550 Bulletin 317 



pound less that year than for the mangels. In 1909 a drought in mid- 

 summer, accompanied by an attack of plant lice, made the crop almost a 

 failure and the cost of dry matter was very high. A moderately good 

 crop was secured in 19 10, but the mangels produced superior feed at less 

 cost of dry matter. Because of their sensitiveness to weather conditions, 

 the amount of soil necessarily harvested with them, and their limitations 

 in feeding to cows, no further experiments with rutabagas were made. 



The selection of mangel varieties for these experiments was made on 

 the basis of yields of dry matter in previous tests, and ease of obtaining 

 seed of these varieties from commercial seed houses. Two strains of the 

 Long Red, called " Norbiton Giant " and " Chirk Castle," were used dur- 

 ing the first two years. Both gave good yields of roots which were rich 

 in dry matter ; but because the seeds of the latter were much more expen- 

 sive than those of the former, only the Norbiton Giant strain of Long Red 

 mangel was used during the last two years of the experiments. A good 

 half-sugar variety of mangel was grown each year; in yields and compo- 

 sition there was little to choose between this variety and the Long Red. 

 The average yield and percentage of dry matter produced by these varieties 

 for three successive years was as follows : 



Percentage of 



dry matter 



Half-sugar mangel 17-93 1327 



Long Red mangel 17-75 ^3-3^ 



It was found that the half-sugar mangels pulled more easily at harv^est 

 time and carried less soil into storage than did the Long Red mangels. 

 Careful determinations in 1908, when conditions were most favorable for 

 harvesting mangels, showed that 5 per cent of the weight of Long Red 

 mangels, as deHvered at the root cellars, was soil. Of the half-sugar man- 

 gels 3 per cent of the weight was soil. In making comparative reports 

 of the yields each year, the above figures were used to obtain the net weight 

 of mangels produced. 



The most dependable variety of corn grown for silage on the university 

 farms is a yellow dent variety known as " Pride of the North." Other 

 varieties that produce a greater yield of dry matter were tried once or 

 more during the four years of experimenting. Some of these varieties were 

 too immature at harvest, or else could not mature Seed with certainty at 

 Ithaca, and for practical reasons will hardly displace Pride of the North 

 on the university farms. In 1908 the seed used was not home-gro^^^l and 

 the date of planting was late. Although some ears were ripening at 



