DISEASE AND ITS PREVENTION 79 



vines are not sprayed thoroughly the insects may gain foot- 

 hold and a portion of the crop be destroyed. 



In preparing the Bordeaux mixture, if a small amount 

 is to be made, have ready two half -barrel tubs, one for the 

 copper-sulphate solution, and the other for the lime solu- 

 tion. In one tub place five pounds of lime and slake with 

 sufficient water to thoroughly break up the lime without 

 allowing it to burn. After it has been thoroughly slaked, 

 add enough water to make five gallons of this solution. In 

 the other tub, put five gallons of water and suspend five 

 pounds of copper-sulphate in a gunny sack, so that two- 

 thirds of the copper-sulphate is in water and the other part 

 in air, as it requires air and water to dissolve. This should 

 be dissolved in about twelve hours. These are called the 

 stock solutions and will keep for some time if kept in a cool 

 place, but when they are mixed the spray should be used im- 

 mediately. When ready to spray, mix and pour enough wa- 

 ter into it to make fifty gallons in all. When strained and 

 mixed thoroughly it is ready for use. The solutions should 

 always be kept thoroughly stirred. 



The spray treatment is generally used for the blight, 

 yet when the Paris green is added it is equally effective for 

 the small insects, such as the black flea beetle and the 

 Empoasca Mali, a little green hopper. If blight and insect 

 pests are eliminated there will be less of the other diseases 

 because of the consequent healthy condition of the plants. 



When potatoes are blighted the larger portion of the 

 tubers are subject to a rot called "Jelly-End," and some- 

 times, when dug early, before it appears, they are generally 

 subject to "Dry Rot." As the blight is in the seed piece and 

 soil, it is wise to select good seed and spray to prevent the 

 appearance of the blight. Few people know or can appre- 

 ciate the injury done by the little black flea beetle. They at- 



