Show SPRAYING POTATOES TO CONTROL BLIGHT experiments prove that bordeaux mixture Is effective results given of tests conducted last year in aroostook Aroos took county maine by the department of agriculture prepared by tho the united states department ot of agriculture that thorough spraying will control late blight in seasons of bad infection has been proven m many iny times in the past and most recently in tests conducted last year in aroostook Aroos took county maine by the united states department of agriculture in cooper co oper atlon with the maine agricultural experiment peri ment station some potato growers have expressed their opinion that it does not pay to spray potatoes tor for this disease Gro growers Ners of this opinion claim that when the weather conditions are suh such that the blight is severe spraying does docs not control it sufficiently to give an appreciable increase inthe yield and that in seasons when nhen tile attack is light the increase in the yield from spraying Is not sufficient to cover the added cost in one block where there small test plots sprayed with standard d ard bordeaux mixture were interspersed persed with untreated check plots the average yield on 11 of the former was at the rate of 1812 bushels per acre while that on an equal number ot of untreated plots was at the rate of 1435 bushels per acre this was au an increase ot of bushels per acre or more than 20 26 per cent in favor of bordeaux borde aus mixture in another similar illar block the average yield ot or five plots sprayed with bordeaux bord caux mixture was at the rate of nearly bushels per acre while that of the four untreated check plots in the lie same block was 1743 bushels the gala gain here was bushels per acre or about 30 per cent flue due to spraying six applications were made on fill all the abovementioned above mentioned sprayed plots 0 on these experimental plots spraying ought to have been started ten days or two weeks sooner or by tile end of tile first week in july in spite of tills this tact fact the yields given above indicate quite plainly that spraying paid moreover many persons who the plots plas during the latter part of the tenson teason have testified to tile the striking differences ul feren eren ces on sprayed and unsprayed portions on all the treated plots the spraying was done with a traction sprayer which maintained a good working pressure ot of at least pounds per der square inch adjoining one of the experimental blocks was a field where spraying was begun earlier and eight or nine applications were made it was planted with the same lot of the same variety of seed fertilized the same and ex cepe for spraying received similar treatment in every respect the yield on the portion of this field immediately adjoining one of the unsprayed check plots was 2673 bushels per acre comparing tills this with the averages of the unsprayed chock check plots mentioned above shows a gain of 1238 and 03 93 bushels bushel per acre respectively or over SO 86 and 53 per cents cent in none of the above figures is any account made of the extra loss resulting from tuber rot in storage in tile the crop produced on the unsprayed plots nineteen hundred and seventeen was one of the worst blight years in the history potato growing the results cited above show conclusively that even under the conditions that existed late blight can be controlled by a grower who sets out to do the job thoroughly moreover they indicate that it can be done at a fair profit when the cost Is considered in connection with the value of the increased yield resulting from the treatment these recommendations apply particularly ticul arly to the potato sections lying north of a line drawn from new york to chicago |