Study area

The study was performed in the grape-producing area of Aguascalientes, which includes seven municipalities: El Llano, Cosío, Rincón de Romos, Asientos, Tepezalá, Pabellón de Arteaga and San Francisco de los Romo (Figure 1). The area is located at altitudes of 1700 to 2400 masl; the climate is semi-dry, with an annual mean precipitation of 400 to 450 mm in the municipalities of Cosío and Tepezalá, and of 450 to 500 mm en El Llano, Rincón de Romos and Pabellón de Arteaga. The annual mean temperature is 16 to 17 °C and the soils are characterized by presenting medium textures that allow the easy penetration of roots and have a medium capacity for moisture retention (^{Maciel Pérez et al., 2005}; ^{INIFAP, 2013}).

Figure 1 Study area in the grape producing region of Aguascalientes. 

Characteristics of the producers

Results from the survey indicate that 98 % of producers were men of ages that range from 23 to 81 years. The average age of producers was 59 years old, well above the average age for the state in 2010, which was 24 years (^{INEGI, 2010a}; ^{INEGI, 2010b}); 54 % of producers had primary education, 22 % secondary, 10 % high school, 12 % have university education and 2 % do not have studies. Table 3 shows that producers had 7.8 school years; when taking into account that in 2010, 16 % of the population of the state had primary education and 22.5 % secondary (^{INEGI, 2010c}), it can be said that schooling in vine producers is low. ^{Damián Huato et al. (2007)}, ^{Velasco Fuenmayor et al. (2009)} and ^{Vélez Izquierdo (2012)}, point out that both variables are factors that influence directly the way of cultivating and the willingness to adopt new technologies. Producers said that they had 20 years of experience in grape production, in average, although 34 % were located within a range of 1 to 10 years; 18 % from 11 to 20 years; and 48 % from 21 to 40 years.

Table 3 Sociodemographic characteristics of grapevine growers in Aguascalientes. 

Source: elaborated with information obtained in the field during 2013.

The average surface planted by producers surveyed was 4.8 ha, although the most frequent size of the plot is 2 ha. Data from the Consejo de Viticultores de Aguascalientes A.D. indicate that 95 % of the producers have their vineyard on ejido lands with a plot size of up to 5 ha, while the other 5 % are vineyard producers with 6 to 143 ha in lands under the regime of smallholding. Land ownership marks differences in the management of the crop and the technology employed. Smallholding observed a larger surface planted with grape and greater diversification of varieties destined to industry, table and wine production; in addition, they use different management practices such as grafting, they have knowledge about pest and disease control, fertilization, drip irrigation, and give added value to the product with the industrialization and elaboration of products derived from grape. In turn, the ejido sector shows a trend in the production of two varieties, the Salvador and Red Globe grapes; their management practices are not as technified and the use of graft-holders and establishment of drip irrigation systems is incipient.

In addition to grapevine cultivation, 58.7 % of the producers complement their income with other crops such as maize and bean; 19.6 % with livestock production activities; 10.9 % with income from a second job; and 10.8 % with a business of their own.

Crop management

^{Fernández Alcázar (2011)} points out that each vineyard presents a particular way of managing the crop, which depends on several factors, such as size of the plot, plant formation system, age of the plantation, machinery, localization and available workforce, among other variables; therefore, a model based on the tasks that are mainly performed in the vineyard should be established. In Aguascalientes, the activities in the vineyards begin at the end of January, with preparation of the land that depends on the type of irrigation; 55 % of the surface planted with grapevine has gravity based irrigation in furrows and through streets, and 45 % uses drip irrigation. In the gravity based irrigation system, before each irrigation event, furrowing is done, and then dragging to eliminate weeds and conserve moisture in the terrain. In the drip irrigation system, only dragging is performed, to eliminate weeds mechanically.

Of the producers surveyed, 98 % use vine shoots as vegetative propagation material; only 8b% indicated that they also use cuttings and grafted plant, primarily, for the Salvador varieties on the graft-holder 1113 and Red Globe on Rupestre. The use of graft-holders in the Aguascalientes vineyards is low, even when the importance of their use has been highlighted, as well as the advantages generated by a decrease in problems with pests and diseases, the contribution in the adaptation of grapevines to soils with different physical and chemical characteristics, problems of excess or lack of moisture, compacted soils, of low fertility and with problems with salts; likewise, it represents a way of non-chemical control, less damaging to the environment (^{INIFAP, 1998}; ^{Muñoz and González, 1999}). According to Según ^{Márquez Cervantes et al. (2007)}, the use of graft-holders contributes to fruit production with lower irrigation water demand and improves the quality of the grape under a scheme of innocuousness and sustainability. In face of this outlook, it is important to guide the producers, primarily to those in the ejido sector, in the use of graft-holders in their vineyards.

The average density of vines in the vineyards was 2660 plants per hectare of the Salvador variety and 2339 of the Red Globe variety. It was observed that the grapevines are planted at an average distance of 1.3 between them, and the distance between rows was 3.0 m. The system of vineyard conduction is different depending on the grape variety. For Salvador, the system used is bilateral conduction between two benches, the first bench at a height of 0.7 m and the second at 1.4 m. For Red Globe, the system of conduction is to one bench and it is established at a meter of height. ^{Aliquó et al. (2010)} points out that there are many types of pruning, although, in general, there are three principal ones: short, mixed and long. The name of the type of pruning depends on the length of the vine shoot and the number of buds that the pruner leaves behind. In the case of vine producers in the state, mixed and short pruning is practiced; the producers of Salvador grape leave vine shoots of between 15 to 50 cm on the vine, with 12 loaders and 18 buds, while for the table grape the length of the vine shoot is between 5 and 40 cm long, with 8 loaders and 14 buds. Both the type of conduction and the pruning of grapevines are cultural practices that modify the production of grape and its quality (^{Walteros et al., 2012}). ^{Aliquó et al. (2010)} mention that the pruning systems are not applied interchangeably, but rather that each vine has its own demands in function of the location of the fructifying buds; from there, the importance of determining the number of buds that are left on the grapevine.

Of the producers, 65 % pointed out that they apply bovine manure to fertilize the vineyard and the amount of organic material ranges between 3 and 15bt per year for both varieties. Concerning the chemical fertilization in table grape, the most common N-P-K treatment is Triple 17 and urea; on the leaves, they apply sulfur. In the Salvador grape, they apply urea, soil salt (combination of nitrate and phosphorus), and Triple 16 and 17, as well as boron, zinc and sulfur on the leaves. The weeding of the vineyard is done manually with mattock and only 12b% of the producers applied any type of herbicide. Pest and disease control is done chemically. In 2012, the most damaging pests that attacked the vineyards were the following: Western grapeleaf skeletonizer Harrisinia brillians Barnes and McDunnough, thrips Frankliniella sp, plant louse Aphis illinoisensis (Shimer) and leafhopper Erythroneura spp. ^{González Gaona et al. (2014)} mention the presence of other pests such as vine shoot screw-worm Micropate labialis Lesne and Frailecillo beetle Macrodactylus spp. The producers point out that the most important pests were powdery mildew Oidium spp, dead arm of grapevine Eutipa armeniacae Hansf & Carter, Texas root rot Phymatotrichum omnivorum (Shear) Dug, corky bark-rugose wood (viral complex) and mildew Plasmopara vitícola (Berk and Curt). ^{Velázquez Valle et al. (2013)} indicate that there are other diseases of viral origin that affect the vineyards in Aguascalientes, such as the Grapevine leafroll-associated virus GLRaV and the Grape fanleaf virus, GFLV.

Table 4 presents the estimated technological index for the two types of grape. The results indicate that in the production of table grape, a higher level of technology is used, mainly because it is a product in which the quality of the fruit must be taken care of; for this purpose, the grapevines require a better preparation of the terrain, higher fertilization, particularly foliar, and greater pest and disease control.

Table 4 Technological level used in the production of Salvador and Red Globe grape in Aguascalientes. 

Source: elaborated with information obtained in the field during 2013.

Fruit harvesting is done from August to September; cutting of the Salvador grape is determined by the maturity and the Brix degrees of the fruit. Producers point out that the grape can be harvested when it has 17 Brix degrees minimum, although the ideal is 20 to 22 degrees; the degree of sweetness of the fruit also influences the price paid to the producer. In the case of the table grape, the harvest depends on the degree of maturity of the fruit; only 18 % of the producers mentioned that they perform the selection and packing of the fruit themselves, since these activities are usually performed by intermediaries.

Commercialization of the grape for industry is carried out wholesale, and 80 % of the production is absorbed by the juice and concentrate industry present in the state (^{SEDRAE, 2014}). The table grape is sold in the state’s local markets and distributed to other cities like Guadalajara, Monterrey and Zacatecas.

Production costs

Table 5 shows the production costs for the Salvador and Red Globe varieties, under the modalities of gravity based and drip irrigation. The production costs for the Salvador variety with the gravity based irrigation system were calculated at 36 270 $ ha^-1, and 33 990 $ ha^-1 for the drip irrigation system. For Red Globe, the production costs with gravity based irrigation were 40 843 and 37 562 $ ha^-1 with drip irrigation. Manual labor represents the highest cost, followed by inputs for production, indirect costs and mechanized tasks. This structure of costs is similar to the one estimated by ^{Torres Álvarez (2013)}, where manual labor represents the highest percentage of production costs, because grape demands a large amount of labor due to the care that must be used with the fruit.

Table 5 Production costs of Salvador and Red Globe grape varieties per type of irrigation (Pesos per ha). 

Source: elaborated with information obtained in the field during 2013.

Table 6 shows the number of times that each cultivation task is performed in the vineyard, and the workdays required for each occasion. Grapevine is an intensive crop in terms of labor, primarily for some cultivation practices such as formation pruning, weeding and fruit harvesting. According to the field data, an average of 130 workdays was estimated per ha in each agricultural cycle.

Table 6 Number of cultivation practices and workdays used in the vineyards of Aguascalientes. 

Source: elaborated with information obtained in the field during 2013.

Profitability analysis

The average yield in the Salvador grape production in the gravity based irrigation system was 16.3 t ha^-1, and it was 17.8 t ha^-1 in the drip irrigation system, while the Red Globe grape had an average yield in gravity based irrigation of 14.6 t ha^-1and in drip irrigation, 15 t ha^-1. The sales price obtained by the producer was 3700 $ t^-1 for the Salvador grape and 8000 $ t^-1 for Red Globe.

Table 7 shows the investment per ha, the income and the profit, taking into account the yields per ha for each irrigation system and variety, the sales prices for producers, and the cost-benefit relationship. Profitability in the production of Salvador grape was 24 040 and 31 870 $ ha^-1 in the gravity based and drip irrigation systems, respectively, while profitability in the Red Globe grape production destined to the fresh market was significantly higher (75 957 and 82 438 $ ha^-1). This difference is due to the higher price of the table grape (2.16 times higher than the price paid by industry), since the production costs were higher for the Red Globe grape.

Table 7 Profitability of grape for the industry and for fresh consumption in Aguascalientes. 

Source: elaborated with information obtained in the field during 2013.

The cost-benefit relationship was higher than one and was between 1.7 and 3.2, which indicates that grapevine is profitable in all the production systems. The CBR indicates that for each peso invested in the production of Salvador grape, 80 cents of net profit are obtained in average. Similarly, for each peso invested in the production of Red Globe grape, an average net utility of 2.0 pesos is obtained. This result indicates that the table grape is more profitable compared to the production of grape destined to the industry.

It is also observed that the CBR is lower in the gravity based irrigation systems for the Salvador grape (1.7 vs. 1.9), and for Red Globe (2.9 vs. 3.2), indicating that drip irrigation is more profitable because of the decrease in costs from mechanized tasks (furrowing), and the savings in workforce for some activities like pruning. The difference in profitability sets the standard to conclude that there is a need to make production systems that use gravity based irrigation more efficient, through programs of technological innovation and the development of new capacities for producers in the use of new technologies that allow them to increase their yields at a better cost. In addition, caring for the environment should be emphasized through practices that imply saving water.

It is important to foster scientific research that supports the production and post-harvest management of the grape. Organization between grape producers must also be promoted, to gain access to credit, more affordable input prices, and mechanisms that ease commercialization. There should be support with training for product processing, and access to information about markets and prices.

An important factor that influences the crop’s profitability is the behavior of prices. Data from ^{SIACON-SIAP (2012)} indicate that during 2002- 2013, the real prices of grape for industry and for fresh consumption in Aguascalientes showed a mean annual growth of 7.9 and 12.8 %, respectively, compared to the growth rate for real grape prices at the national level (14.3 and 1.8 %). It was observed that grape prices for industry in Aguascalientes had a lesser increase than nationally. These data indicate that the real grape prices that Aguascalientes producers receive have not grown in the same proportion as the national ones.