836 EXPERIMENT STATION RECORD. [Vol. 38 



been determined. It appears doubtful that the size of the tubers is an im- 

 portant factor. 



Data obtained from the experiments with tubers in deep tanks to determine 

 how deeply potatoes may be piled with safety were deemed Insufficient for the 

 formulation of definite rules, but it appears that 6 ft. should be considered 

 the maximum depth of piling when potatoes are to be stored for several months 

 at temperatures below 45°, while at temperatures above 50° the depth limit 

 should be 3 ft. if the potatoes are to be stored longer than three or four 

 weeks. Tubers suffering from insufficient aeration through deep piling behaved 

 in general like tubers in .sealed jars, sprouting feebly or not at all, becoming 

 moist on the surface, discoloring externally upon exposure to the air, and often 

 being affected with black heart internally. The principal difference was in 

 the occurrence of rotten spots caused by fungi and bacteria. 



Black heart sometimes occurred in potatoes stored out-of-doors in pits, and 

 was due to insufficient aeration, although the experiments indicate that the 

 aeration of potatoes in unventilated pits is better than might be supposed and 

 that the ventilation of small pits is unnecessary. 



Injury resulting from insufficient aeration was due to the lack of oxygen rather 

 than to the accumulation of carbon dioxid. 



Tubers affected with black heart produced by exposure to high temperature 

 usually appeared normal externally, while those affected with black heart 

 produced by exclusion of the air usually showed more or less surface dis- 

 coloration. 



Insufficient aeration during storage did not cause spindling sprout, the tubers 

 upon being supplied with air sprouting normally if at all. 



Tubers severely affected with black heart are deemed unfit for seed purposes, 

 but slightly affected tubers may be planted. If tubers are sound and normal in 

 apparance, it is said to be unlikely that they have been injured for seed pur- 

 poses by any storage conditions to which they may have been subjected. 



The prevention of black heart is a shipping problem as well as a storage 

 problem, as the trouble often results from the overheating of potatoes during 

 shipment in stove-heated cars. 



Poor ventilation injures stored potatoes, F. H. Hall {New York State Sta. 

 Bui. ^36, popular ed. {1917), pp. 11, figs. 5). — A popular edition of the above. 



The agricultural situation for 1918. — VI, Rice. — Produce more rice for 

 consumption and export {U. S. Dept. Agr., Office Sec. Circ. 89 {1918), pp. 2Jh 

 figg_ 2), — The value of rice for human food is emphasized and increased con- 

 sumption in the United States urged. The production of rice in this country 

 attained a maximum of from 36,000,000 to 40,000,000 bu. during the last two 

 years, the consumption being about 90 per cent of the amount produced. Im- 

 ports declined approximately 40,000,000 lbs. during the last three years, while 

 exports increased about 139,000,000 lbs. for the same period. The largest 

 acreage was seeded to rice in this country in 1917 and amounted to 964,100 

 acres, while it is estimated that millions of acres are well adapted to growing 

 the crop. Aside from increased acreage, means for increasing the output of 

 rice suggested include better methods of irrigation ; proper seed bed prepara- 

 tion, seed selection, and method, rate, and time of seeding; the judicious use 

 of fertilizers; the proper drainage of land for harvesting the crop; careful 

 thrashing the eradication of weeds ; and the control of insects and diseases 

 affecting the crop. 



The agricultural situation for 1918. — III, Sugar. — More beet and cane 

 sugar should be produced {U. S. Dept. Agr., Office Sec. Circ. 86 {1918), pp. 

 34. figs. 2). — Stating that the world's annual shortage of sugar since the war 

 began has been more than 2,000,000 tons, the possibilities of increasing the 



