t.ftevico State Co\\ege oracy, Nev1 "· " m4r 1Jtuiurrsity nf tliuursnta AGRICULTURAL EXPERIMENT STATION BULLETIN 143 MINNESOTA WHEAT INVESTIGATIONS SERIES III COMPOSITION AND QUALITY OF SPRING AND WINTER WHEATS CROPS OF 1912 AND 1913 BY C.H. BAILEY CEREAL TECHNOLOGIST, DIVISION OF AGRICULTURAL CHEMISTRY UNIVERSITY FARM, ST. PAUL SEPTEMBER 1914 AG RI CULTURAL EXPERIMENT STATION STATION STAFF A. F. WooDs, M.A., D.Agr., Director ]. 0. RANKIN, M.A., Editor HARRIET W. SEWALL, B.A., Librarian T. ]. HORTON, Photographer T. L. HAECKER, Dairy and Animal Husbandman M. H. REYNOLDS, B.S.A., M.D., D.V.M., Veterinarian ANDREW Boss, Agriculturist F. L. WASHBURN, M.A., Entomologist E. M. FREEMAN, Ph.D., Plant Pathologist and Botanist JOHN T. STEWART, C.E., Agricultural Engineer R. VI/. THATCHER, J\1.A., Agricultural Chemist F.]. ALWAY, Ph.D., Soils Chemist RICHARD WELLINGTON, M.S., Chairman of Horticultural Committee E. G. CHEYNEY, B.A., Forester A. D. vVILSON, B.S. in Agr., Director of Agricultural Extension and Farmers' Institutes L. D. H. WELD, Ph.D., Agricultural Economist A.]. McGi:;rnE, B.Agr., Superin_tendent, North Central Substation E. C. HIGBIE, M.A., Superintendent, West Central Substation C. G. SELVIG, l\LA., Superintendent, Northwest Substation CHARLES HARALSON, Superintendent, Fruit-Breeding Farm, Excelsior M. J. THOMPSON, 1\1.S., Superintendent, Northeast Substation DIVISION OF AGRICULTURAL CHEMISTRY R. W. THATCHER, M.A., Agricultural Chemist R. M. WEST, B.A., Assistant Agricultural Chemist C.H. BAILEY, B.S.A., Cereal Technologist CORNELIA KENNEDY, B.A., Assistant Agricultural Chemist ]. J. WILLAMAN, M.S., Assistant Agricultural Chemist TABLE OF CONTENTS Page Introduction 5 Methods employed 5 Factors of importance 7 Relation of composition to quality 9 Plan of the investigation 9 General characteristics of the 1912 crop 10 Varieties of wheat represented 11 Source of the samples 12 Results of tests of the 1912 crop samples 14 Spring wheats 14 Winter wheats 22 General characteristics of the 1913 crop 28 Results of tests of the 1913 crop samples 30 Spring wheats 30 Winter wheats 36 Averages of tests of 1911, 1912, and 1913 crop samples 43 Dates of seeding spring and winter wheats 45 Comparison of spring and winter wheat samples 46 Bearded spring or velvet chaff wheat 48 Marquis wheat 54 Bearded Bluestem, or Humpback wheat 55 Relation between the percentage of crude protein m wheat and flour 56 Summary 58 ILLUSTRATIONS Fig. 1. Source of 1912 crop samples 13 Fig. 2. Source of 1913 crop samples 29 Fig. 3. Crude protein content of wheat and flour samples of 1911, 1912, and 1913 crops 57 MINNESOTA WHEAT INVESTIGATIONS CROPS OF 1912 AND 1913 By c. H. BAILEY INTRODUCTION The wheat grown in any section, even when of the same varieties, varies in quality and composition from year to year. These differences are principally attributable to the climatic conditions prevailing during the different seasons. The total quantity and distribution of the rain­ fall as influencing the moisture available to the plant at different stages of growth is one of the most potent factors affecting the composition of the wheat crop. Sunshine, temperature, wind, humidity, consistency of the soil and subsoil, drainage, and plant diseases also have a greater or less effect. In recognition of these facts it was deemed advisable to continue for a number of years the investigations of Minnesota wheats commenced in 1911, and reported in Bulletin 131 of this Sta­ tion. The studies have included the hard winter wheats of the crops of 1912 and 1913, as well as the spring wheats grown during the same seasons. The results of the tests and analyses of these .samples are presented in this publication. It is proposed to continue the investiga­ tions for· several years more, in order to observe the composition of wheat of the different types and varieties under varying conditions, and to trace the relation between environment and the composition and quality of Minnesota wheats. METHODS EMPLOYED The laboratory methods employed in these investigations were described in more or less detail in Bulletin 131. Certain of the methods were slightly modified, however, before the work of the second season was begun. A third pair of rolls was added to the experimental flour mill shown on page 12 of Bulletin 131. These rolls have 24 corruga­ tions to the inch, and are employed in making the fourth and fifth breaks during the process o,£ flour-production. The corrugated rolls 5 6 MINNESOTA WHEAT INVESTIGATIONS in the original equipment have 16 corrugations to the inch, and the first three breaks are made on them. The method of calculating the percentage of total flour has been changed since the completion of the work of the first season. The calculations were originally based on the total weight of material re­ covered, this being the practise in the flour laboratory before the in­ vestigations of the crop of 1911 were commenced. In computing the percentage of total flour obtained from the 1912 and 1913 crops, the calculations were based on the weight of cleaned wheat used rather than on the weight of material recovered. Since the percentages so calculated were necessarily lower, the results of the milling tests of the CFOP of 1911 were recalculated, and the figures used in compari­ sons between them and the data from later tests, shown in Table V, are computed in the same manner. The value of the results obtained through the use of ~ small ex­ perimental mill of the type employed in these investigations depends in large measure upon the manner in which the mill is handled. If an attempt is made to reduce the wheat to flour in two or three breaks and about twice as many reductions, it is probably true that little value can be attached to the results of the tests. The criticism directed against the use of this equipment has apparently resulted in large part from such use of it in the hands of inexperienced laboratory assistants having little knowledge of the technology of milling. The use of larger machines, but the same short system of milling, does not improve the situation. In fact, such an outfit is likely to be of even less value than the small mill, since it is usually made automatic in operation, which results in less flexibility. The stream of wheat must be reduced to flour in the few breaks and reductions provided, or a large portion of the floury material escapes reduction and is lost in the feeds. If, however, the wheat is reduced gradually with the small mill, fair yields of a relatively high-grade flour can be obtained which do not compare unfavorably with commercial flours manufactured in a merchant mill. The fact that there is no provision for purification of the middlings results in the flour containing small specks of branny substance which slightly affect the appearance of the dry flour, but are less noticeable in the baked loaf. In these tests at least five breaks were made on the two stands of corrugated rolls and from eight to eleven reductions (as computed in ordinary flour-milling practises) on the smooth rolls. This is a longer system of milling than is provided for in many of the smaller mills of the State. While somewhat superior flours can doubtless be produced with a long, automatic system, which includes middlings-purification, the results of the tests of the samples, reported CROPS OF 1912 AND 1913 7 · in this bulletin, are considered comparable with each other. Further­ more, when a white, clean flour which bakes into white bread of good texture and flavor can be produced with this equipment, it seems rea­ sonable to conclude that at least equally good flour should be produced from the same raw material in a large merchant mill. The weight of 1,000 kernels of the cleaned wheat was determined and in the tables following these data are substituted for the statement of comparative condition given in the tables published in Bulletin 131. In making this determination 500 kernels of .the samples of wheat, previo.usly freed from other grains ancl foreign matter, were weighed, i'he weight being multiplied by two. The acidity of the flour was determined in all cases, but the per­ centages were omitted from the tables. They were employed to aid in the elimination of unsound material, the results of tests of which might prove misleading. The flours reported in this bulletin were all milled from sound wheat, as shown by the usual inspection and the acidity test. FACTORS OF IMPORTANCE The factors of principal importance and the interpretation of the results of the tests are discussed at some length in Bulletin 131. A brief recapitulation follows, and the interested reader is referred to that bulletin for a more extended consideration of this matter. From the market standpoint the quality of wheat may be considered under two heads: ( 1) the milling quality and (2) the baking quality of the flour produced. Milling quality.-Since flour is the most valuable mill product, those wheats which yield the highest percentages of flour are more valuable than those from which lower percentages are obtained, assum­ ing the flours produced to be of the same value. The percentage of flour in wheat is not an absolute quantity. Careful separations of the different portions or structures of the average plump wheat kernel have shown that the endosperm or "floury" portion represents from 82 to 86 per cent of the whole kernel by weight.1 Only from 72 to 75 per cent of the kernel is recovered as flour in milling, however, and the lower grades of flour even contain fragments of portions of the kernel other than the endosperm.