360 The Philippine Journal of Science 1922 
fluenced by several factors; namely, climatic conditions during 
plant growth, seasonal variation, type of soil, and nature of 
fertilizers used. All other factors being identical the effect of 
seasonal variation alone on the composition of the grain is shown 
in Table 4. 
TABLE 4.—The effect of seasonal variations in the water-free composition 
of grain at maturity. 
Spring 
crop. Fall crop. 
Per cent.| Per cent. 
PURROMONS oo nace Nau cae nea eee oe ak ak. ca a eee eiene 1.24 1,22 
MOMMA rere See ao cco oe coe ee ek Saou aa eghentes Soe 0.41 0.39 
PROBLEMS tres piace, See or es 0.92 0.83 
Renae St et rns Co te oe ee es 83.80 | 80,29 | 
As the seasonal variation in this country is very slight through- 
out the year, its effect can be practically eliminated from consid- 
eration. This would seem to suggest that the problem of im- 
proving the quality of rice resolves itself into a proper control 
of fertilizers, methods of cultivation, and irrigation. The effects 
of different fertilizers on the rice composition can be seen from 
Table 5. : 
TABLE 5.—Water-free composition at maturity of grain. 
iti Check | Mineral | Nitrogen 
ene, Plate I. | Plate II. | Plate 111.) tert 
’ Per cent,| Per cent.| Per cent.| Per cent. 
Nitrogen _ 
shuns. scCuR eevee ew oo, 1.36 1.36 1.31 1.24 
1 ot SES ANSP RS Sah a Sect SE ES 0.39 0.44 0. 42 0. 41 
TONNE MRI cos is ee sees eee 0.98 0. 92 0.89 0, 92 
Mls Seca ritual Seniel Sh gy je byes nket se 0.02 P 0. 02 
yey aren ot CREE Sis SRS RUSE rece ieee eR es OF 0.25 
CARDOMPOCRMNNMCte re er eS 8 79.66 80. 97 88.52 | 88.80 
Thus, by the use of a complete fertilizer, the carbohydrate con- 
tent has been improved from 79.66 per cent to 83.80 per cent, an 
increase of 4.14 per cent, this at the expense of protein matter, 
as the table shows. However, in the mineral plate, the nitro- 
gen content remains the same, while the carbohydrates have 
been increased. It is possible, by the use of proper proportions 
of the ingredients in the fertilizer, to increase both the carbohy- 
drate and the protein contents. 
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