18 MASS. EXPERIMENT STATION BULLETIN 347 



Testing Varieties of Corn for Grain and Silage. (W. G. Colby and Ralph W. 

 Donaldson.) A test of corn varieties begun in 1935 was continued in 1937. Yield 

 data of stover and shelled grain as well as information on time of maturity and 

 habit of growth were obtained on 125 corn varieties. These included Flint and 

 Dent varieties of local and regional importance and also a large number of the best 

 "hybrid" strains from the chief corn-producing sections of the country'. 



For use in the Connecticut Valley, the varieties tested can be divided into 

 three general groups: early grain, late grain and silage, and silage varieties. The 

 local Flint and Dent varieties together with varieties grown for grain in New 

 York, Michigan, Wisconsin, and Minnesota comprise the early grain group. 

 The grain varieties from Iowa, Illinois, Indiana, Ohio, Pennsylvania, and New 

 Jersey fall into the next or late grain and silage group. The third group is made up 

 of those very late-maturing varieties mostly from the Southern States which 

 mature little if any grain and can be considered only for use as silage. 



The best yields of grain and stover can be expected from the late grain and 

 silage varieties. In years of favorable growth and when the date of the first fall 

 freeze is average or later than average, most of these varieties will mature grain 

 in Amherst. Howevei , if the season's growing conditions are unfavorable for corn, 

 these varieties will not mature before frost and can only be used for silage. 



If a reliable grain-producing variety is wanted, an early-maturing strain must 

 be selected, which, although not yielding as will later-maturing strains, can be 

 depended upon to consistently reach maturity before the first fall freeze. 



Potato Variety Tests. (Ralph W. Donaldson, Walter S. Eisenmenger and 

 Karol J. Kucinski.) Yield tests of ten potato varieties were continued this year 

 on the experiment station farm. Each plot received six applications of Bordeaux 

 mixture, 5-5-50. One series of plots received gypsum (CaS04) at the rate of one 

 ton per acre, and the other series received the equivalent amount of calcium in 

 the form of ground limestone (CaCOg). Following are the yields per acre in 

 bushels. 



Gypsum Limestone 



Variety Treatment Treatment Average 



Green Mountain 382 407 395 



Chippewa 384 322 353 



Russet Rural 378 301 339 



Warba 287 251 269 



Katahdin 257 271 264 



Houma 261 — 261 



Irish Cobbler 284 216 250 



Bliss Triumph 235 263 249 



Golden 212 201 207 



"Idaho Baker" 189 202 195 



The Comparative Nutritive Effects of Copper, Zinc, Chromium, and Molyb- 

 denum. (H. Robert DeRose, Walter S. Eisenmenger, and Walter S. Ritchie.) 

 Tomatoes, buckwheat, and barley were again grown in crocks in pure white sand 

 which had been washed with aqua regia and then water and heated to 100° C. 

 Knop's solution was used, and the crocks were so regulated as to drain at the rate 

 of 1 liter in 24 hours. All salts used were recrystallized, and distilled water was 

 redistilled from Pyrex glass. Copper was used at the rate of 0, .05, .15, .50, 

 1.0, and 5.0 parts per million; and zinc at the rate of 0. .05, .15, .50, 1.0, 10.0, 

 and 20.0 p.p.m. 



Again it was clearly shown that both copper and zinc had a stimulating effect 

 on tomato plants when used in .05 and .15 p.p.m. concentrations. This was 



