On the year 2013, it was one hundred years since the birth of Efraím Hernández Xolocotzi, devoted professor from the National Agriculture School, today Autonomous University of Chapingo (Universidad Autónoma de Chapingo, UACh) where he began as professor in 1953, and from its Graduate School (Colegio de Postgraduados), where he taught until his death on February 21^st, 1991. To commemorate 100 years of his birth, the UACh's University Council agreed to declare "2013: The year of the Centenary of the Birth of Professor Efraím Hernández Xolocotzi"; this motto was captured on the institutional stationary during that year. Different commemorative academic activities were also carried out, where various current issues were addressed, as well as the perspective of the work by this outstanding professor. Another relevant action considered in the program of activities was the commemorative edition of the most renowned works by the Professor, selected by Xolocotzi himself for a first edition coordinated by Juan Pablo de Pina García, which would see the light as a special two-volume edition in the Agricultural Geography Journal, edited by the Autonomous University of Chapingo. Both the first volume, which appeared in 1985, and the second one that appeared in 1987, have been sold out for some time.

In the new commemorative edition of the Xolocotzia, which appeared on September, 2014, the editorial work was in charge of León Márquez Ortiz, who managed to exalt the presentation and design of the work, showing greater size, special inner design, and stylized decorative banners that refer to maize, as well as refined perspectives created by the great Mexican mural painter, Diego Rivera, at the Former Hacienda of Chapingo, México.

The 52 works contained in the new Xolocotzia-2014, although very relevant, only represent 12.2 % of the total of the Professor's work, which is measured at 425 printed studies (Cruz et al. 2013)³. The importance of Efraím Hernández Xolocotzi's written work lays not only in its extension, but rather in the diversity of subjects addressed and particularly in the depth and detail of the analysis, from different perspectives, of the complexity that small-scale agriculture and traditional technologies have, for which the Green Revolution did not have any socially viable options to offer. Currently these contributions, which are difficult to emulate, are seen as an important legacy for sciences like Botany, Geobotany, Agrostology, Agronomy, Education, Genetic Resources and Ethnosciences in general.

The Xolocotzia edition that comes to light now is still a valuable work, linked to current research and teaching in themes such as natural resources, Agronomy and Ethnosciences, particularly during this historical period when the divergence of industrial and traditional agriculture in the Third World is confirmed, a time that represents almost 25 years of considerable changes in society, economy and the Mexican countryside. The trend of development in agriculture described by Xolocotzi, confirmed and deepened every day, leads in the first place to the validity of the alternate paradigm of modern positive science, on the basis of traditional knowledge and technologies from buried cultures, which in essence protect the nationalist alternative in face of the repeated attempts by the Mexican State to implant the terminal phase of the "Green Revolution" model that depends on transnational businesses based on the homogenization of productive processes, around patents, transgenic products and agrichemicals, as the sole option for modernization of the national agricultural and livestock production, which from the start is structured based on the diversity of the temporal space of the environment, the genetic resources, and the productive processes of peoples.

The 52 works gathered in the two volumes of the Xolocotzia appeared in different publications previously; here they are grouped thematically and an initial autobiographical presentation of the author is offered, which accounts for the way in which the themes and approaches came about. Therefore, this presentation reflects to a large extent the evolution of the Xolocotzian thought.

The content of the work is presented grouped into five thematic sections, in each one of them the author makes a presentation and explains the objectives of some studies and in other cases he offers a review. Volume I presents 28 studies, of which there are nine in the Teaching subject, 14 documents in Agricultural Ecology, and the last five address themes referring to agricultural production. Volume II contains 24 studies grouped into Livestock Production and Germinal Plasm, each one of them with 12 different studies.

In the teaching section, five essential studies for agronomists and biologists are presented; these are: Apuntes para una clase de botánica económica, first published in 1955, this document according to the author ".. .marks the beginning of the effort to describe a field of study and research, dynamic, related to the use of our national resources. They have their basis on the guidelines of Harvard University's Botany School and develop towards what we now have established in our ethnobotanical approach."; Exploración etnobotánica y su metodología (1971), which refers to the delimitation and foundation of a methodology for the collection of phytogenetic resources and one of the agronomic works that presents outstanding literary characteristics, as a result of its narrative style; the content of the texts Metodología para el estudio de agroecosistemas con persistencia de la tecnología agrícola tradicional (1977) and Reflexiones sobre el concepto de agroecosistemas (1977), constitutes the conceptual basis of the studies about traditional agricultural technology, which seen from the perspective of the academic medium recognizes them as his most important contribution. Lastly, in this volume we find the study Los tipos de vegetación de México y su clasificación (1963) where Hernández X. participates as coauthor, with Faustino Miranda, a work of great importance for the Biology formation in undergraduate students. Because of its relevance in Botany, the CONABIO carried out a commemorative edition of this work in the year 2014.

In the case of the studies that refer to Agricultural Ecology, most of the fourteen documents presented arise from studies related to the Commission of Ecology Studies of Dioscorea in México, in addition to those carried out for the purpose of publishing in the compilations edited by Enrique Beltrán, and those that arose from the research done for students' theses, where the human factor of agriculture, the ecological nature of traditional agriculture, and the ethnobotanical approach to weeds are highlighted. In this section, the studies that stand out are: Graneros de maíz en México (1949), which is the equivalent to the Efraím Hernández X's Master's thesis, and one of the pioneering works in the theme that delves and contributes elements for later studies about traditional agricultural technology. Of similar importance, is the study: Las zonas agrícolas de México (1954), presented during the celebration of the Centenary of the National Agriculture School, in which the methodological bases for the agricultural zoning of the country were established, and where a regional approach is put into practice, which will be relevant for comparative agricultural studies and analysis of regional agriculture. Lastly, the article titled Sinecología de las selvas de Terminalia amazonia en la vertiente del golfo de México (1968), of which the principal author is José Sarukán K., should be highlighted from this group of texts, which initially appeared in Agrociencia Journal.

The last section of the first volume corresponds to the theme called Agricultural Production, where only five studies are presented, a sample of the different approaches explored by Professor Hernández X. in his agricultural studies. The oldest, titled La Agricultura en la Península de Yucatán (1959) is one of his initial works where a detailed description of production is achieved. The diagrams of agricultural diagrams are particularly interesting, to which he incorporates the daily record of precipitation, making it possible to appreciate the changes in frequency in the execution of agricultural tasks in function of the presence or absence of rain, maintaining the interest over understanding the dynamics of traditional agriculture. The last article of the section, called Agricultura tradicional y desarrollo (1980), could be the work that gathers the fundamental ideas about traditional agricultural technology and the need to foster its development even with contributions by modern agriculture, in as much as is prudent.

In this work Hernández X. starts from considering that technology reflects the way in which a society obtains its basic necessities, but which at the end have consequences that impact the development of communities. Thus, the criticism to the Green Revolution approach is presented in this document as a current contradiction in the following terms: "We are facing the task of achieving agricultural development in a population with social historical antecedents and philosophical bases that are different from a society whose developed agriculture we would like to use as a guideline for such development". This criticism, implicit in the aspiration of the approach predominant at the time, is followed by an increasingly more common approach that entails that, for community development: "...the best option is achieving a complementary conjunction between traditional agriculture and the contributions of agronomic sciences, based on self-management actions, where both the farmer and the professionals and institutions, play roles of mutual responsibility and respect". Efraím Hernández's work suggested an alternative to the one offered by the Green Revolution, and in fact, during the last years of his life, his research projects were in truth community development works, where he put into practice his approach for the development of traditional agriculture; such is the case of the Programa de Dinámica de la Milpa in Yucatán. Recently, a new impetus has been given to the revaluation of traditional knowledge and technologies reflected in quite diverse proposals in the scope of current Ethnosciences and the unfinished efforts of the regional agriculture group of today's Autonomous University of Chapingo, although they stand out because of the breadth of perspectives in the elaborations of Southern Epistemology and Knowledge Ecology by Boaventura de Sousa (2013)⁴ and works by Argueta et al., (2011)⁵ on Ethnosciences, among others.

In Volume II, the documents are grouped into two sections Livestock Production and Germinal Plasm. In the first one Agrostology works are included the specialization of Botany devoted to the study of grasses. As Hernández X. describes, studies in this subject began to respond to the educational needs of the ENA since 1954, and consisted in the intensive collection of grasses and, in 1957, with the support of a scholarship to study grasses at Harvard University, Xolocotzi travelled to the United States of America, where he revised the herbarium collections of this institution and then those at the National Herbarium in Washington, DC, and finally at the Missouri Botanical Garden's Herbarium. The information systematized by Hernández X. enriched the preparation of notes about the principal grass genera in México and the elaboration of identification keys for these plants, with which teaching in the Biology and Agronomy Schools was improved. During this stage of the Professor's professional development, he provided specialized advice to the Consultative Technical Commission for the Determination of Coefficients in Grasslands, and he performed research in the pasturelands of Chihuahua, Sonora, Durango and Zacatecas. The total of studies identified in Efraím Hernández's work in the Agrostology theme are around 40; the 12 included in Volume II of the Xolocotzia were published between 1957 and 1959, three in the 1960s, one in the 1970s and one in 1983, which signals some distancing from the theme; also, seven of the studies presented in the Xolocotzia were initially published in the journal Agricultrua Técnica en México.

For the section of Germinal Plasm, 251 pages of Volume II were included, making it the longest section, although it only contains 12 studies. We should also note that Professor Xolocotzi uses the concept of Germinal Plasm, instead of Phytogenetic Resources, and defines it as "...the set of genetic traits located in the hereditary mechanisms of organisms, favorable or potentially favorable to support production or to solve the problems of genetic improvement of organisms that produce a broad range of chemical basic necessities required by man". In the thematic presentation, he refers to the problem of the loss of interest over germinal plasm, accentuated as a result of the dominating idea in agriculture of obtaining maximum profit: "...which has led to undermine the very foundations of the whole conceptual structure of the use of improved cultivars, beginning to reduce the material necessary to face new epiphytes and new demands on production"; this same situation has led for the germplasm banks to increase their importance and for México to be recognized as an active center for domestication, of great ancestral wealth for germinal plasm since prehistory and until today. It ends with the desideratum that consists in becoming aware of the importance of germinal plasm, its incorporation to agricultural production for its strength and to foster its conservation; this task can be reinforced through traditional agriculture, where it also maintains its evolutionary dynamics. The content is covered mainly by studies with maize; of the 12 documents, seven refer to this plant, where the ones related to the study of maize cultivars and this cereal's variation stand out; it is important to note here that one of the tasks done by Efraím Hernández Xolocotzi was the collection of germplasm of Mesoamerican crops, to be deposited into the CIMMyT Germplasm Bank, but in particular he collected maize in México and in some other countries of Latin America. Of the remaining studies included, three are about bean and ayocote, one of the closest relatives to maize, and one more about an oleaginous palm of great importance. We also note here that the classical work on the description of maize cultivars is included, of which it is said that it is the book most often consulted in Agronomy: "Razas de maíz en México. Su origen, características y distribución". E. J. Wellhausen, L. M. Roberts, E. Hernández X. in collaboration with P. C. Mangelsdorf (1951).

The Bibliography of Efraím Hernández Xolocotzi is shown as the last part of Volume II, which is suggested by the editor as an element to go deeper into the study of the scientific and methodological basis upon which E. Hernández X. sustained the study of agriculture and its practical applications, since to the degree that greater questions are set out, delving into Xolocotzi's lifework becomes increasingly necessary. The bibliography presented includes the period from 1945 to 1985, and a total sum of 268 studies up to that moment. This number was updated by Cruz et al. (2013) to a total of 425 studies published, in a period that includes 50 years of professional life, from 1945 to 1995. It is obvious that works are included here which appeared after his death, in 1991.

At present, the marked limitations that the model of globalized development has shown to eliminate or decrease the great problems of hunger and poverty in humanity, and especially of traditional small-scale agriculture, which operates with a rationality different from the predominant one in large corporations and state-enterprises that bring us closer to a civilization crisis without return, moves to the front plane the urgency of delving and broadening the coverage of alternative studies such as the ones identified by E. Hernández Xolocotzi in traditional communities in México, also present in other parts of the world, as the sole option to think that development is possible without the increasing environmental and social crises.