II 14 STARCH CKOPS 



of malformed tubers relatively to the weight. The results of these deter- 

 minations are summed up in Table I, where in each group the varieties are 

 in decreasing order of the proportion of malformed tubers. 



The figures given in Table I and the other observations made on the 

 cultivations in question lead the writer to suppose that the capacity of 

 resistance to the formation of excrescences is a property of race, which 

 can be fixed by selection, and tests in other localities and on other 

 varieties would be highly desirable in view of the economic importance 

 of the potato. 



III. — Loss of Starch due to Excrescences. — The determination of the 

 percentage of starch by means of the Reimann balance showed marked dif- 

 ferences between the malformed tubers and those of regular shape. 



Table II sums up the particulars in reference to the industrial vari- 

 eties, the varieties being arranged in decreasing order of the losses of 

 starch sustained. 



Table II — Losses of Starcli due to Tuber excrescences in Industrial Varieties 



Varieties Loss of starch \'arieties Loss of starch 



"Devant le front" .... 4-3 % Brocken i-4 % 



Silesia 3.9 Grif 1.4 



Sas 2.8 Richter's Jubilee. . i.i 



Ever good 2.6 Prof. Wohltmann . 0.4 



Prince Bismarck 2.2 New Emperor ... 0.2 



863 - Comparison between the Effects of Manuring Potatoes with Nitrate of Soda and 



Sulphate of Ammonia (From the Agricultural Experiment Station of Radomysl, Russia). 



— Zasukhtn a., in XosHuemeo (The Farm), Xlth Year, No. 17-18, pp. 297-304. 



Kiev, ]VIay 191 6. 



Experiments carried out at the Agricultural Experiment Station of 

 Radomysl in sandy soil, i. e. poor in nitrogen, and for which nitrogenous 

 manure is of great importance. Two nitrogenous manures were studied: 

 nitrate of soda and sulphate of ammonia. The trials made with the 

 latter manure are particularly important because, owing to the present 

 war, the importation of nitrate of soda into Russia has greatly dimin- 

 ished, while large stocks of sulphate of ammonia have accumttlated, 

 and the extensive use of the latter in agriculture is imperative. 



In order to make this comparison between the effects of nitrate of soda 

 and those of sulphate of ammonia, the manure was used in two different 

 ways : sown directly on the tubers during planting or spread before this 

 operation. In addition, nitrogen was given to one plot, half in the form of 

 sulphate of ammonia before planting and the other half in the form of ni- 

 trate of soda during planting. The manure was put down in this latter way 

 in order to allow for the facts indicated in the literature of the subject as 

 to the itijury caused by sulphate of ammonia, as an acid salt, and as to 

 the retention of nitrate of soda by the soil. By applying the sulphate of 

 ammonia to the soil, before plantation, it was desired to combine the mo.st 

 favourable conditions for the utilisation of this manure, as the plant was 

 thus enabled to offer a better defence against its injurious action. By 



