Alejandra Nieto-Garibay

Automated Irrigation System Using a Wireless Sensor Network and GPRS Module

An automated irrigation system was developed to optimize water use for agricultural crops. The system has a distributed wireless network of soil-moisture and temperature sensors placed in the root zone of the plants. In addition, a gateway unit handles sensor information, triggers actuators, and transmits data to a web application. An algorithm was developed with threshold values of temperature and soil moisture that was programmed into a microcontroller-based gateway to control water quantity. The system was powered by photovoltaic panels and had a duplex communication link based on a cellular-Internet interface that allowed for data inspection and irrigation scheduling to be programmed through a web page. The automated system was tested in a sage crop field for 136 days and water savings of up to 90% compared with traditional irrigation practices of the agricultural zone were achieved. Three replicas of the automated system have been used successfully in other places for 18 months. Because of its energy autonomy and low cost, the system has the potential to be useful in water limited geographically isolated areas.

Preliminary compositional nutrient diagnosis norms for cowpea (Vigna unguiculata (L.) Walp.) grown on desert calcareous soil

This study calculated the compositional nutrient diagnosis (CND) norms of cowpea (Vigna unguiculata (L.) Walp.), as well as identified significant nutrient interactions of this crop growing in an irrigated calcareous desert soil. Three genotypes were distributed in rows in a 2-ha field. The soil showed high heterogeneity in its chemical properties. For statistical analysis, 86 foliar composite samples from healthy plants were used. Preliminary CND norms were developed using a cumulative variance ratio function and the χ2 distribution function. Means and standard deviations of row-centered log ratios VX of five nutrients (N, P, K, Ca, and Mg) and a filling value R, which included all nutrients not chemically analyzed. Preliminary CND norms are: VN*=0.174±0.095, VP*=−2.172±0.234, VK*=−0.007±0.267, VCa*=−0.022±0.146, VMg*=−1.710±0.132, and VR5*=3.728±0.084. These CND norms are associated with dry bean yields higher than 1.88 t ha−1, and are associated with the following foliar concentrations: 26.2 g N kg−1, 2.5 g P kg−1, 22.9 g K kg−1, 21.6 g Ca kg−1, and 4 g Mg kg−1. Cowpea plants growing in desert calcareous soils took up lower amounts of N, P, and K than those considered as optimum in a previous report. Six interactions were strongly indicated for cowpea through principal component analyses: positive for Ca–Mg, and negative for N–Ca, N–Mg, Ca–P, Mg–P, and K–P. Furthermore, two interactions were identified using simple correlations, negative N–P and positive K–Ca.

Differential responses of Chiltepin (Capsicum annuum var. glabriusculum) and Poblano (Capsicum annuum var. annuum) hot peppers to salinity at the plantlet stage

Poblano (Capsicum annuum var. annuum) and Chiltepin pepper (Capsicum annuum var. glabriusculum) are considered closely related parent species. Poblano pepper is a cultivated species that has lost stress tolerance attributes, and Chiltepin is a wild species adapted to adverse environmental conditions, such as salinity stress. Differential physiological responses between the wild and cultivated species were compared in order to study the physiological and biochemical mechanisms of Chiltepin’s salinity tolerance. Salt stress treatments were applied to Chiltepin and Poblano and their growth, chlorophyll content, transpiration rate, and concentrations of anions and cations in leaves, stem and roots were measured. Dry weight and relative growth index decreased significantly with salt stress in Poblano, chlorophyll-a decreased significantly in both peppers and transpiration decreased in Chiltepin, with no significant changes evidenced by Poblano. Concentrations of Na

Changing environmental conditions and applying organic fertilizers in Origanum vulgare L.

Any improvement in agricultural systems that results in higher production should also reduce negative environmental impacts and enhance sustainability. The aim of this research was to investigate the effect of two different production systems, one open-field and the other shade-enclosure with four bocashi doses, in order to find the best environmental option in terms of yield, physiological and morphometric characteristics in one oregano (Origanum vulgare L.) cultivar. In this study a completely randomized block design was used with four replications and evaluated for photosynthetic and transpiration rate, stomatal conductance, chlorophyll, leaf area and temperature, aerial and roots fresh and dry biomass, fresh and dry yield. The results showed that oregano adapted best to the shade-enclosure with increase yield of fresh and dry leaf weight of 165% and 118%, respectively, when compared to open-field. Also, higher doses of bocashi improved yield in both environments but more so in shade-enclosure. Soil moisture retention was higher in shade-enclosure which was reflected in physiological variables for soil matric potential, transpiration, stomatal conductivity, photosynthesis being significantly higher in shade-enclosure compared to open-field, thus improving yield. It seems that oregano plants can be grown and perform better under shade-enclosure than open-field and bocashi is a suitable organic fertilizer.

Baseline study of morphometric traits of wild Capsicum annuum growing near two biosphere reserves in the Peninsula of Baja California for future conservation management

BackgroundDespite the ecological and socioeconomic importance of wild Capsicum annuum L., few investigations have been carried out to study basic characteristics. The peninsula of Baja California has a unique characteristic that it provides a high degree of isolation for the development of unique highly diverse endemic populations. The objective of this study was to evaluate for the first time the growth type, associated vegetation, morphometric traits in plants, in fruits and mineral content of roots, stems and leaves of three wild populations of Capsicum in Baja California, Mexico, near biosphere reserves.ResultsThe results showed that the majority of plants of wild Capsicum annuum have a shrub growth type and were associated with communities consisting of 43 species of 20 families the most representative being Fabaceae, Cactaceae and Euphorbiaceae. Significant differences between populations were found in plant height, main stem diameter, beginning of canopy, leaf area, leaf average and maximum width, stems and roots dry weights. Coverage, leaf length and dry weight did not show differences. Potassium, sodium and zinc showed significant differences between populations in their roots, stems and leaves, while magnesium and manganese showed significant differences only in roots and stems, iron in stems and leaves, calcium in roots and leaves and phosphorus did not show differences. Average fruit weight, length, 100 fruits dry weight, 100 fruits pulp dry weight and pulp/seeds ratio showed significant differences between populations, while fruit number, average fruit fresh weight, peduncle length, fruit width, seeds per fruit and seed dry weight, did not show differences.ConclusionsWe concluded that this study of traits of wild Capsicum, provides useful information of morphometric variation between wild populations that will be of value for future decision processes involved in the management and preservation of germplasm and genetic resources.

Environmental traditional knowledge in a natural protected area as the basis for management and conservation policies

Ethnobotany is an adequate tool to identify the most import wild edible plants used by local people and to develop strategies for its sustainable use and policy making. This research records the wild edible plants used by the inhabitants of the Sierra la Laguna Biosphere Reserve, in Mexico, and identified priority species for sustainable development. The employed quantitative approach included the application of a food-oriented index named Food Significance Index (FSI), which integrated cultural, agricultural and food parameters; moreover, it used multivariate analysis to identify priority edible species for use and/or conservation. Fifty taxa were identified as the most important wild edible plants in the reserve, integrated into five priority groups. Foods in priority group 1 had the highest culinary diversity by grouping three fruits (Ficus petiolaris, Stenocereus thurberi, and Cyrtocarpa edulis), one almond-like seed (Cnidoscolus maculatus), one vegetable (Matelea cordifolia), and one condiment (Capsicum annuum). Priority groups 2-5 were selective for one or two types of food, such as fruits, teas, or seeds. Since group 1 was the most diverse, the FSI and the employed strategy permitted to identify the priority wild edible plant species with the highest potential for food security. The selected six species should be included in the future management program of the reserve as the priority wild edible plants to develop strategies for conservation, sustainable use, and improvement of the local population income. General policies to manage the selected six species are outlined.

Ecology and Adaptation of Legumes Crops

In this work we present and discuss some of the advances reached in relation to environmental crop management and adaptation to warming climates of legume crops, frequently associated to plant breeding, towards drought tolerance. At the same time, the benefits related to the contribution to the development of an appropriate legumes-based agriculture for arid zones are analyzed. The Leguminosae and Gramineae families are by far the world’s most important sources of food. Legumes include beans, soybeans, peas, alfalfa, and other crops, which supply protein fats, fiber and wood. Through their root nodules, inhabited by Rhizobium bacteria, the legumes also improve the nitrogen balance in the soil. Legumes comprise one of the largest plant families in the world, with near 18,000 species. Most species are tropical and include trees, woody vines, and herbaceous plants. All legume plants bear pods or legumes, which are diversely modified within the family. Most have compound leaves. As regards to warming climates under the effects of climate change, drought is defined as any period during which water deficits in the plant or agroecosystem affect growth and development; in this sense, the duration of drought determines the quantity of damage caused to crops. Two reasons are analyzed to develop programs of breeding and management directed to drought tolerance by means of an environmental understanding and ecophysiological selection of plants, according to their interactions with the environment: The first one is to maximize the productivity and consistently the plant performance, stabilizing or increasing productivity. The second one is to improve the drought tolerance; under this consideration the mechanisms of water conservation, constitute for the plants an important option to survive a drought, although they tend to limit their productive potential. It is concluded that an appropriate ecological management of crops and the ecophysiological selection can constitute a feasible way for agricultural sustainability.