630 THE SMALL GRAINS 



often on a large scale, in the same manner as other cereals 

 are gathered in the north and west (Fig. 183). 



RICE PESTS 



708. Weeds form one of the chief difficulties with 

 which the rice-farmer must contend. Many grasses and 

 some other plants are adapted to the same conditions that 

 are favorable to the growth of rice. These weeds increase 

 the cost of production, reduce the yield, and injure the 

 grade of the grain, thus lowering the price. 



As it is expensive to eradicate weeds, it is better to 

 prevent their introduction. The irrigation water brings 

 many foreign seeds. The community thrashing outfit 

 also is a weed distributer. Weeding by hand should be 

 done at once on the appearance of weeds, unless there 

 are so many that the cost would be prohibitive. If the 

 latter is true, clean culture must be practiced, and crop 

 rotation, if a satisfactory crop to follow rice is available, 

 as recommended in Chapter XVII. Planting the field 

 levees with rice will reduce the area for weed growth. 



709. Red rice (Oryza sativa, Linn., various varieties). 

 The worst weed of the rice fields of this country, except 

 in California, is red rice, which is found in all rice countries 

 of the world. The coat of the caryopsis is red, and the 

 color does not refer to the hull. Red rice is introduced 

 only through its occurrence in the seed. The importance 

 of pure seed in rice seeding is, therefore, made evident. 

 Red rice is readily distinguished . from cultivated rice in 

 the field, by its loose, open, drooping panicle, with few 

 kernels on the branches. Even the individual kernels 

 can be detected by the experienced rice-grower. The 

 weed may be prevented from becoming established in a 



