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The most widely produced grain legume for human consumption in the world is the common bean (Phaseolus vulgaris L.). This plant is native to the Americas, where it plays an important role in the daily diet. The environment where beans are grown is varied, from tropical zones to high mountains, with different growth habits and production systems, from highly technical to traditional. Therefore, efforts in bean crop modeling should start from identifying the type of bean and the target system. Beans are very sensitive to abiotic stress, a fact that has encouraged the modeling of their possible response under climate change scenarios. For this, a literature review was carried out to identify modeling exercises carried out in Latin America, which include growth studies (node production rates and leaf area), phenology and yield. The models used in these studies include EcoCrop, CROPGRO-DRYBEAN (implemented on the DSSAT platform), and in one case of each, Maxent and CLIMEX. Four studies are described in detail: in the two countries with the highest production in the world (Brazil and Mexico), and in Central America as a region highly vulnerable to climate change. Studies agree that bean productivity could suffer serious negative effects in the course of the 21st century because of climate change. Finally, a recent exercise to collect historical data from bean trials in Latin America is reported to feed future modeling efforts. [ABSTRACT FROM AUTHOR]

Experimental observations of growth and development variables of a crop constitute the basic information for the calibration of crop models. Considering the above, this work was developed at the National Institute of Agricultural Sciences during the dry season 2016-2017, with the objective of determining the physiological and agronomic variables of a maize cultivar. A planting density of 47,619 plants ha-1 was used with a quasi-experimental design on a Leached Red Ferralitic Soil. From 15 days after emergence (DDE), destructive sampling was carried out. The Leaf Area Index (LAI), the total dry mass of the aerial part and the grain growth were determined. Phenological observations were made during the crop cycle. The data was adjusted to different mathematical functions with the statistical program Statgraphics Plus 5.0. Next, the Absolute Growth Rate (AGR) of the dry matter and the Grain Filling Rate (TLlG) were calculated. Agricultural yield in dry grain and its components as well as the Harvest Index (CI) were evaluated. In conclusion, the primary data of 16 variables were obtained for the calibration of the Decision Support System for Agrotechnology Transfer (DSSAT) model.. [ABSTRACT FROM AUTHOR]

Bats are among the most valuable pollinators of economically important crops in Mexico including agaves and columnar cacti. High demand for the agricultural products of these crops has resulted in increasing use of agrochemicals, including pesticides and fertilizers, to increase yield and decrease pest damage. However, these compounds can negatively affect crop mutualists such as pollinating bats. In this study, we investigated: (i) how the application of the broad-spectrum pesticide carbamate and/or synthetic fertilizers affect crop yield of the pitaya cacti (Stenocereus queretaroensis); (ii) whether carbamate bioaccumulates in pitaya nectar and fruits; and (iii) whether the application of these agrochemicals affects visitation rates of the pitaya’s most efficient pollinators, nectarivorous bats of the genus Leptonycteris. We designed an experiment consisting of four treatments (pesticide, nutrients, both, or neither) applied to pitaya plants. We estimated the effect of each treatment by quantifying pitaya reproductive structures (flower buds and flowers) and fruit yield and quality, performed trace analysis to detect the pesticide in the nectar and fruits, and estimated bat flower visitation rates using camera traps to determine whether the addition of agrochemicals influenced pitaya–bat interactions. We found that none of the treatments increased yield or fruit sweetness, and they did not affect bat visitation rates. Fruit pulp and floral nectar contained pesticide concentrations above those permitted by international environmental agencies. Thus, our results show that adding these agrochemicals to pitaya crops does not improve yield but could negatively affect their crop pollinators, especially since bats apparently do not avoid visiting flowers containing pesticide residues. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) is considered a staple in the diet of hundreds of people. In Colombia, during 2017, a production of 2.8 million tons was registered, being the variety Diacol Capiro most planted for industrial processing in the departments of Cundinamarca, Boyacá and Nariño. The crop is sensitive to water deficit and it is the most limiting factor in production, therefore, irrigation is an essential practice which is being done by spraying with low efficiency, while drip irrigation can achieve efficiencies close to 90 %. An experiment was carried out under field conditions aiming to evaluate the effect of two irrigation systems (drip vs spray) on the production, quality, and efficient use of water in the Diacol Capiro variety potato crop in the municipality of Toca, Boyacá. A completely randomized experimental design was used with 2 treatments corresponding to each irrigation system and 3 repetitions. At 28 days after sowing (das) sprouting percentage, yield and quality of tubers were measured and harvest and efficient water use was calculated for fresh tubers. Statistical differences were observed for the evaluated treatments (p <0.05) in germination and efficient use of water; other variables did not show statistical differences. With two treatments the productive potential of the variety was reached but the drip irrigation presented the best results, producing an additional 3.49 kg of fresh tubers per m3 of water used. [ABSTRACT FROM AUTHOR]

Biochar is recognized as a sustainable alternative for the management of agro-industrial waste and has been extensively shown to be a beneficial organic amendment that improves soil quality and provides essential nutrients for plant growth. In this study, the effects of different treatments and doses of biocarbon, produced from the pyrolysis of agro-industrial wastes from palm rachis and coffee pulp, were assessed in terms of their impact on the physicochemical properties of soil and several plant growth variables for bell pepper and bean plants. Six qualities of biocarbon (three from coffee pulp and three from palm rachis) were produced by varying the pyrolysis temperatures at 250, 300, and 350 °C. Each was then applied to soil samples containing bell pepper and bean seeds at doses of 10, 20, and 30%. Treatments using palm rachis biocarbon were observed to result in the greatest increases in pH, electrical conductivity (EC), and cation exchange capacity (CEC), thereby enhancing the availability of essential nutrients such as phosphorus (P), magnesium (Mg), and potassium (K). However, it is inferred that high concentrations of these nutrients might unbalance the soil and negatively affect plant growth. Regarding plant development, coffee pulp biocarbons demonstrated a positive effect on the number of leaves, height, and both above-ground and below-ground dry mass compared to the palm rachis treatments. These findings suggest that biocarbon derived from coffee pulp could be particularly useful for enhancing both soil characteristics and crop yield. [ABSTRACT FROM AUTHOR]

In Mexico, in the last five years, there was a 189.50 to 13 219.84 hectares increase in sunflower crop surface under rainfed conditions. Particularly, in 2016, in the state of Guanajuato, approximately 450 hectares were planted. Cultivation under rainfed conditions requires planning including bioclimatic variables to reach the optimal crop yield and development. This work aims to identify bioclimatic potential areas for sunflower cultivation under rainfed conditions in Guanajuato. In autumn-winter 2016, 45 sunflower fields (distributed in eleven towns) were monitored and stratified. Crop yield associated to maximum and minimum temperature, relative humidity, solar radiation, precipitation and evapotranspiration were recorded. The data from fields with higher yield than 1.89 t/ha were used to generate polygons with a saturation of 56 abundance points, to calculate the potential distribution using the Maxent software, with 23 bioclimatic variables as predictors. The variables with the highest contribution percentage to the potential distribution were: average temperature of the driest quarter, altitude, moisture regime, and edaphic profile. The potential areas for sunflower cultivation had a surface of 317 028 hectares where the predominant climate is sub-humid warm, the annual mean temperature is 20 °C, the annual mean rainfall is 600 to 800 mm, and the altitude ranges from 500 to 1500 masl. [ABSTRACT FROM AUTHOR]

The productivity of pastures and forage is increasingly limited due to climate variability and prolonged drought periods. For that reason, it is necessary to cultivate plants that are tolerant and productive under conditionsof seasonal drought. The objective of this work was to characterize the agronomic and productive performance of new drought tolerant Cenchrus purpureus cultivars. Three cultivars (CT-601, CT-603, and CT-605) were used at different regrowth ages (60, 80, 100, and 120 days) in two climatic periods: rainfall and low rainfall from 2013 to 2014 in a representative ecosystem of Cauto Valley, Cuba. The cultivars were grown on Vertisol and were fertilized with organic fertilizer at a rate of 25 t/ha. Some agronomic variables and dry matter (DM) yield (t/ha) were evaluated under rainfed conditions. A randomized block design with factorial arrangement and its interaction (3x4x2) was used. DM yield was affected by the the second order interaction, during the period of rainfall, CT-605 at the age of 120 days reached the best average (p≤0.001) and during the period of low rainfall, CT-603 and CT-605 were highlighted (p≤0.001) . Weatherseason interaction on cultivars had a significantly positive impact (p≤0.001) on the length of leaves of CT-601 in the period of rainfall. CT-605 increased (p≤0.001) the percentage of leaves and green stems in the period of rainfall, superscripts were equalized in the dry season. Cultivars showed an acceptable DM yield during the low rainfall period, morphological changes neather affected the development nor the productivity. [ABSTRACT FROM AUTHOR]

The stomatal characteristics and chlorophyll concentration are some of the main parameters, to determine plant productivity. The objective of the present study was to characterize the stomatal density and distribution to estimate the chlorophyll concentration and evaluate their effect on the biomass production of sideoats grama [Bouteloua curtipendula (Michx.) Torr.] genotypes. The experiment was performed from May to July 2015 under greenhouse conditions, at- the School of Animal Sciences and Ecology of the Autonomous University of Chihuahua, Mexico. Three commercial varieties were studied: El Reno, Niner, Vaughn and two native genotypes: E-689 and E-592 of sideoats grama. The variables evaluated were chlorophyll concentration index (CCI), stomatal density (SD), trichome density (TD), stomatal index (SI), and stomatal area (SA). These variables were related to biomass production (BP) applying regression analysis. SD and SI showed a negative effect on BP, while SA and CCI showed a positive effect. The genotype E-689 showed the lowest (p<0.05) SD and SI, with values from 152.7 to 275 stomatal/μm2 and from 13.41 to 16.03%, respectively. In addition, it also presented the highest (p<0.05) SA and BP, with values from 186.7 to 361.7 μm2 and 13.5 to 30.3 g, respectively. In conclusion, genotypes of sideoats grama with lower stomataldensity and stomatal index and higher stomatal area and chlorophyll concentration index, could produce higher amounts of biomass. [ABSTRACT FROM AUTHOR]

El artículo analiza la dinámica de maíz y producción de frijol en México, el precio de mercado del maíz y frijol y las políticas agrícolas en México.

The work was developed in the farm "Las Papas", belonging to the National Institute of Agricultural Sciences (INCA); located at the 23° 00' north latitude and 82° 12' west longitude, to a height of 138 m above sea level in San José de las Lajas, Mayabeque. With the objective of evaluating the responses elicited in performance, product variations of temperatures during the crop cycle, the Roman variety plantations were made during the years 2014 and 2015, respectively. The behavior of the minimum temperatures, average and maximum and the amplitude of these was assessed. The total and commercial yield in t ha-1 and the composition of the tuber size was estimated. Statistical processing was performed with the use of Statgraphycs v5.1 program and graphics were performed using the Sigma Plot v3.1 program. [ABSTRACT FROM AUTHOR]

In agricultural activities developed in the department of Nariño are produced organic wastes. This wastes aren't disposed properly and could generate environmental pollution problems. These residues can be transformed and one of the most used alternatives is the technique of composting. In this study, a completely randomized experimental design with triplicate tests was developed, with three treatments of organic fertilizer production, obtained from marketplace waste, pea crop residues, and the source of dung used was varied. Treatments were inoculated with a solution of effective microorganisms. The response variables were the yield of composting process, organic fertilizer stabilization time and effectiveness in pea crop (number of pots per plant, number of grains per pot and yield per plot) and yellow potato crop (thick potato percentage and yield per plot). In the composting process the best treatment was the organic fertilizer produced with bovine and guinea pig dung, because it had a yield of 41.23% and a stabilization period of 50 days. In the field test, significant differences was presented with the analysis of number of pods per plant and yield per plots in pea crop, and yield per plots in yellow potato crop. Treatments with organic fertilizer application (5 tons/hectare) had best results than control treatment with chemical fertilizer application, but without differences among them. [ABSTRACT FROM AUTHOR]

This work was carried out in the areas from Los Palacios Rice Research Station of INCA, Pinar del Río, using INCA LP-5 and Reforma as short-cycle varieties, besides INCA LP-2 and J-104 as mid-cycle ones, during the dry season of January 2004 and February 2005, on an Ironstone Nodular Gley Hydromorphic soil, with the objective of evaluating the behavior of rice varietal growth and productivity. A direct seeding technology was employed with a pattern of 120 kg.ha-1. Agrotechnical activities followed rice crop technical instructions. A randomized block design with four replications and 25-m² experimental plots was used. Dry matter of the aerial part of plants (g.m-2) was determined in a 25-m² frame and samplings were fortnightly performed 25 days after germination until harvest. The absolute growth rate and leaf area index were calculated, besides determining agricultural yields and its main components; all data were processed by means of a single Anova through Duncan's multiple range test (p<0.05). Considering the results, it should be highlighted that agricultural yield was higher in short-cycle varieties than in the mid-cycle ones, with higher leaf area index values in those varieties. Radiation availability during the reproductive phase at the sowing date of February 2005 was a limiting factor for the varieties to reach top dry matter production and so to achieve higher yields. The best results of INCA LP-5 and Reforma could be related to varietal genetic characteristics, which are recommended for the breeding programs to search for new more productive cultivars. [ABSTRACT FROM AUTHOR]

This work was carried out at Los Palacios Rice Research Station, Pinar del Río, using INCA LP-5 and Reforma varieties, within the dry season of 2004, on a Ferruginous Nodular Gley Hydromorphic soil, with the objective of determining growth dynamics, yield and its main components. The direct seeding technology was applied with a norm of 20 kg.ha-1. Cropping activities followed rice technical instructions. A randomized block design with four replications was used and experimental plots had a 25 m2 area. Dry matter from the aerial part of plants (g.m2) was calculated in a 25-m2 frame and samplings started 25 days after germination, at variable intervals, up to grain maturity. Absolute growth rate (AGR) of the aerial part, agricultural yield and its main components were also calculated, whereas means were compared through T Student test (p<0.05). Results proved that INCA LP-5 kept a quicker growth rate and biomass accumulation than Reforma variety during the whole cycle, besides surpassing the latter one regarding agricultural yield, showing highly significant differences. [ABSTRACT FROM AUTHOR]

This study was conducted at "Los Palacios" Rice Research Station areas of Pinar del Río, where the shortterm rice variety INCA LP-5 was planted in May, 2003, on a Ferruginous Nodular Gley Hidromorphic soil, with the aim of evaluating the effect of a new production form (SICA) over some growth variables and yield, compared to the direct seeding system pattern of 120 kg.ha-1 seeds. A randomized block design with two treatments and four replicates was used, besides determining the aerial part dry weight (g) and leaf area (m²) within a 0.50-m²-frame in each treatment at the phenological phases of maximum tillering, flowering and maturation; also yield and its components were calculated at harvesting time. Data were processed through a Student T (p<0.05). Those plants growing under SICA conditions showed better growth variables, the highest differences being recorded on the leaf area index (IAF) at flowering phase, but they tended to decrease at maturity stage. A similar situation was observed with yield and its components. Studies on this subject are recommended to be followed with other varieties, besides deepening on the grain-filling process under this plantation system. [ABSTRACT FROM AUTHOR]