256 
apple powdery mildew (.Podosjphwra oxyacantlice (DC) Winter?). 
Seedling apples sometimes suffer quite severely from this disease, 
which attacks their young shoot tips, often stunting the growth of the 
seedlings and preventing them from attaining a suitable size the first 
season. Compared with the injury caused by the apple tlirips, how¬ 
ever, that brought about by mildew is surely insignificant and, in New 
York State at least, hardly warrants any expensive measures for its 
prevention. The disease usually appears late in September, when the 
principal growth has been made, and seldom, if ever, spreads to vig¬ 
orously growing budded stocks, even when these are in close prox¬ 
imity to diseased seedlings. The malady was not observed on bearing 
trees in the neighborhood of Geneva. 
The experiments for the prevention of this disease comprised in 1891 
about 1,000 American stocks and the same number of Trench stocks, 
besides 500 seedlings. As stated in a previous publication,* the results 
of the first season’s treatment of the stocks was entirely negative and 
the treatments of seedlings which were made on May 21, June 3, 24, 
July 9, 24, and August 8 , as Are 11 as the early treatments made on the 
first three dates mentioned, failed entirely to prevent the appearance 
of mildew the first Aveek in September. Bordeaux mixture and am- 
moniacal solution alone were used, the formulae being those described 
on p. 202 . This failure of the fungicides is considered by the author 
merely as additional testimony to the fact observed that the mixtures 
Avere largely Avaslied oft' before the disease appeared. On August 7 the 
French and American stocks were budded Avitli Twenty Ounce, Fameuse 
and Early Strawberry buds, as described in detail on p. 259, and in the 
season of 1892 the budded, and such of the stocks as Avere left unbudded 
Avere treated Avith Bordeaux mixture and ammoniacal solution at dates 
the same as for all other stocks, viz, May 27 5 June 16, 23 j July 7, 21$ 
and August 5. One-half the treated stocks were sprayed 5 times on 
the first five dates mentioned, the other half Avere sprayed 6 times. 
No powdery mildeAv appeared during the course of the season, and in 
October the results of the treatments were entirely negative. The ap¬ 
ple thrips, however, attacked the budded and unbudded stocks and 
injured them severely. The mixtures had, as might be expected, no 
effect upon these insects. 
DETAILS OF THE EXPERIMENTS. 
The following pages comprise the details of the experiments, which 
are removed from the general account in order to render the latter more 
comprehensible. They Avill prove of interest only to specialists on the 
subject. 
*13ull. No. 3, loc. cit., p. GO. 
