174 



SCIENCE. 



[Vol. VII., No. 159 



pression which is the accompaniment of a murky 

 atmosphere. 



WASTE IN WHEAT-CROPS. 



In most of the wheat-producing regions of North 

 America a yield of thirty bushels per acre is ex- 

 ceptional, and one of forty or more, remarkable or 

 extraordinary. Most farmers are content to get a 

 return of fifteen or eighteen bushels, and only 

 twelve and one-half is the average yield through- 

 out the United States. The usual increase is thus 

 only about ten or twelve fold, and only very ex- 

 ceptionally thirty or more fold. Doubtless most 

 persons who have given the subject any attention 

 wonder why it is that among all farm products 

 the return should be so small for the amount of 

 seed sown. In a late number of the Contemporary 

 review, Dr. Paley has discussed this subject, and 

 brought out a number of interesting facts. 



A single grain of wheat will produce from five 

 to seven ear-bearing stalks : experiments seem to 

 show that the latter is the normal number. The 

 single blade ' spears ' first into three, then into five 

 or more side-shoots, every one of which, separated 

 and transplanted by hand, will form a new plant. 

 Each ear contains, on fairly good land, from fifty 

 to sixty, sometimes even seventy, grains. Three 

 or four of the terminal grains are generally 

 smaller, or otherwise defective, and are rejected 

 in winnowing and screening the wheat. But as 

 a fair average, on a moderate estimate, a single 

 grain can produce three hundred, and there is a 

 possibility of four hundred, or even more. This 

 means, of course, that every bushel sown can, 

 theoretically at least, yield three hundred bushels ; 

 but, as we have seen, the actual yield is only a 

 small portion of this. 



In tracing, then, the bushel sown to the twelve 

 or fifteen bushels that come into the farmer's 

 granary, we have to inquire what proportion of 

 the seed germinates, how much of it is de- 

 stroyed by birds, mice, insects, and how much 

 grain is shed from over-ripeness, or lost in harvest- 

 ing and threshing. A very considerable quantity, 

 without doubt, is the aggregate loss from these 

 causes combined. Still the immense difference 

 between the quantity that can be, and theoreti- 

 cally ought to be, produced, and that which actu- 

 ally goes into the wheat-bin, remains to be ac- 

 counted for. The loss of grain in the various 

 processes of harvesting evidently must be much 

 greater than is commonly supposed. If one take 

 a ripe wheat-ear, and strike it on a table, he will 

 see some grains fall out ; and, if he examine 

 where a wheat-sheaf has fallen, he will find not a 

 few kernels that have been shed. Certainly the 



k volunteer ' growths after harvesting are sufficient 

 evidence of waste. 



To ascertain, with something like accuracy, the 

 actual produce of the wheat-plant, Dr. Paley 

 planted a small piece of garden-ground, of moder- 

 ate wheat-growing quality, with three separate 

 parcels, each of fifty average wheat-grains. Of 

 these three parcels, the first (A) was sown broad- 

 cast ; the second (B) was set in two rows, after the 

 manner of drilled wheat ; the third (C) in separate 

 grains six inches apart, — all carefully covered 

 with earth. Besides these, he planted twelve grains 

 three and a half inches deep (D), and three grains 

 in each of three holes, one inch deep (E). Of group 

 A, twenty-five came up, and produced one plant 

 of three stalks, six of four, three of five, seven of 

 seven, and three of nine, with a total of one hun- 

 dred and forty-eight ear-bearing stalks ; of B, 

 thirty plants grew, giving two of two stalks, eight 

 of three, one of four, ten of five, six of seven, two 

 of ten, and one of eleven, with a total of one hun- 

 dred and fifty-one ; of C, thirty-two plants grew, 

 producing a total of one hundred and forty-eight 

 ear-bearing stalks ; of D, not a single one germi- 

 nated ; and of E, only one, which did not thrive 

 well. The nearness of the totals of the first three 

 is remarkable. If thus we estimate an average of 

 three stalks from each grain sown, and for each 

 ear fifty sound grains, we should have a yield of 

 one hundred and fifty fold. 



What, then, are the reasons of such an extraor- 

 dinary difference between theory and practice ? 

 Besides the various kinds of blight, such as smut 

 and mildew, affecting the straw or the ear, and 

 greatly diminishing the production, there are other 

 causes why wheat is said to thresh out badly, 

 which are less visible while the crop is standing. 

 One of these is the partial filling of the ear : there 

 is more chaff than there should be in proportion to 

 the grain. There is a popular idea about the 

 wheat-plant which is entirely erroneous. It is 

 thought, that, if high winds prevail while the 

 wheat is in flower, the anthers, which are seen 

 dangling from the ears, will be blown off, and the 

 grain will not set through the loss of pollen. Year 

 after year we see this stated in agricultural papers 

 and grain reports. But the fact is, these anthers, 

 when protruded, have already performed the office 

 of impregnation, which takes place within the 

 closed glumes. The ' flowers ' seen hanging down 

 are exhausted anthers, and wholly useless. The 

 following experiments seem conclusive proof of 

 this. Let one gather a dozen green wheat-ears 

 from a plant that is just beginning to flower, and 

 keep them for an hour or two in a warm room in a 

 glass of water. The anthers may then be watched 

 in succession in the very act of being protruded 



