352 
HORSE-OJJESTNUT LEAF-BLIGHT ." 5 
Horse-chestnut seedlings are subject to leaf-blight to such an extent 
that it has come to be looked upon by many nurserymen as something 
entirely normal to their growth—a natural ripening of the foliage. The 
disease first makes its appearance toward the latter part of June, and 
before the middle of August the leaves are generally entirely dead, 
often remaining attached to the seedlings until the middle of October 
or later. Although the damage done to the foliage of fully grown 
trees is not as serious in this northern climate as it is in the neighbor¬ 
hood of Washington, 1). 0., the young trees of two or three years’ growth 
often have their foliage materially injured by the parasite. The prin¬ 
cipal growth of the horse chestnut being made very early, i. e., in the 
first six weeks, it is doubtful whether the loss to the plant is as great 
as in plants with a longer period of growth. The reserve material 
stored up must, however, be much less in defoliated stocks than in 
those maintaining healthy foliage throughout the season. 
The experiments in the prevention of horse-chestnut leaf-blight were 
inaugurated in 1892, and only a preliminary report as to the effects of 
the fungicides is possible. 
Two rows, comprising in all over one thousand seedlings, were under 
treatment. The seed was gathered from trees growing on the station 
grounds and planted in the fall of 1891 in shallow trenches. Nearly 
every seed germinated and an excellent u stand” was secured. 
One row was divided into twenty-four sections, each containing twenty- 
five or more seedlings, and treated with the same mixtures as those 
described previously as being used on pear seedlings. Preparations 
Nos. 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, and 25 were used. Only 
alternate sections were treated, the intervening sections serving as con¬ 
trols. The dates of treatment were June 22, July 0 and 20, and Au¬ 
gust 1 and 15. At these dates the foliage of each section was thoroughly 
wetted with the preparation. 
The disease first made its appearance the last week in June and 
spread very slowly over the experimental rows, injuring the foliage 
very irregularly. The sections, with two exceptions, seemed to be 
little benefited by the treatments. Preparations 14, 17, 18, 19, 21, 22, 
24, and 25 injured the foliage to a greater or less degree. The injury 
manifested itself generally by a sickly yellow or brownish coloration 
of the foliage. On October 14 the only two preparations whose good 
effects were visible were Nos. 13 and 25. When everv stock in these 
ty 
*Phyllosticta sphwrojjsoidea E. &. E, 
