Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Oata Analysis and Synthesis (CINOAS) * at Purdue. University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 33 (thesis year 1988) a total of 13,273 theses titles from 23 Canadian and 1 85 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 33 reports theses submitted in 1988, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

The utilization of nitrapyrin in nitrogen (N) management may be an important tool for increasing soft red winter wheat yields in Missouri. The objectives of this study were to: (1) Determine the duration of ammonium retention in the soil profile during fall and winter growth periods from anhydrous ammonia fertilizer treated with nitrapyrin(2-chloro-6-(trichloromethyl) pyridine); (2) Evaluate fall and split applications of anhydrous ammonia with or without nitrapyrin for soft red winter wheat in Missouri; and (3) Relate crop yield to NH$\sb4\sp{+}$/NO$\sb3\sp{-}$ soil ratios. Anhydrous ammonia was applied with and without nitrapyrin on a Mexico silt loam (fine montmorillonitic, udolic ochraqualf). Three days after application of anhydrous ammonia, soil samples were collected from the injection zone (IZ) and the surrounding profile up to 8 cm from the IZ. Higher levels of ammonium (NH$\sb4\sp{+}$) were retained in the soil profile in plots treated with nitrapyrin during both 1991-92 and 1992-93 sampling periods. Overall nitrate (NO$\sb3\sp{-}$) levels in the soil profile increased during the first three weeks of the study, but then decreased following wheat establishment and remained relatively low during both 1991-92 and 1992-93 sampling periods. There was a negative relationship between declining NH$\sb4\sp{+}$ levels and cumulative heat units in treatments with and without nitrapyrin during both growing periods. Nitrapyrin improved NH$\sb4\sp{+}$ retention in the soil profile during fall and winter sampling periods. There was no yield response to improved NH$\sb4\sp{+}$ retention by nitrapyrin across sites during the three year study. Yield components and harvest index (HI) were not influenced by split N treatments with or without nitrapyrin. Nitrapyrin did not increase nitrogen use efficiency (NUE), however, NUE increased with increasing spring N application. Lack of yield response to nitrapyrin clearly indicates that nitrapyrin is not an important tool to be incorporated into the N management for soft red winter wheat production in Missouri.

Wheat, the second cereal crop, is very important in India, because it is the staple food of most of the people of northern, western and central India, where winter is long or medium in duration. Now, with the arrival of dwarf wheat, it is grown in eastern parts of India also, where winter duration is short. Though huge amount of research works, on different aspects, are being done in different parts of the country, but management oriented book on wheat, is rare. Therefore, on management view points, the book entitled, `Wheat Crop Management' has been written in 17 chapters covering new strategies for wheat production improvements. Besides this, 138 tables and 22 figures, have been added to it. This book will be useful to both the undergraduate and postgraduate students of Agronomy of all the agricultural colleges/universities. This book will also be useful for students, Research Institutes run by ICAR, Students of the agricultural training centres for references.