Yield.
The average yield is twenty-five to thirty-five bushels per acre, but products of one hundred and fifteen bushels per acre have been secured. With good soil and seed the average crop may be more than doubled by a thorough preparation of the soil and the proper application of water while the rice is young and during the entire period of growth.
Rice mills (Fig. 773) have been perfected until they are a vast network of complicated machinery, taking the grain in the rough, separating the weed seeds and light grains, removing the hulls and then the bran, polishing, grading and placing each grade in sacks of recorded weight, ready for sew ing and marking. The capacities of rice mills in the United States vary from 1,000 to 10,000 bushels of rough rice per day of twenty-four hours.
The products of the rice in milling are classified commer cially, as follows : Head rice (whole grains), straights (mostly whole grains but a grade slightly below head rice), screenings (broken rice, of which there are several grades), brewers' rice (very finely broken rice used in the manufacture of beer), polish (a highly nutritious flour scoured from the surface of the kernels in polishing, sometimes incor rectly called rice flour, which latter is ground rice), rice bran (the cuticle immediately within the hull), and rice hulls (the outer covering). The approximate mill ing outturn of 162 pounds of rough rice is 98 pounds of com mercial rice, 6 pounds of polish, 28 pounds of bran and 30 pounds of hulls.
Composition of rice products.
The chemical constituents of the products of rice are as follows : Commercial or polished rice : Total nutrients, 87.15 ; protein, 7,52 ; ash, 0.73 ; fat, 0.38 ; carbo hydrates, 78.05. Rice polish : Protein, 11.06; ash, 8.45 ; fats, 5.92 ; carbohydrates, 65.97. Rice bran : Protein, 9.88 ; ash, 11.55 ; fats, 9.21 ; carbohy drates, 52.63. Rice hulls: Protein, 3.50 ; ash, 18.29 ; fat, 0.4 ; carbohydrates, 41.80 ; crude fiber, 37.50. Rice straw: Protein, 3.31 ; ash, 14.64 ; fats, 0.59; carbohydrates, 33.31; crude fiber, 32.01.
It will be noted that rice polish and rice bran remove nearly all the fats from the rice, and con sequently rice as sold on the market has little flavor. The retention of the polish, as in oriental milling, would materially increase the flavor, and if the bran were retained rice would be rich in flavor.
Definitions of terms.
The commercial terms used in the United States may be defined as follows: Rough rice, or paddy, signifies rice with the hull on; a sack is an indefi nite quantity varying from 160 to 210 pounds; a barrel is 162 pounds of rough rice; a pocket is 100 pounds of milled or cleaned rice.
Enemies.
Insects.—The principal injurious insect is the rice weevil (Calandra Oryzw). It originated in India and has gradually become common in all the rice-producing countries of the world. It is not common in overflowed fields, mainly attacking stored rice. It is readily killed by the use of carbon bisuifid.
The rice grub is the larva of one of the scara bmidm and looks like the ordinary white grub. It is killed by water.
The rice-stalk borer is the larva of a crambid moth, which lays its eggs in the early summer.
The young larva bores into the stalk, gradually working down to the roots of the plant. In the stalk it is transformed into the pupa state and in five or six days the moth emerges. Stalks affected by the borer turn white, causing a white blast.
The chinch-bug occasionally works on rice in the field, but thorough flooding is, in the main, a protection. In stagnant water, rice-worms occa sionally attack the roots and ruin the crop. The remedy is to draw off the water and allow the field to dry a few days, then reflood.
Diseases.—Occasionally a fungous disease attacks the stalk just below the head and penetrates it till the head falls over and the stalk breaks at the point of attack. This is commonly called "neck rot" or "white blast," and can be obviated by the application of lime to the soil.