 

 of pruning, tying, and cultivation for 11 acres of vineyard is de- 

 ducted from the above returns it leaves a rather insignificant amount, 

 to say the least, as net profit. Counts were made in this vineyard in 

 1908 of good and rotten berries on a large number of average bunches- 

 and the rot was found to be 58 per cent of the total. 



The experiments in this vineyard were taken up to demonstrate 

 that the disease can be controlled by good cultivation and spraying 

 even after the black-rot lias become thoroughly established. The 

 vineyard was given careful and thorough cultivation by Mr. Tuttle. 

 Fourteen plats were laid out, thirteen of which were sprayed, each 

 plat being one-half acre in area except the check, which was three- 

 eighths of an acre. A geared traction sprayer was used, similar to 

 that of Mr. Giddings, with fixed nozzles for the first three applica- 

 [Cir. r.r.i 



