94 State Horticultural Society. 



The old rule, "An ounce of prevention is worth a pound of cure," 

 may be followed with profit in treating these diseases. Even after that 

 one must resort to spraying- to hold fungous diseases in check. 



It is now many years since the grape growers of France sprinkled 

 their vines with a solution of lime and blue vitriol by means of a whisk 

 broom. Since that time spraying and spraying machinery have been ma- 

 terially improved, and we know better w'hen to apply the sprays. Never- 

 theless, it may be well to consider a few essential points in the light of 

 what has been said concerning the habits and character of fungi. 



1. Why should zve spray? It has already been shown that the 

 proper time to kill parasitic fungi is at the time they germinate. The real 

 object of spraying is to prevent these spores from germinating and pro- 

 ducing germ tubes. If this can be done without injury to the host plant 

 fungous diseases will be prevented. 



2. Why should zvc spray ecurlyf The spores of many fungi rem.ain 

 uninjured on the tree or on the ground during the winter. As soon as 

 conditions become favorable for growth in the spring, they germinate and 

 infect the trees. 



The object of early spraying is to kill the spores, which are lodged 

 on the tree ready to germinate and infect the unfolding buds. 



3. Why is it necessary to spray several times? Because the first ap- 

 plication will be sooner or later, washed ofif by the rain. Moreover, all of 

 the leaves and blossoms do not come out simultaneously, and it is neces- 

 sary to cover them with the spraying mixture as well as the first-formed 

 ones. 



4. JVhy is it necessary to spray every year? Some disease-produc- 

 ing fungi live wholly or in part, on weeds and wild plants, from which 

 spores are carried each spring to orchard and vineyard. Unfortunately, 

 there are careless men who do nothing to hold fungi in check and allow 

 their plantations to become the sources of fungous diseases for several 

 miles around. It becomes necessary, therefore, to spray every year. 



It pays, moreover, to spray trees which have no fruit upon them, 

 because they will, if kept free from disease, set a greater number of fruit 

 buds for the next season than otherwise. 



5. Why does spraying sometimes fail to prevent disease? Some- 

 times the spraying mixture is not properly made. The preparation of 

 Bordeaux mixture sometimes gives trouble. Care should be taken to use 

 good lime which has been air-slacked. If there is too little lime used 

 there is danger of burning tender foliage. 



The follow'ing test is given to determine the correct amount of lime 

 in Bordeaux mixture. Dissolve i ounce of ferro-cyanide of potassium 



