April, ’20] 
PARROTT AND OLMSTEAD: EMPOASCA MALI 
225 
abundant on the sprayed rows. Nevertheless, nymphs were observed 
on the vines, and during the latter part of August occasional burned 
tips were found on the sprayed plants, which was attributed to the 
unavoidable postponement of the fourth ^praying. The marked 
feature of the test was that the check plants showed during August 
burned tips and margins of the leaflets, while in early September they 
rapidly declined. At this time the sprayed vines presented in the 
main luxuriant foliage with only slight traces of injury; while the 
checks, in striking contrast to them, were inferior in size and had 
scanty foliage, which was to a large extent badly shriveled and brown¬ 
ish in appearance. It should also be noted that several experts in 
plant diseases, who had followed with interest the various develop¬ 
ments in this experiment, pronounced the injury to the checks as undis- 
tinguishable from the disease known as tip-burn. 
The heavy washes, composed of china clay or lime, were a little more 
effective in repelling the insects than the other spraying mixtures. 
These sprays, in spite of their heavy consistency, caused very little 
trouble in clogging the nozzles, and produced a thick coating of the 
foliage. However, some objectionable features developed which 
should be noted. The china clay was more easily removed from the 
foliage by rains than any of the other mixtures, in spite of the fact that 
it was combined with soap, while lime caused injuries to the foliage. 
The damage was first noted on July 29 when the third application was 
made, and after this date the injury considerably increased. Because 
of the serious damage, the heavy limewash was the least satisfactory 
of the various mixtures that were tested. Although the bordeaux 
mixture alone or in combination with lead did not prove as effective a 
repellent as the sprays of heavier consistency, it should be emphasized 
that thorough spraying of all surfaces of the leaves of potato plants 
prevented serious damage by leaf hoppers. Furthermore, this spray 
withstood the washing effects of the rains much better than china clay 
or lime, the combination with lead proving somewhat superior to 
bordeaux mixture alone. 
Mr. E. G. Kelly: In regard to Bordeaux-lime, do you make your 
Bordeaux and then add an excess of lime to it? 
Mr. P. J. Parrott: Yes. 
Mr. E. G. Kelly: What is the effect on the Bordeaux? 
Mr. P. J. Parrott: I am not able to answer your question, as we 
have not submitted samples of this combination to our chemists for 
analysis. In this particular planting we did not suffer from late 
blight, but I do not recommend the addition of large amounts of lime 
