62 MASS. EXPERIMENT STATION BULLETIN 347 



With 5-5-50 Bordeaux With 5-3-50 Bordeaux 



Material Yield Percentage Yield Percentage 



per Acre of Crop per Acre of Crop 



Bushels Grade 1 Grade 2 Bushels Grade 1 Grade 2 



Check 



(Bordeaux only) 261.7 75 11.5 257.5 67 18.5 



Calcium arsenate 396.6 83 8.6 270.8 77.5 10.5 



Derris (rotenone) 321.7 82.3 9.1 302.5 82.6 8 



Cubor (rotenone) 267.5 71.6 13.1 253.4 71.7 15.7 



Nicotine tannate 264.1 84.5 6.6 293.4 82.7 7.3 



DX (pyrethrum) 245.9 79.3 9.8 270.8 77.8 11 



All of the materials gave higher yields when combined with 5-5-50 Bordeaux 

 except nicotine tannate and DX. The yield in the plots of these last two materials 

 reflected the improved control of flea beetles which they furnished when com- 

 bined with 5-3-50 Bordeaux. 



Spray injury was very severe on the plots sprayed with 5-3-50 Bordeaux. 

 This undoubtedly explains the reduced yield. 



Two commercial brands of copper sprays for potatoes were compared with the 

 two strengths of Bordeaux mixture. Since many growers have expressed the belief 

 that lime alone would give sufficient protection against blight and insects, it was 

 applied to one plot. The comparative yield following these treatments is as 

 follows: 



Yield per Acre 

 Material Bushels 



Bordeaux 5-5-50 344.3 



Bordeaux 5-3-50 308.8 



Copper hydro (Chipman Chemical Co.) " . 306 . 6 



Basic copper sulfate -|-lime (Sherwin-Williams Co.). . 300. 7 



Lime alone 263 . 2 



When the potatoes were dug, nearly 1 percent of the crop in the lime plot 

 showed the presa»ce of rot. Sample hills examined earlier in the season showed 

 a much higher proportion of rotten tubers, which led to the belief that many 

 diseased tubers had completely disintegrated by time of digging and that the 

 difference in yield between this plot and the others would more accurately indicate 

 the actual loss due to disease. 



The comparative yield in the other plots follows very closely observations made 

 through the season on the relative amount of leaf burn. Considerable injury was 

 noted on the plants sprayed with 5-3-50 Bordeaux and the two commercial 

 sprays. The increased yield in the 5-5-50 Bordeaux plot reflected the superior 

 condition of those plants and their longer period of growth. 



Insecticides for the Control of European Corn Borer. (A. I. Bourne.) The 

 studies carried out in 1937 in cooperation with the Federal European Corn Borer 

 Laboratories, included field experiments in Hampden County with dual-fixed 

 nicotine, a newly developed nicotine tannate-bentonite dust, and continued tests 

 with derris and nicotine tannate sprays on two farms in Worcester County. 

 Both sprays and dust were applied as nearly at 5-day intervals as weather would 

 permit, beginning with the first appearance of the young borers in the field. In 

 every case the earliest maturing variety of sweet corn grown on the farm was 

 used in the tests. 



Between June 10 and July 5, the period during which applications were made, 

 rain fell on 13 out of the 26 days, and the total precipitation recorded was 4.1 

 inches. The season was decidedly unfavorable for both sprays and dusts. The 



