THE QUALITY OF WHEAT IN OKLAHOMA DRILL BOXES By TERRY WAYNE SEMMEL \~ Bachelor of Science in Agriculture Oklahoma State University Stillwater, Oklahoma 1979 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE December, 1981 THE QUALITY OF WHEAT IN OKLAHO~..A DRILL BOXES Thesis Approved: ii 1100023 PREFACE The author wishes to express his sincere appreciation to his major adviser, Dr. F. E. LeGrand, for his continuous support and direction throughout this study. Without his encouragement this study would not have been possible. Appreciation is also expressed to the committee members, Dr. E. L. Smith, Dr. T. F. Peeper, and Dr. R. L. Westerman for their invaluable assistance in the course of this study. A note of thanks is given to Dr. P. L. Claypool for his assistance in providing the programming needed for statistical analysis. Grateful acknowledgement is made to the Oklahoma Crop Improvement Association for the assistance in laboratory analyses of the samples collected. In addition, appreciation is extended to the many County Extension Directors and Area Agronomists for their efforts in supplying samples for the study. Finally, gratitude is expressed to the Oklahoma Wheat Commission for the finiancial aid that made this study possible. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION 1 II. LITERATURE REVIEW . 3 III. MATERIALS AND METHODS 10 IV. RESULTS AND DISCUSSION • 17 Source of Seed . 17 Seeding Rates • • 22 Use of Certified Seed • 25 Varieties • • • • • 28 Varietal Purity • • • • • • • • • • • . 31 Weed Seed Content • • • • • • . 39 Other Crop Seed • • • . 45 Cleaned Seed • • 47 Treated Seed • • • • • • • • • 52 Mechanical Purity and Inert Matter Percentages 53 V. SUMMARY AND CONCLUSIONS . 60 A SELECTED BIBLIOGRAPHY • 64 APPENDIXES . 66 APPENDIX A - PHENOL TEST . 67 APPENDIX B - SCIENTIFIC NAMES OF COMMON WEEDS, NOXIOUS WEEDS AND OTHER CROPS • • • 68 APPENDIX C - PERCENT OF GROWERS PLANTING SEED TREATED WITH FUNGICIDES WITHIN EACH COUNTY SURVEYED CATEGORIZED BY SEED SOURCE • • • • • • • • . 70 APPENDIX D - PERCENT OF GROWERS PLANTING SEED TREATED WITH INSECTICIDES WITHIN EACH COUNTY SURVEYED CATEGORIZED BY SEED SOURCE 71 APPENDIX E - DEFINITION OF TERMS • 72 iv LIST OF TABLES Table Page I. Canada Seed Standards for Barley . 5 II. Number of Samples Collected From Four Seed Sources in Sixteen Counties of Oklahoma • . 18 III. Source of Seed in Percent of Samples Collected in Sixteen Oklahoma Counties • • • • • • • . 19 IV. Source of Seed in Percent of Acres Planted in Sixteen Oklahoma Counties • • • • • • . 21 v. Average Seeding Rate in Pounds Per Acre of Four Seed Sources Within the Surveyed Counties •• . 23 VI. Average Seeding Rate of Twenty-six Varieties of Wheat Within Each County Surveyed in Pounds Per Acre. 24 VII. Field Standards of Certified Classes of Wheat • 26 VIII. Seed Standards of Certified Classes of Wheat 27 IX. Use of Certified Wheat in Percent of Growers and Acres Sampled • • • . 29 X. Percent of Acres Planted to Each Correctly Labeled Variety in the Sixteen Counties Surveyed and in the 1957 Survey • • • • • • • • • • • • • • • 30 XI. Percent of Growers Planting Mislabeled, Unknown or a Mixture of Varieties • • • • • • • • . 32 XII. Acreage Percentages of the Wheat Varieties Collected within Each County Surveyed . 33 XIII. The Number and Percent of Survey Common and Survey Pedigreed Samples Within Arbitrary Varietal Purity Classes • • • • • • . 36 XIV. The Percent of Survey Samples Falling Into Arbitrary Varietal Purity Classes within Four Seed Sources • • • • • • • • • • • • 37 v Table Page XV. The Number of Survey Samples Falling Into Arbitrary Varietal Purity Classes within Four Seed Sources • • • • • • • • • • • • 38 XVI. The Percent of Survey Samples Within Arbitrary Varietal Purity Classes Categorized by Years from Certification • • • • • • • • • • • • • 40 XVII. The Year of Release and Percent of Twenty-four Varieties Within Arbitrary Varietal Purity Classes 41 XVIII. Average Number of Total Weeds Per Pound in Survey Samples Within Each County Surveyed Categorized By Seed Source • • • • • • • • • • • • 43 XIX. Average Number of Noxious Weeds Per Pound in Survey Samples Within Each Comity Surveyed Categorized By Seed Source • • • • • • • • • • • • • • • • • . 44 XX. Average Number of Common Weeds Per Pound in Survey Samples Within Each County Surveyed Categorized By Seed Source • • • • • • • • • • • • • • • • 46 XXI. Average Number of Other Crop Seed Per Pound in Survey Samples Within Each County Surveyed Categorized By Seed Source • • • • • • • • • • • • • • • • • • • • • 48 XXII. Average Percent Purity and Inert Matter and Average Number of Noxious and Common Weeds per Pound for Sixteen Oklahoma Counties • • • • • • • • 50 XXIII. Percent of Growers Planting Cleaned Seed Within Each County Surveyed Categorized by Seed Source • • • • • 51 XXIV. Percent of Growers Planting Laboratory Tested Seed within Each County Surveyed and Categorized by Seed Source • • • • • • • • • • • • • 54 XXV. Average Percent Purity of Samples from Sixteen Oklahoma Counties Categorized by Seed Source • • • • • • 56 XXVI. Average Percent Inert Matter of Samples From Sixteen Oklahoma Counties Categorized by Seed Source • • • . 57 XXVII. Average Germination Rate of Samples From Sixteen Oklahoma Counties Categorized by Seed Source • • • • • • • 58 vi LIST OF FIGURES Figure Page 1. Highway Map of ~~jor County Showing Sections Randomly Selected Within Each Township •• 11 2. Questionnaire • • • • • • • • . • • • 13 3. Illustration of the Numbering Sequence of a Sectionalized Township • • • • • • . 14 vii CHAPTER I INTRODUCTION Wheat is the most important cultivated crop in Oklahoma. Wheat producers should not only be concerned with fertilizer, herbicide, and equipment needs but also the quality of seed they plant. What is meant by high seed quality? One of the main components of good seed quality is the absence of noxious and common weeds. Other qualities, however, such as high germination, mechanical purity, and genetic purity percent­ ages, and low inert matter and other crop percentages are also essential for high quality seed. Before a lot of seed can be labeled as a certified class of wheat it must first exceed the minimum standards for germination rate, mechan­ ical purity, inert matter, other crop seed, weed seed, and genetic purity. Thus, certification insures high quality seed. To insure that the quality of planting seed will not become a limiting factor in wheat production farmers need to make certain their planting seed is high quality. Most wheat farmers plant their own seed or seed obtained from a neighbor. Only a small portion purchase seed known to be of high quality. The use of certified seed has never been widely practiced in Oklahoma. In 1957, only 1.8% of the total wheat acreage was planted to certified seed (S). Only 0.3% was planted to certified wheat in 1980 ( 16). 1 2 Some 75% of the wheat acreage in Oklahoma is planted in 22 count­ ies. Each of these major ~.rheat producing counties will plant over 150,000 acres to wheat annually. This study was initiated to determine the quality of wheat seed planted in 16 of these counties. CHAPTER II LITERATURE REVIEW Seed quality has long been recognized as one of the most often overlooked factors of many that limit crop production. Obviously, the production of a superior product, in terms of both quality and quantity, cannot be expected when poor quality seed is planted. Drill box surveys are designed to determine the quality of seed actually planted by farmers and have proven to be valuable tools in many states over the past 30 years in the assessment of seed quality. They have often been conducted on small grains by Crop and Seed Improvement Associations throughout the United States and Canada. Letters were written to these organizations requesting copies of their most recent drill box surveys. Of the 21 states responding, 11 had conducted drill box surveys. These 11 states responded by sending a total of 16 surveys. It was from these 16 sur­ veys that this literature review was compiled. It should be noted that not all of the drill box surveys were formally published. The data of some surveys were disseminated via news letters, inter-departmental memorandums, and private correspondence. There are several options available in the execution of drill box surveys. Most researchers made use of Extension Personnel to collect their samples. Extension Personnel included Area Agronomists, District Agriculturalists, Agricultural Fieldmen, and County Extension Directors (1, 3, 5, 7, 9, 11, 13, 14, 19, 20). Some studies involved Vocational 3 4 Agriculture Instructors and F.F.A. Chapters (1), while still others involved 4-H Chapters (7). A number of surveys did not mention the personnel used to collect the samples (2, 8, 10, 12). One essential component of any drill box survey is complete random­ ization of the sampling sites. Nine of the surveys reviewed delegated the responsibility to provide randomization to the Extention Personnel (1, 3, 7, 9, 11, 13, 14, 19, 20). No mention of the approach to provide randomization was made in four surveys (2, 8, 10, 12). The study con­ ducted at Kansas was the only survey tabulating results for wheat that mentioned randomization of samples had been insured by the Crop Improve­ ment Association (9). In this study 1,524 names of Kansas wheat pro­ ducers were selected at random from a list of producers obtained from the State