662 



WHEAT 



WHEAT 



together, but soon the wheat begins to joint or 

 "shoot" and the stalks grow rapidly, while the 

 space between the nodes increases until the full 

 height of the plant is attained. The range of the 

 height varies from two to six feet, and there does 

 not appear to be any close relationship between 

 this height of straw and the yield of grain. The 

 less moisture in the soil the smaller the proportion 

 of straw to grain. As the plant attains develop- 

 ment the spike pushes up until it rises above the 

 growth of foliage below, and a mature field of 

 wheat shows a uniform surface of erect spikes. 

 At this stage of growth the leaves at the surface 

 of the ground, together with those attached to each 

 node, wither and fall, the whole plant turning a 

 golden yellow color. 



The ability of the wheat plant to tiller or stool, 

 throwing up additional stalks, is a marked charac- 

 teristic. It often occurs that such stools may show 

 twenty to even one hundred stalks starting from a 

 single grain. This habit of tillering is governed 

 by the variety and also may be modified by the 

 climatic conditions of the season. It will readily 

 appear that what is called the " stand " of wheat 

 may depend in a large measure on the freedom 

 with which the plant may send up these, addi- 

 tional shoots. 



The wheat head. — A discussion of the variations 

 existing in the different types of wheat as shown 

 by a study of the spike or head will be given under 

 the classification of varieties. A somewhat tech- 

 nical description of the head is, however, necessary 

 in order to make clear many references in this 

 article. The description given is condensed from 

 Bulletin No. 7, Bureau of Plant Industry, United 

 States Department of Agriculture, p. 9. 



" The flowering and fruiting cluster at the sum- 

 mit of the stem of a wheat plant is called the 

 ' head ' or ' spike.' The part of the stem running 

 through the spike, on which the flowers or kernels 

 are borne, is called the 'rachis.' The rachis is 

 divided by a number of joints, or nodes, and at 

 these nodes on alternate sides of the rachis are 

 attached the spikelets, — the several small second- 

 ary spikes which together with the rachis make 

 up the spike proper. The short branch running 

 through each spikelet is known as the ' rachilla.' 

 Inserted on the rachilla are several concave scales 

 which are called the 'glumes.' The two lowest 



F)g. 893. Floret of wheat 

 {.Triticum scttiw/m). 



grain, is subtended by a single glume, known as 



the ' flowering glume.' Each flowering glume has 



a longitudinal nerve which at the summit extends 



into a prominent ' awn ' or ' beard.' On the inner 



or creased side of the 



grain or berry, filling it 



very closely, and more or 



less hidden from view by 



the flowering glume, is 



borne the 'palea' or 'palet,' 



a thin scale with two 



nerves. The flowerless 



and flowering glumes and 



the palets are spoken of 



collectively as the 'chaff'." 



In Fig. 893 is shown a 



floret enlarged. 



In many varieties the 

 outer glumes have their surfaces covered with 

 short soft hairs which give the heads of wheat a 

 velvety appearance. This velvet or fuzz, while 

 present in many very productive types and varie- 

 ties, is not considered by growers a desirable 

 characteristic. 



It would be easy to make a classification of 

 wheat based on the striking differences of the 

 spike, and to some extent these are considered, but 

 such division can hardly be said to have a botanical 

 basis. 



Production. (T. L. Lyon.) 



The report of the Twelfth census of the United 

 States states that in the decade 1890 to 1900, the 

 area planted to wheat in this country increased 

 from 33,579,514 acres to 52,588,574 acres, or 56.6 

 per cent. In the preceding decade there had been 

 a decrease of 5.2 per cent. The acreage reported in 

 1900 was 48.4 per cent greater than that of 1880. 



The increase in production of wheat has been 

 about proportional to that of acreage. The largest 

 yield in this country for any one year was 748 

 million bushels, produced in 1901. The yield per 

 acre for the last three decades has remained prac- 

 tically the same, but the value per bushel and 

 consequently per acre has steadily declined. The 

 cost of producing a bushel of wheat has likewise 

 decreased in amount. These facts are brought out 

 in the following table, taken from the Statistical 

 Abstract of the United States for 1906 : 



and outermost of these contain no flowers or 

 kernels and are designated as the 'flowerless 

 glumes.' Above these, arranged alternately, are 

 borne the flowers, rarely less than two, or more 

 than five. Each flower and, as it matures, each 



The United States leads all countries in the pro- 

 duction of wheat. The other large wheat-producing 

 countries are Russia, India, France and Austria- 

 Hungary, while Canada and the Argentine Republic 

 are rapidly increasing their output. Europe is still 



