SEVENTH ANNUAL YEAR BOOK— PART X. 633 



Chemical analysis showed about one-sixteenth more dry matter in 

 the sprayed potatoes and one-ninth more starch. Cooking tests con- 

 firmed the analyses, as the sprayed potatoes were noticeably more mealy 

 than those not sprayed, and were pronounced of much better quality 

 by all who ate both. 



The mixture recommended by the station is Bordeaux of the l-to-8 

 formula; that is, 6 pounds of copper sulphate to 50 gallons of water, 

 the acid of the sulphate being neutralized by about 4 pounds of good 

 stone lime. • • • Paris green may be safely added to thoroughly 

 neutralized Bordeaux (mixture and) this combination — Bordeaux and 

 an arsenical poison — has given better results in station tests than any 

 other fungicide-insecticide treatment for potato pests. * * * 



If thorough spraying is the object, it would be best to begin when 

 the plants are six or seven inches high and to spray every ten days or 

 two weeks as long as the plants remain green. If rain comes before 

 any application is dry on the vines the treatment should be repeated, 

 but spraying should not be stopped because "it looks like rain." 



(In the experiments reported) the number of applications ranged from 

 three to ten, and these were made with apparatus varying in power 

 and eflBciency all the way from a five-gallon compressed-air sprayer 

 carried by the operator to a power sprayer treating six rows at a time 

 and covering fifteen acres in a day. There was no fixed relation be- 

 tween make or type of sprayer and efficiency of protection. Some home- 

 made outfits gave excellent results. The essential feature is a good pump 

 or other source of power, so that a fine spray can be secured; all 

 other factors are incidental. * * * 



If only three applications are to be made during the season, delay 

 the first until it is necessary to treat the potatoes for the potato-beetle 

 "slugs" or shortly before the middle of July in central and western 

 New York. Then use the Bordeaux and arsenicals and spray thoroughly. 

 The second and third applications should also be thoroughly made 

 and at such times as will keep the vines as well coated as possible with 

 the Bordeaux. * * * It is not safe to depend on resisitant varieties 

 and neglect spraying. There is no good commercial variety, so far 

 known, that is "blight proof," and claims to that effect may be dis- 

 counted at once. Some varieties are more resistant than others, and 

 these should be selected, other things being equal, but even these should 

 be sprayed. 



In order to secure general spraying at the most economical rates, the 

 station suggests that growers arra'nge for a "public sprayer." That is, 

 let some one man in the neighborhood make a business of spraying and 

 secure enough fields to keep him busy throughout the season. This 

 plan combines several advantages: The farmer need not learn how to 

 epray; one outfit will do for a considerable area; the materials can be 

 bought in large quantities and therefore more economically; the pro- 

 fessional sprayer will become expert and do the work better and faster 

 than the grower himself; and the farmer will be relieved of all extra 

 work connected with spraying. In short, the public sprayer could spray 

 potatoes cheaper and easier than the farmer can do it himself and make 

 good wages at the same time. 



