432 Report of the Mycologist of the 



was smaller than in 1896, when it was about 20,000 per acre. In 

 some sections the crop was almost a total failure. In 1896 the 

 downy mildew was by far the principal enemy, but in 1897 it 

 seemed as if all of the enemies of the cucumber had combined 

 for its destruction. The weather was very unfavorable, and 

 downy mildew, anthracnose and the bacterial wilt disease wer§ 

 all destructive. Indeed, it was impossible to determine which of 

 these four causes was responsible for the most damage. 



Shade as a Preventive of Downy Mildew. 



♦ 

 It is a matter of common observation that down mildew is less 



destructive to cucumber plants which are partially shaded; for 



example, plants growing under trees or in weeds and particularly 



portions of vines which run out into the grass and tall weeds at 



the borders of the field. 



It was attempted to make a practical application of this fact 

 by planting rows of sweet corn alternately with rows of cucum- 

 bers. Rows of sweet corn were planted five feet apart, and when 

 the corn was a few inches high rows of cucumbers were planted 

 between the corn rows. On the same date other hills of cucum- 

 bers without the corn were planted close by for comparison. 



As might have been expected, the unshaded plants made con- 

 siderable better growth than the shaded. There seemed to be 

 no difference in the amount of anthracnose, only a slight differ- 

 ence in the amount of downy mildew, and the bacterial wilt dis- 

 ease was decidedly more destructive among the shaded plants. 



It seems improbable that shade can be advantageously em- 

 ployed as a preventive of down mildew. 



A New Host for Plasmopara cuhensis. 



The recorded hosts of Plasmopara cuhensis are as follows: 



(1) " On leaves of some cucurbitaceous plant "* (from Cuba) ; 



(2) Cucumis sativa L. (cucumber);! 



• Berkeley, Rev. M. J. and Curtis, Dr. M. A. Fungi C«beo»e«. Journ. of th« Llnnaeaa 

 Soc. Botany X, p. S63, 1869. 

 tFarlow, W. G. Not«s on Fungi. Bot. Ca«., XIV, ii. 1», Aug., 188J. 



