FIELD CROPS. 845 



the procesis of drying tobacco, and determined some of the conditions that influence 

 the quahty of the dried leaf. Three stages in the drying process are distinguished: 

 The first stage from tiie time the tobacco is hung until the cells of the leaf blade are 

 dead; the second until the leaf blade is dry, covering about two days; and the third 

 stage is characterized by the death and drying of the midrib. At its close the leaves 

 are taken down and i-arried to tlie fermenting barn. 



Be.'"ore the death <if the cells the i)assage of the cell contents is controlled by the 

 living protoplasm, but after the death of the cell, the contents can pass freely from 

 place to place as long as there is sufficient moisture to permit of chemical activity. 



Evaporation goes on much more rapidly after the death of the cells than before, 

 but as all the cells do not die at the same time the effect of this is not noticeable. 

 The chemical changes which take place during the drying result in a decrease in 

 dry matter. This is especially true during the first stage, while <1uring the last stage 

 there may be a slight increase of dry matter due, the author thinks, to oxidation. 



The quality of the finished product depends largely upon the length of time the 

 different stages are allowed to continue. If the drying is unduly hastened the leaf 

 blade becomes too dry by the time the midrib is dry enough, and the danger is that 

 the leaf will not ferment properly. As a result of this study of fresh tobacco the 

 author finds that on properly grown plants the top leaves are heavier than the lower 

 ones and contain a relatively larger amount of dry matter. The cells and air spaces 

 are larger in the lower leaves, and the leaves dry more rapidly and burn Ijetter. In 

 the upper leaves the unit of surface ( 1 sq. cm. ) is heavier than in the lower leaves, 

 due to the greater amount of solid matter in the cells of the upper leaves. It was 

 also found that the green leaf was influenced by the time of day the tobacco was 

 cut and by the weather conditions some hours or even some days before harvest. 

 The riper the leaves were, the shorter the time needed- for drying. 



During harvest careful attention must l>e given to wet leaves, the bruising of leaves, 

 and the sweating. Wet leaves or wet places on the leaves tend to discolor the 

 tol)acco and to make it dry unevenly. Bruising affords a point of entrance for 

 mold<. 



During sweating an increase in temperature lowers the vitality of the cells, thus 

 hastening death and the completion of the first stage in drying. 



The influence of light, air, moisture, and heat are briefly discussed. In urging 

 the necessity for ventilation the author points out that in the process of drying the 

 air of the barn must be changed at least 500 times in order to carry off all the mois- 

 ture from the leaves. — h. m. pieters. 



Work with wheat in 1900, H. L. Bolley {North Dakota Sta. Rpt. 1900, pp. 

 28-3-2). — The work of wheat selection which has been in progress for several vears 

 was continued this season. Large and small grains from each of a number of selected 

 heads were sown and the resulting plants compared. In the majority of cases, the 

 greatest length of straw was in favor of the large seed. The total weight of straw 

 and grain jjroduced by 102 stools from large grains was 1,417 gm. and by the 

 same numljer of stools grown from small grains, 1.328 gm. In a second test 800 

 of the largest, plumpest, and finest colored grains and the same number of the 

 smallest possible grains which were plump, hard, and of similar fine quality were 

 selected from a graded sample of Scotch Fife wheat and grown for comparison. The 

 results showed a gain of over 10 per cent in the total weight of straw and grain in 

 favor of the large seed. The large grains also produced heavier heads. In a third 

 experiment, heads of wheat were harvested at different stages of maturity and cured 

 in a dry room, the grain being left in the straw mitil it was sown. After a germina- 

 tion test, which showed perfect germination for all the samjjles, the seeds of the 

 different lots were sown for comparison. The most rai)id growth was made by the 

 young plants from the most immature seed and the sprouts were longer than those 

 from the mature grain, but these were 3 to 4 times as strong in diameter. Owing to 



