Introduction

Creole maize seeds are sown in most of the agricultural surface of Estado de México (^{Herrera et al., 2002}), and they belong to five races for this region (^{Wellhausen et al., 1951}). The management of crops by peasants has increased the diversity of varieties, conserving the identity and the genetic variability in the form of local populations. The traditional selection practiced has improved (yield or quality), however, when visually selecting based on the properties of the corncob, the height of the plant is put aside. It is unknown whether the corncob was from a cuatera plant or not, or one with stem lodging, root anchoring, and number of plants with feminine infertility; an increase in the value of some of these variables is related to a decrease in their yield potential (^{Niño et al., 1988}).

In maize (Zea mays L.) cultivation milpas, the genotypes that represent it exhibit different degrees of variation, product of the selection by man and the environment in relation to the ecological, physiological, culinary pressure, and the peasants' worldview (^{Hernández, 1972}). The peasants were identified by having a family economy; they are small-scale producers with land, they farm with the help of simple equipment, and family work produces for their own consumption. They are also characterized by being farmers and livestock producers; they identify as a group, which shares socioeconomic and cultural aspects. Mainly, the peasant unit is devoted to cultivating for dietary sustenance (^{Chayanov, 1974}; ^{Wolf, 1975}; ^{Martínez, 1985}). "...the peasant to produce has to invest his work and his family's, use his land, his own beasts of burden, uses his mental strength to plan and manage, uses seeds from his crops, has to plan yields not just to survive biologically, he and his family, but it has to be enough to feed his workforce, animal traction, and perhaps fatten up some animals for their festive consumption. He must decide whether to use or not some agrichemicals (fertilizers, insecticides, herbicides, etc.). To obtain products such as grains, fodders, fibers, animals or their byproducts, in addition to some useful byproducts for his domestic unit or that get profits in the market..." (^{Martínez, 1985}). The peasants have maintained the conservation and improvement of their seed generation to generation.

Within this context, phylogenetic resources must be treasured in order to be used (^{ONU-FAO, 1996}); the greatest part of the native maize genetic diversity in México can be found in the agricultural fields in the form of Creole varieties (^{Wellhausen et al., 1951}), since only 18.8 % of the surface sown with maize uses improved seed (^{USDA-SAGAR, 1997}); evolution is a continuous fact, since the peasants continue to identify additional characteristics and to combine genetic materials, contributing their ingenuity to form more cultivars; and the conservation of these genetic resources in situ is a daily activity.

The contributions made by ^{Hernández X. (1980)}, relative to the selection and conservation of seeds, were taken into account. The objective of the research was to analyze the proportion of farmers who use Creole or improved maize seed in the community of study, located in Valle de Acambay, a zone with homogenous conditions; and to understand the percentage of peasants who use Creole seed, the physical characteristics of the corncob that the peasant takes into account when performing the selection, the moment when he does it, and the corncob that he uses. Also, to describe the experience accumulated by peasants in the selection of Creole seed.

Materials and Methods

The study was carried out in the community of Pueblo Nuevo, Valle de Acambay, Estado de México, where traditional agriculture is practiced directed at family auto-supply, rather than the market. The workforce is familiar and they use few external inputs; the production is destined to auto-supply and their subsistence is based on a combination of agricultural practices and paid work (^{Hernández X., 1972}; ^{Toledo, 1990}). It is a community representative of the rural zones in México, scarcely integrated to the market economy, where Otomí is spoken, and there is a high degree of marginalization. The physiographic characteristics are Feozem type soil in more than 50 % of the plots and, to a lesser degree, Vertisol. There is a forest of common use; droughts and sometimes frosts are frequent in the community and the region, generating for the agricultural/livestock production conditions to be limited, according to the information from the Municipal Land Registry.

The field phase to gather information was carried out during autumn of 2014, and the daily activities of the peasant and his family were taken into account. The qualitative approach is based on the fundamental idea of observation and description of participants within a community; they serve to study rural development from a descriptive point of view (^{Hernández et al. 2005}; ^{Geilfus, 2002}). A field visit was carried out, an exploratory study, and a visit to perform surveys with peasants from the place, applied in their private address, which is where they are more easily found, and the interview can be performed effectively. The problem and the research tools were established from the information obtained.

The exploratory phase and the interviews with key informants was carried out to understand the following characteristics: peasant profile, resource evaluation, flow diagram of activities in maize cultivation, budget for the cultivation, problems in seed storage, and planning of self-diagnosis of local solutions. The exploratory study allowed concluding that the peasant families present homogenous characteristics in terms of the practices of seed selection and productive tasks. The study method used was descriptive; a simple random sample was carried out, where all the peasant families were considered. In the quantitative methodology, work was performed with the questionnaire supported by statistical methodology, using the research variables (^{Hernández et al., 2005}).

The population is the peasant families (heads of households). There are a total of 710 households. Because the population is quite homogenous, it was determined that the size of the sample could be 50 peasant families. In this case, all the peasants are proposed for the analysis and have the same probability to be selected. The sample is more than 5 % of the population and is sufficient due to the similar characteristics of peasant families. The survey design allowed recording the information, taking into account the study object and the variables selected. The questionnaire was made up of 46 questions, closed, multiple option, and some open ones to facilitate their application and enrich the information. The data obtained were analyzed with descriptive statistics (^{Infante and Zárate, 2005}), using the Excel software version 2010 (graphs, averages, frequencies). The qualitative information was obtained by performing visits to the plots and with participant observation (^{Geilfus, 2002}). At the end, supported by the characteristics of traditional agriculture, this leads to analyzing and understanding the information gathered (^{Hernández, 1972}; ^{Toledo, 1995}).

With the anthropocentric approach, and taking as a basis that maize agriculture generates interdependency between the environment and man (^{Hernández X., 1949)}, we proceeded to determine the proportion of peasants who use Creole or improved seed; then, to observe at what moment of the productive process the selection and conservation of the seed and its maize cultivars begins. Finally, the main features that the peasant considers when selecting the seed (size and health of the corncob, among others), and which part of the corncob is used for seed, were quantified.

The seed reproduced in the community since at least 30 years ago was considered as the Creole variety (^{Louette and Smale, 1996}); as a variety foreign to the Creole, which was acquired through a peasant from a different region in recent times; and as commercial, the one that comes from an improved variety.

Results and Discussion

Based on field visits (participant observation), it can be said that the community of study has a disperse settlement pattern; there is no defined street grid and there is scarce space for vehicle transit. Only the main road is paved and connects towards the northeast with the municipal township, and towards the southeast with the communities of Bocto and San Mateo. The streets are well-defined, covered with cement and some stretches with rocks, as well as with red tezontle and stone pavement. To the northwest there are schools, the church, the health center, and the market. In terms of agricultural activity, maize cultivation is practiced in more than 80 % of the plots (autumn, 2014); there are some empty lots, and there are fruit trees, flowers and medicinal plants in the backyards. Most of the harvest of the products that the population cultivates is destined to auto-consumption, and feeding poultry and small-scale livestock.

General aspects of seed cultivation, selection and storage

In México, the area cultivated with maize (80 %) is sown with Creole seed (^{USDA-SAGAR, 1997}) and in the community of study it constitutes 100 % of the maize cultivated. According to the peasants surveyed, regularly the emergence of the seed cultivated in milpas is affected by various adverse factors: embryo death in the seed (38 %), lack of water (32 %), bad preparation of the land (10 %), pests present in the soil (6 %), the sower throwing the seed outside the area (4 %), the seed being covered (2 %), the seed being too small (2 %), lack of health (2 %), and other factors (4 %).

The peasants in the zone of Valle de Acambay use agrichemicals; most apply fertilizers and herbicides, performing one to two applications of the liquid per cycle (84 %). Others only apply fertilizers (12l%), and the rest do not use agrichemicals (they eliminate weeds with the use of tools like the hoe), and carry out fertilization with organic fertilizer (4%). They grow maize (98 %) and tomato (Solanum lycopersicum) (2 %), of which 14 % plant it in association or interspersed with another crop: wheat (Triticum aestivum L.), bean (Phaseolus vulgaris L.), broad bean (Vicia faba var. equina), squash (Cucurbita moschata, Potret) or oats (Avena sativa L.). The average maize yield (in monocrop) is 1.9 t/ha and 1.6 t/ha (interspersed maize). The seed selection technique is from seed inherited by peasant family members (96 %), help from neighbors (2 %), and others (2 %). Seed selection is done as a family, with the participation of their spouse and children (80 %) and the help of relatives (12 %), day laborers (4 %), friends (2 %), and others (2 %).

The peasants cultivate mainly white maize (40 %), white mixed with other colors (20 %), white or blue (12 %), white or black (10 %), white or pinto (8 %), pink (6 %), pinto (2 %), red (2 %). The cultivation of maize with colors different than white is carried out in smaller plots, in the case of the peasants who have more than one plot, or in some furrows of the milpa, since they use it to make tortillas for the patron saint's or family festivities. The type of maize more often cultivated in the community and according to the opinion of peasants is white, since when there is a surplus it is easy to commercialize.

The seed is stored in a closed barrel (46 %), in attics (36 %), in a different part of the household (10 %), or in the barn (8 %). The seed is packaged in fiber sacks (76 %), in barrels (16 %), containers (4o%), and some do not package it (in bulk, 2 %).

When a peasant does not have seed or it is not enough for their sowing, they purchase it or exchange it for maize between neighbor peasants or they get it from family members. The seed or grain is dried on the rooftop (74 %), the home patio (18 %), and in the attic or the kitchen (2 %). They clean their seed, winnow it (62 %) using the wind (36 %) or leave it in a room (2 %).

All the peasants surveyed use Creole seed (100 %) and they select it, in addition to keeping it in their properties since three generations ago. The type of seed used is associated to the type of agriculture in each region (^{Louette and Smale, 1996}). In the community, a type of peasant agriculture is practiced, which sustained by a selection process under domestication of the genetic resources (seeds-Creole); it is an empirical experience, physical-biotic knowledge, an informal education to transmit the knowledge, and a cultural heritage in the mind of the peasant community (^{Hernández X., 1972}; ^{Toledo, 1990}). On the other hand, the regions that practice entrepreneurial agriculture lean on their use of pesticides, fertilizers, machinery, improved seed, etc., backed up by the use of irrigation, market vision and high energy consumption (^{CEPAL, 1986}; ^{Toledo, 1995}).

Most of the peasants carry out seed selection (after cleaning the corncobs), after the harvest (91 o%); others prefer to do it before (4 %). The selection carried out by man throughout the centuries made it possible to have the current maize varieties; the seed selection after the harvest has the disadvantage of not knowing if the characteristics selected are due to the environment where it developed, if the plant had competition where the seed was obtained, or if the corncob from which it was obtained is due to the genotype of the variety. In general, it is characterized by a variable degree of heterogeneity inside the population, relative to traits like health, plant height, precocity and productivity, among others (^{Louette and Smale, 1996}).

Only 4 % of the peasants mentioned selecting their seed before and after the agricultural cycle (pre-selection), when harvesting previously marked corncobs. Those who use this variant are the ones who have forms or types of maize with particular traits (plant height and size of the corncob), identifiable in the study region.

The percentage (under 10 %) of peasants who perform maize seed selection from purchased varieties mention that the introduced varieties that manage to produce well are selected by the producer based on specific characteristics (good anchoring, plant height, size of the corncob); after, they are adopted and exchanged among themselves. The main factors that explain seed exchange among the community are: momentary seed availability, agricultural calendar, and peasants' curiosity (^{Louette, 1996}). In the community of study the common practice is resorting to getting local seed with peasant neighbors when, for any reason, they are left without seeds, or else, when they want to cultivate maize of a different color than white, since it is used with less frequency.

The introduction of a variety has an effect on the genetic structure of the local varieties, in function of the distance between plots (^{Hainzelin, 1988}), time between flowering (^{Bassetti and Westgate, 1993}), and pollen concentration in the air (^{Raynor et al., 1972}), among others, since the peasants do not seek isolation in space or reproduction between varieties (^{Louette, 1996}).

The characteristics that peasants take into account to select their seed are size of the corncob (70 %), corncobs with thin stalk (18 %), health of the corncob (8 %), a different color (4 %).

The identification performed by peasants of the size of the corncob as main characteristic is in relation to the conditions of rainfed agriculture that is practiced, which requires sowing at a greater depth and, therefore, requires seed with higher reserve content to emerge. The selection pressure on one characteristic can be an indicator of how the selection carried out by the peasant generates diversity in maize varieties in one region. From this, we find that there are races of large corncob, large grain, many rows, good corncob coverage, thin stalk, among others, and variation between these distinctive characteristics. In the community the peasants choose large corncobs, their grains of greater size, in addition to the fact that they cultivate other colors of maize different from white, to a lesser degree, which fosters greater diversity of the local maize.

This type of peasants plays an important role in the conservation and generation of maize diversity in situ, since with daily activity they identify additional characteristics (plant with good foliage, vigor and anchoring); combined in a creative way, in harmony with the corncobs, the plants maintain and create greater variation. Likewise, it is likely that some recombinations have greater genetic stability as consequence of continuous selection. In this regard, selection under domestication has a direct relationship with the ways in which rural communities use maize (^{Hernández X., 1972}).

Once the corncob from which the seeds are obtained is selected, the results allow affirming that more than half of the peasants use only the central part of the corncob (70 %), together with those who choose from the basal part (26 %) and from the whole corncob (4 %), responding to particular conditions, such as having an irrigation system at the time of sowing, having had a difficult year in the prior cycle and not having enough seed for the next sowing. From what was mentioned before, it is reported that a total of 96 % of the peasants do not use the smallest grains of the corncob. This situation makes evident their preference for the seed of greater size and uniformity, when choosing grains in the central and basal part of the corncob because they expect to obtain in their crops a higher number of seedlings that are more vigorous. It is particularly important in rainfed areas where the moisture conditions at the time of sowing are not always favorable; the seed is deposited at a greater depth in order to be in contact with the moist soil, reason why it requires a greater reserve to emerge.

The application of the prior characteristics as selection criteria allows the peasant to obtain seed of good physical, physiological and sanitary quality, since when selecting the central part of the corncob with greater size (healthy, thin stalk) he obtains seed with certain uniformity, free of pests and diseases, contributing to obtaining greater vigor and germination.

The phenotypical variety of maize that predominates in Valle de Acambay corresponds to the conical type, which has an acceptable yield; its highest adaptability to the valley will contribute to deriving precocious populations of higher yield. Crossing this Creole (conical) variety with other maize hybrids, as a principle for genetic improvement, could be useful to decrease the height of the plant, lodging and sterility.

The technique for seed selection that peasants carry out is acceptable, although they could add some measures: performing the selection practice before, during and after the harvest, with which it is possible to identify healthy plants (strong stems, plant height and ideal corncob, filled and large, among others). This would allow through time to develop a maize type or variety that adjusts to their preferences in an integral manner.

Economic aspects

In the question regarding other sources of income of the peasants surveyed, the research resulted in the following data. They obtain from agriculture their main income (36 %); likewise, they practice trade (28 %), another activity (14 %), livestock production (8 %), are day laborers (8 %), employees (4 %), and agriculture and livestock (2 %).

Among the activities most of the family income comes from, there are: handcrafts sales (36 %), agriculture (24 %), commerce (18 %), livestock production (12 %), remittances (4 %), government program (4 %), other (2 %).

Conclusions

The use of seed is associated to the traditional agricultural system. Most of the peasants in the region carry out the seed selection when the corncob is already formed, choosing that of greatest uniformity, greater size, and free of pests and diseases. One of the relevant aspects that peasants consider is the corncob health, which is of vital importance to obtain better germination of the seed.

Peasants in the study zone cultivate Creole maize of conical type in rainfed environments; they select the seed after the harvest, seeking seed that comes from a corncob that stands out for its size, thin stalk, and shows the best health; they choose from the central and basal part of the corncob.

The peasants of the place have the self-management capacity of selecting seed from their own, without depending on seed companies, which allows having a wealth of varieties of different colors of maize and favorable conditions for precocity, and adapted to the climate conditions of the community to obtain an acceptable production.