36o 



Journal of Agricultural Research 



Vol. V, No. 9 



old sample, as all the leaves and straw were partially or completely 

 withered at this period. The i8- to 48-day -old samples had no withered 

 leaves, so that these analyses represent the whole plant aboveground. 



Table II. — Ash analyses of vegetative parts of the rice plant at various periods 



di; ! Percentages 

 6 §• j ia dry mat- 

 ^1 terof— 



Percentages in carbon-free ash of- 



Green leaves and 



stalks 



Do 



Do 



Do 



Do 



Withered leaves and 



stalks 



Withered leaves. . . . 



Do 



Panicles immature . . 



Panicles with ripe 



seed 



14. 6 

 20. 1 

 21.5 



37 

 61. o 



48.5 



17-75 

 14.97 

 22. 21 

 16.95 

 13-28 



20. 23 

 30.1 

 27. 60 



56.88 

 56.34 

 62.56 

 64.82 

 67.71 



74.00 

 83- SI 

 85-10 

 78- IS 



4-47 

 4. 10 

 5-37 

 4- 52 



1.69 

 .80 

 • 68 



The percentage of iron in the ash of the green straw and leaves decreased 

 regularly and rapidly with the maturity of the plant, the greatest decrease 

 being from the i8-day-old to the 26-day-old sample.* The withered 

 leaves had a relatively high percentage of iron. This may be due to the 

 other samples, consisting of both leaves and stalks, or to the fact that 

 the withered leaves of the yy and 103-day-old sample were the leaves that 

 appeared first — i. e., those forming a large part of the first samples. 



The varying percentages of iron in the ash of the green straw and 

 withered leaves agree with some of the results obtained by Arendt ^ with 

 oats. He found that the lower leaves of wheat, which must have been 

 withered at the later periods of analysis, contained increasing percentages 

 of iron, which were much greater than the percentages of iron in the ash of 

 the upper leaves. 



The lower percentages of potash, phosphoric acid, sulphur, chlorin, and 

 nitrogen in the ash of the withered leaves may be due to translocation of 

 these elements preceding death of the leaves or to loss by leaching after 

 death of the tissue. 



In Table III is given the ash composition of the roots and of the whole 

 plant aboveground. The roots for analysis were washed with great care, 



1 These results are in accord with many analyses of green rice straw made previously. Four samples of 

 rice straw from plants grown in four different soils for 25 days contained from 2.76 to 1.98 per cent of iron 

 (FesOs) in the ash, while samples from a crop grown 84 days had 0.31 to 0.18 per cent, and samples from a 

 129-day-old crop had but 0.12 to 0.10 per cent of FejOa in the ash. (Gile, P. L., and Ageton. C. N. The 

 effect of strongly calcareous soils on the growth and ash composition of certain plants. Porto Rico Agr. 

 Exp. Sta. Bui. 16, p. 31, 1914.) 



2 Arendt, R. F. E., Untersuchungen iiber einige Vorgange bei der Vegetation der Haferpflanze. In 

 Landw. Vers. Stat., Bd. i, p. 31-36. 1859- 



