748 EXPERIMENT STATION RECORD. 



which are all leather hard in rind. Different liinds of manures applied did 

 not seem to iiffect the results. The juice obtained from all canes from which 

 the dry leaves were not stripped was slightly higher in sucrose content and 

 coefficient of purity than the juice from the stripped canes. Rose Bamboo has 

 proved a very promising cane. The results secured with this variety show that 

 by stripping 4,445.76 lbs. per aci'e of cane were gained but 229.GS lbs. of sugar 

 were lost. 



Sug-ar cane, A. de Medeibos (O Brasil: Suas Riqtiezas Natiiraes; i^uas Indus- 

 trial. Rio de Janeiro: Centra Indus. Brasil, 190S. Portuguese ed., vol. 2, pp. 

 10')-!7.'i). — The methods of culture practiced in Brazil and the general condi- 

 tion of the industry are descrilxMl. 



Acclimatization experiments with, sweet potatoes, L. Bernegan (Jahresber. 

 Ter. Aiujeir. Hot., .'> ( I'.xn ). /ip. !i()-!)!l). — The results of analyses of sweet 

 potato meal are given, and cultural tests with this crop in Germany are briefly 

 reported. The attempts at growing sweet iX)tatoes in Germany have thus far 

 not been very i)romising. 



Fertilizer experiments with tobacco, P. Wagner et al. (Arb. Deut. Lnndw. 

 GeseU., 1908, Xo. J38, pp. 99). — The results of cooperative fertilizer experi- 

 ments with tobacco are reported in detail and general conclusions are drawn. 



Plants grown with insufficient i»otash contained from 0.51 to 0.70 per cent 

 of i)otasli in the dry matter of the leaves, while this factor in plants overfed 

 with potash reached 10.15 per cent. The maximum yield showed a potash 

 content in the leaves of 2.3 per cent. It is stated that 7 per cent of potash in 

 the leaves is not to be regarded as extraordinarily high. In the average of all 

 experiments the fire-holding capacity of fermented tobacco leaves grown with- 

 out i)otash fertilization was 25 seconds, as compared with 4G seconds for those 

 having received potash. 



Analyses and tests of 19 different samples to determine the relation between 

 fire-holding capacity and ix)tash content showed an average of 0.9 per cent of 

 potash in the sample, with little variation for all samples tested. This potash 

 content is regarded as normal and sufficient to insure a good burn. The 

 average chloriu content of these 19 samples was 0.553 per cent, and it is con- 

 cluded that tobacco leaves should not contain more than 0.6 per cent of 

 chlorin. as a higher percentage interferes with the burning of the leaf. This 

 combination of potash and chlorin was apparently very good, for in all 19 

 samples the fire-holding capacity was so great that the leaves once ignited 

 burned completely. It is stated that as a rule heavy potash fertilization under 

 like conditions produces a tobacco of better burning quality than light potash 

 fertilization. It is pointed out, however, that the chlorin content of the leaf 

 must not be high if this result is to be obtained. It was observed that with 

 the use of fertilizers containing little chlorin the chlorin content of the leaf may 

 be reduced to 0.1 per cent, while on the other hand if fertilizers high in chlorin 

 are used the chlorin content of the leaf may reach 4 per cent. The conclusion is 

 drawn that for good burning qualities tobacco should contain from 5 to 6 per 

 cent of potash and not more than 0.0 per cent of chlorin. 



The potash requirement of the tobacco crop per hectare for a yield of 1.500 

 kg. of dry matter in the leaf, corresiionding to about 1,800 kg. of air-dried 

 leaves and stems, was found to be about 120 kg. (about lOO.S lbs. per acre). 

 To supply this amount it is recommended that 40.000 kg. of barnyard manure 

 and 100 kg. of potash in a readily available form be applied per hectare. 

 Without the barnyard manure an average of about 200 kg. of readily available 

 potash will supply this demand. The experiments show, however, that where 

 barnyard manure was ajiplied alone about the end of April the chlorin content 

 of the leaf was inci-eased and the burning quality reduced. It is advised to 



