Enemies.
wheat plant has many enemies to contend with in the form of insect pests, fungous diseases and weeds of many sorts. The two most injurious insect enemies are the chinch-bug and the Hessian fly (Figs. 905-907). The annual losses caused by these two pests in the wheat-fields of the United States is beyond estimate, but will run into millions of dollars. Remedies to counteract their ravages are largely preventive ; in the case of the chinch-bug, by clean tillage and rotation of crops, and of the Hessian fly by late seeding, burn ing stubble and otherwise hindering the propaga tion of the brood. Other insect pests may at times cause local damage to the wheat crop, but are of less importance.
rusts commonly occur on wheat, the early orange leaf-rust (Puccinia and the late stem-rust (Puccinia graminis, occurring also on oats). These rusts may also destroy the crop within a few days. Rust is now being con trolled by growing resistant varieties. Of wheat smuts there are two : The loose smut (Ustilago tritici) matures its spores at blossoming time, the then drain and dry. Care must be taken to apply the solution to all vessels and machinery used wherever the seed might become infested by contact.
Loose smut is not controlled by either of these methods. No entirely satisfactory method is known.
A modified form of hot-water treatment is recom mended.
Literature.
Klippert, The Wheat Plant ; Sargent, Corn Plants; Lyon and Montgomery, Examining and Grading Grains ; Hunt, The Cereals in America ; Snyder, Chemistry of Plant and Animal Life ; Edgar, The Story of a Grain of Wheat ; Jago, Milling of Wheat ; Kornicke and Werner, Handbuch d e s Getreidebaues ; Schindler, Der Weizen in Seinem Beziehung zum Klima ; Salms- Laubach, Weizen land Tulpe, and deren Geschichte, Leipzig, 1899 ; Report of the Twelfth Census of the United States. Bulletins of the Division of Physiology and Pathology of the United States Department of Agriculture : No. 16, Carleton, Cereal Rusts of the United States ; No. 24, Carleton, Basis for the Improvement of American Wheats ; No. 29, Hays, Plant Breeding. Bulletins of the Bureau of Plant Industry : No. 3, Carleton, Macaroni Wheats ; No. 47, Scofield, Description of Wheat Varieties ; No. 78, Lyon, Improving the Quality of Wheat ; No. 79, Harter, Variability of Wheat Varieties in Resistance to Toxic Salts. Office of Experiment Stations, Bulletin No. 11. The experiment station publications, and many others that may be traced through the Ex periment Station Record.