156 STATE BOARD OP AGRICULTURE. 



following estimate for the cost of spraying an acre of vineyard with 

 five applications of Bordeaux mixture is an average for medium-sized 

 vines : 



Labor, man and team, 6 hrs. @ 40 cents $2 40 



32 lbs. copper sulphate, @ 5 cents 1 60 



30 lbs. lime @ 1/2 cent 15 



Extra labor on trailers, and in preparing mixture, 



5 hrs. @ 15 cents 75 



Total 14 90 



In the above, no account is taken of the cost and depreciation of the 

 spraying rig, or of water-works and other conveniences required for 

 making the mixture. The cost would also be somewhat increased if it 

 became necessary to haul the water any distance, or if any serious break- 

 down or delay occurred in the work. On the other hand, when only two 

 or three applications are made, as might be sufficient in many cases, the 

 expense would be correspondingly lessened. 



In addition to the injury done by black-rot, serious losses also result 

 from the attack of downy mildew and anthracnose, while powdery mil- 

 dew is often quite injurious in hot, dry summers to varieties that are 

 in part of European origin. Aside from the loss which results from the 

 injury of these diseases to the fruit, even greater harm is done by them 

 to the foliage as it is not uncommon to see vines growing with a full 

 crop of fruit, which they are not able to ripen owing to the loss of their 

 leaves from the attack of milde.w. This can be entirely prevented by 

 giving the first two or three applications recommended for the black-rot. 



While the black-rot has not been generally troublesome except in the 

 Lawton district, it has made its appearance in quite a number of vine- 

 yards in other sections and has caused serious losses in various parts of 

 the state. For this reason, although we cannot recommend every one to 

 give his grapes the full number of applications suggested for the black- 

 rot, every grape grower who has noticed it upon his vines should be 

 prepared to spray and from the fact that there are very few vineyards 

 where mildew and destructive insects are not doing some harm, it is the 

 opinion of the writer that it will be only in exceptional cases where at 

 least two applications cannot be made Avith profit. 



For a number of years the use of dust sprays for the prevention of 

 diseases of the grape and other fruits has been strongly advocated by 

 manufacturers of dust spraying machinery. In 1907 and 1908 this was 

 given a thorough trial by several of the growers at Lawton and Paw Paw 

 but although it would have undoubtedly aided in controlling the 

 powdery mildew it seemed to have little efl'ect on downy mildew or black- 

 rot, as the injury from these diseases was practically as great as upon 

 neighboring, unsprayed vineyards. At a conservative estimate, fully 

 twenty-five per cent of the crop was destroyed by black-rot alone where 

 the dust spray was used, while with a smaller number of applications 

 with liquid spray it was reduced to a small fraction of one per cent. 



Similar claims have also been made for lime-sulphur solutions as 

 summer sprays but, although a thorough trial was made, little if any 

 benefit could be detected while, even when used at the strength of one 



