14 MASS. EXPERIMENT STATION BULLETIN 417 



Potato Seed Treatments. (C. V. Kightlinger and H. M. Yegian.) Experi- 

 mental work was done in 1943 to ascertain the comparative tolerance of potato 

 varieties to different disinfecting seed treatments and the effectiveness of these 

 treatments in controlling rhizoctoniose and scab. 



Several different seed treatments were used on Green Mountain, Irish Cobbler, 

 Chippewa, Katahdin, Earlaine, and Sebago potatoes which were slightly to 

 moderately infected with rhizoctoniose and slightly infected with scab. At the 

 time they were treated, the potatoes were either completely dormant or just 

 starting to sprout. The treatments used were mercuric chloride, mercuric 

 chloride plus acid, yellow oxide of mercury, Semesan Bel, Sanoseed, Spergon, 

 and Fermate, all of which were used carefully according to the directions. 



The inorganic mercury treatments injured the tubers of Chippewa, Katahdin, 

 Earlaine, and Sebago varieties, but not the tubers of Green Mountain and Irish 

 Cobbler varieties. The organic treatments caused no noticeable injury to the 

 tubers of any of the varieties. None of the treatments had any significant effect 

 on the stands of potatoes or the vigor of the plants, and no increase in yields was 

 obtained from the use of any of the organic treatments. Careful examination of 

 the growing plants and later examination of mature tubers at harvest time showed 

 little or no difference in the amount of rhizoctoniose and scab on the tubers grown 

 from treated and untreated seed. 



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

 Karol J. Kucinski.) Based on yields of marketable size, the ranking of potato 

 varieties grown in plots at the Experiment Station during the season of 1943 

 were Warba, Chippewa, Irish Cobbler, Sequoia, Sebago, Green Mountain, 

 Katahdin, Earlaine, Houma, S-46592, Mohawk, Russet Rural, and Pontiac. 



The ranking of the five common varieties of potatoes grown in plots, based 

 on 10-year average (1934-1943), was Green Mountain, Russet Rural, Chippewa, 

 Katahdin, and Irish Cobbler. 



DEPARTMENT OF ANIMAL HUSBANDRY 

 Victor A. Rice in Charge 



A Study of the Mineral Elements of Cow's Milk. (J. G. Archibald and C. H. 

 Parsons.) The work with zinc has been completed and the results published in 

 the April, 1944, number of the Journal of Dairy Science. Zinc oxide (10 grams per 

 cow daily) was fed as a supplement to the ration of eight cows for a period of 

 three months by the double reversal method. This consistently raised the level 

 of zinc in the milk, the average being 5.1 mgm. per liter of milk as contrasted 

 with an average of 3.9 mgm. when the cows were on a control ration. 



The same precedure was followed during the past winter in the studj' of the 

 element cobalt, which was fed as cobaltous acetate at the rate of one-half gram 

 daily per cow. Results are not yet available, as the analytical work is still in 

 progress. 



Investigation of the Merits of Legume and Grass Silage for Massachusetts 

 Agriculture. (J. G. Archibald and C. H. Parsons.) Practical aspects of this work 

 during the past year have involved a trial of the following as possible preserva- 

 tives: 



1. Urea (10 pounds per ton of green crop). 



2. Urea and molasses (urea 10 pounds, molasses 75 pounds, per ton of green 

 crop). 



