736 



EXPERIMENT STATION RECOED. 



potatoes. The results of experirueuts which he presents show that the abnor- 

 mal tubers produce only about 40 per cent of the yield of the normal tubers. 



The effect of defoliating' sugar beets, K. Andrlik and J. Urban (Ztschr. 

 Zuckerindiis. Bohnicii, SI (1907), Xo. 11, pp. 709-761). — A study of the develop- 

 ment of the sugar beet in its normal form and with part of its leaves removed 

 is reported. The rainfall from April 10 to October 3 was 375.3 mm. (about 

 14.8 in.), but its distribution was such that droughty conditions prevailed from 

 the latter part of June until August. 



Samples of 25 to 30 normally grown beets for analysis and observation were 

 taken June 21, July 5 and 31, August 21, and October 3. The weight of the root 

 in these beets increased irregularly, the smallest increase taking place in 

 August, and a much more marked development in September and October. The 

 leaf weight reached its maximum early in July, then declined during the dry 

 weather until August 31, and increased again in Sei)tember. The dry matter 

 ond sugar content in the beet increased until the end of July, when both began 

 to decline. The percentage of total nitrogen, which at first declined, increased 

 during the dry weather, but at the close of the vegetative period a decrease in 

 nitrogen had again taken place. The composition of the ash on the different 

 dates of sampling is given in the following table: 



Avvrtt<jc coiiiposilioii of (isli in ihr siKjdr Ixrt on iliffcrcnf dutcs ilnring the 



(jrowing period. 



The undesirable nitrogen compounds and the potash in the beet decreased 

 from June 21 to October 3, which was equivalent to an improvement in the 

 quality. It was further found that the maximum sugar content at the end of 

 July was not accompanied by the highest coefficient of purity. 



The weight of the dry matter increased regularly up to the end of July, but 

 from this time on to August 21 there was only a moderate increase until the 

 rains in September again accelerated growth. The increase in the weight of 

 the dry matter of the leaves during August was reduced by 21.0 per cent, 

 owing to the drying of the foliage, and the later renewal of growth did not 

 make up this loss. The average yield of dry matter per plant at harvesting 

 was 121 gm., of which the root furnished 74 per cent. The insufficient rainfall 

 during the summer retarded to a marked degree the formation of sugar and 

 dry matter, and also reduced the quantity of nitrogen taken up by the plant, 

 this being due largely to the withering of the foliage. The ash presented 

 variations similar to those of the nitrogen, and the fluctuations of each indi- 

 vidual constituent are shown and discussed. 



In studying the effect of defoliation 70 per cent of the leaves was removed 

 from the plants on one plat July 5, 94 per cent on a second plat July 31, and 

 10 per cent on a third plat August 21. The removal of 70 per cent of the 

 leaves reduced the yield of roots by 36 per cent, the yield of sugar by 35 per 

 cent, and the yield of dry matter by 34 per cent. The sugar content was only 



