The pecan tree is one of the most cultivated fruit trees in Mexico because of its high profitability. This fruit needs significant amounts of zinc (Zn), which ranks as one of the micronutrients most required by this crop. The main effects of Zn in plant metabolism are observed in the synthesis of chlorophyll and tryptophan. It is also involved in enzyme activity related to the detoxification of reactive oxygen species. This nutrient deficiency is related to soil type. In order to understand the factors that influence zinc bioavailability in soil for pecan tree nutrition, the following review is presented. It is concluded that Zn deficiency in pecan orchards is more common in cold weather periods, wet springs, sandy soils with low organic matter content, alkaline pH and high levels of carbonates. This deficiency causes poor root development.

Samplings of insects associated with huizache were carried out from March to September 2013 in ten huizache trees located at Chapingo Autonomous University’s Drylands Regional University Unit (URUZA), located in Bermejillo, Dgo. A motorized D-Vac model 2846 vacuum insect collector and yellow sticky traps were used. The collected material was reviewed under a microscope in the laboratory, finding mostly homopteran insects, particularly adult whiteflies and two groups of parasitoids. The whitefly species affecting huizache was identified as Tetraleurodes acaciae (Quaintance) (Homoptera: Aleyrodidae). The population dynamics of this homopteran was recorded based on adults collected in 20 cm2 yellow sticky traps, with the highest incidence being recorded on July 29 with 359 adults. Percentage parasitism in nymphs was estimated by sampling date, under controlled temperature (28 °C) and relative humidity (30 %) conditions. After 72 hours, emergence was determined, identifying the parasitoids Eretmocerus sp. (Hymenoptera: Aphelinidae) and Signiphora sp. (Hymenoptera: Signiphoridae). The combined percentage parasitism ranged from 0-62 %, with the highest percentage being recorded on September 12. Of the total number of adult parasitoids, 199 individuals belonged to Eretmocerus sp., accounting for 67.2 % of the total, and 97 to Signiphora sp. (32.8 %). This is the first time that the whitefly T. acaciae has been recorded in huizache in Mexico. Likewise, this is the first verified report of the two identified parasitoids in huizache in Durango, and in the whitefly T. acaciae.

A method to analyze climate variability and quantify its impact on bean yield under regionalized climate change scenarios is proposed. The algorithm consists of four steps: a) identification of agricultural land sown with bean, b) obtaining of climate parameters that define the region and use of a stochastic generator (LARS-WG) to obtain regionalized climate change scenarios; c) the matrices that define the climate conditions at the site are embedded into a crop model (EPIC) to assess the impact on crop yield and d) a spatial distribution of the information is performed. The results indicate that under future climate change scenarios (A2 and A1B), yield increases in the range of 0.1 t·ha-1 are expected in some areas, along with decreases of 0.2 t·ha-1 in others. Increases in maximum and minimum temperature, as well as increases and decreases in rainfall, are also foreseen for some areas of the state. Based on the proposed method and the expected future changes in climate patterns, it would be advisable to perform simulation runs considering adjustments in management practices to compute the reduction in climate risk to agricultural areas.

The demand for information on carbon transport led to the generation of data on the output of organic carbon in soil particles in suspension. Different land uses were considered: buffelgrass pasture (BGP), abandoned farmland (AFL) and native rangeland (NR). The rainfall simulation technique was used to generate runoff on runoff plots (3 x 1 m) in order to obtain in each land use a 0.5-liter aliquot, from which the solid sediments (soil and organic material) were separated and the carbon percentage determined by the Walkley & Black analysis method. A randomized block experimental design with three replications was used to determine differences in carbon content (%). The results show that the highest average values of carbon in suspended sediment were recorded in native rangeland and under initial moisture conditions (3.79 %), whereas the best land cover conditions in the buffelgrass pastures and abandoned farmland plots (1.20 and 1.18 % respectively) had lower carbon losses than those that occurred in the native rangeland (3.11 %).

   Soil loss due to erosion by water is a problem that causes significant economic losses; for this reason, the aim of this study was to quantify soil loss in the Agustín Melgar watershed in Hydrologic Region number 36 by applying the Revised Universal Soil Loss Equation. A geographic information system was used to obtain distributed parameters of the studied equation. The results show that there are different soil loss levels in the watershed under study, ranging from “very low” (losses lower than 5 t·ha-1) to “extreme” (losses greater than 200 t·ha-1).

Irrigating crops with saline water induces adverse effects on productivity and causes deterioration of agricultural soils. NaCl is the most important toxic salt that induces ionic and osmotic stress in plants. Consequently, plants require a greater effort to absorb water, which affects their growth. A study was conducted in a greenhouse to determine the symbiotic effects of arbuscular mycorrhizal fungi (AMF) Burize ST® and Micorriza INIFAP® (Rhizophagus intraradices) on sorghum hybrids ‘Norteño’ and ‘Gstar 7609,’ subjected to irrigation with three levels of saline water (desalinated, medium and high, EC = 0.03, 2.30 and 4.54 dS·m-1, respectively). Variables measured were chlorophyll (SPAD), plant height, stem diameter, shoot and root biomass, and mycorrhizal colonization. Except for colonization, which was not influenced by the water’s salinity level, the values of the other variables decreased as the salt concentration in the water increased. The results indicated that, in general, higher growth and biomass yield were obtained in sorghum plants by the symbiotic association between the AMF Micorriza INIFAP and the sorghum ‘Norteño’ at the three salinity levels in the irrigation water.