Annual Report of tee State Botanist. 7 



Squashes also have suffered unusually from a species of mold, 

 BJwpalomyces Cucicrhitarum, which invades the blossoms and 

 young fruit and induces rapid decay in the latter. 



The downy mildew of the grape, Peronospora viticola, has been 

 unusually virulent in its attacks . and remarkably luxuriant in its 

 development upon some varieties of the grape. Few species of 

 the cultivated fruits and vegetables of our gardens have wholly 

 escaped the ravages of their respective fungous parasites. 



The potato-rot fungus, Peronospora infestans, has been active in 

 both garden and field, and has not been at all behind other 

 species in its destructive energy. It was my purpose to make, in 

 my own garden, a thorough trial of the Bordeaux mixture as a 

 "preventive of this disease. But the fungus made its appearance 

 so much earlier than usual that the leaves were considerably 

 spotted by it before the first spraying was made and consequently 

 some spores were perfected and scattered before any treatment 

 was given. Notwithstanding this and the tendency of the fre- 

 quent rains to wash the mixture frpm the foliage, the plants 

 treated with two applications maintained a green and compara- 

 tively healthy foliage much longer than those that were not 

 sprayed. Wishing to see the result of planting diseased tubers, a 

 dozen hills of such were placed on one side of a small experi- 

 mental plat. By the side of this row three others of equal length 

 were planted with sound tubers. The plants from the diseased 

 tubers grew much more feebly than those from the sound tubers, 

 and the fungus first appeared on the lower leaves of this row. 

 It soon appeared on the adjoining rows but the discolored spots 

 were less in number the more remote the row was from the source 

 of infection. All the spotted leaves were then picked from the 

 vines to see if the progress of the disease might thereby be 

 checked. But it immediately appeared again and then the 

 whole plat wUs sprayed with the Bordeaux mixture. This gave 

 a very decided check to the progress of the disease. 11 days 

 later, which was July fifteenth, the spraying was repeated. 

 The foliage at this time was in excellent condition, look- 

 ing green and healthy. An absence of two weeks then inter- 

 vened. In the meantime heavy rains had fallen and washed 

 much of the mixture from the foliage, and on my return I found 

 the fungus had renewed the attack and made such headway that 

 it was useless to continue the experiment. But enough had been 



