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Los sistemas agroforestales combinan árboles frutales con cultivos agrícolas, brindando beneficios ambientales y productivos. Este estudio determinó el efecto de la aplicación combinada de hongos micorrícicos arbusculares (HMA), Rhizobium y niveles de fertilización mineral sobre las características agronómicas y fisiológicas del maíz (Zea mays L.) y frijol (Phaseolus vulgaris L.) intercalados con durazno (Prunus persica), limón persa (Citrus latifolia Tan.) y lichi (Litchi chinensis), así como algunos cambios en las propiedades físicas, químicas y microbiológicas del suelo. Se estableció un sistema agroforestal durante el ciclo agrícola otoño-invierno de 2020 en la comunidad de Campo Grande, municipio de Ixtaczoquitlán, Veracruz, México. El tratamiento con Rhizophagus irregularis+Rhizobium etli (2)+50% de fertilización mineral produjo los mayores aumentos en la altura de las plantas: 68.5±8.6 cm (limón persa), 105.3±11.0 cm (durazno) y 6.8±4.5 cm (lichi). Además, produjo el mayor rendimiento de grano en maíz (5 653.7 kg ha-1) intercalado con frijol (995.1 kg ha-1). Al final del primer ciclo productivo, el pH del suelo disminuyó de moderadamente ácido (5.7) a ácido (4.9). Por el contrario, la materia orgánica aumentó de 1.71 a 2.76%. Hubo un aumento en la cantidad de bacterias (55.0 x 106 a 68.0 x 106 UFC g-1 de suelo), hongos (73.55 x 102 a 511.7 x 102 UFC g-1de suelo) y actinomicetos (48.61 x 105 a 53.19 x 105 UFC g-1 de suelo). El establecimiento de sistemas agrícolas diversificados en combinación con consorcios microbianos promueve la productividad de los cultivos y mejora las propiedades físicas, químicas y microbiológicas del suelo.

Corn germplasm with different mesocotyl elongation was characterized for High Valleys in Mexico by estimating the general combinatory aptitude (GCA), specific combinatory aptitude (SCA), heterosis (H), inbreeding depression (ID) and principal component aptitude (PCA), with the purpose of directing the improvement for deep sowing. The hypothesis was that the parents and crosses of mesocotyl present variability in seedling and adult plant traits based on deep sowing. The 36 F1 and F2 crosses—derived from nine parents, three with short mesocotyl (S), three medium (M) and three long (L), obtained through Griffing diallel II—plus the parents were planted in sand beds and polyethylene bags in a greenhouse during the spring–summer cycles of 2021 and 2022. The following traits were measured: length of mesocotyl (LM), length of coleoptile, total seedling dry matter and 10 cob traits in addition to total dry matter. In 11 of the 14 traits, there was a positive and significant correlation (p ≤ 0.05) between the GCA of the parents and their LM. The highest SCA, H and ID (p ≤ 0.05) were for crosses L × L for all the traits measured. When comparing the GCA/SCA proportions, this relation varied from 0.76 to 0.97, which points to practically equal additive effects with those of dominance; however, in parents and L × L crosses, this relation was on average 0.94, 1.07 in M × M, 0.22 in S × S and 0.36 in L × S. In both F1 and F2, the variation was explained by two principal components: 89.5% for GCA and 73.4% for SCA. In both generations, the parents with higher GCA were H-48, HS-2 and Promesa, the three with long mesocotyl, while those with the highest GCA were crosses between these three hybrids.

Objetivo. Se evaluó el potencial alimenticio de híbridos de maíz Puma como forraje ensilado en un 50% de la dieta de ovejas gestantes. Materiales y métodos. 61 ovejas gestantes fueron, asignadas a los grupos: Centli Puma (N = 21), Tsiri Puma (N = 20) y Tlaoli Puma (N = 20), y se les midió el peso, la condición corporal (CC), FAMACHA y perfil metabólico en la gestación, así como la producción y calidad de leche a los 15 y 30 días de lactancia. En los corderos se midió la temperatura al nacimiento y el peso. Resultados. El peso y CC de las ovejas durante la gestación y en la lactancia no fueron afectados por el grupo (p>0.05). Por su parte el consumo estimado de alimento fue mayor en las ovejas del grupo Centli (p0.05). El peso de los corderos y su temperatura no varió entre los tres grupos (p>0.05). Conclusiones. El uso de ensilados de híbridos de maíz Puma desarrollados para producción de grano, tiene buenas y similares respuestas en los parámetros productivos y metabólicos de ovejas, así como en los corderos.

Photosynthesis is one of the essential processes for life on the planet. Photosynthesis cannot be measured directly because this complex process involves different variables; therefore, if some variables of interest are integrated and measured, photosynthesis can be inferred through a mathematical model. This article presents a fuzzy mathematical model to estimate photosynthesis. This approach uses as input variables: Soil moisture, ambient temperature, incident radiation, relative humidity, and leaf temperature. The fuzzy system was trained through data obtained from experiments with jalapeño pepper plants and then validated against the LI-COR Li-6800 equipment. The correlation coefficient (R2) obtained was 0.95, which is a higher value than some published in the literature. Based on the Takagi-Sugeno method, the proposed model was designed and implemented on the MATLAB platform using ANFIS (adaptive neuro-fuzzy inference system) to determine the parameters, thus achieving a high-precision model. In addition, the fuzzy model can predict photosynthesis at different temperature changes, soil moisture levels, and light levels. The results of this study indicate the possibility of modeling photosynthesis using the fuzzy logic technique, whose performance is much higher than other methods published in recent articles.

Background. The use of improved seeds in Mexico is limited. To increase its use and improve its supply, it is necessary to promote the generation of micro-enterprises; for this, the Universidad Nacional Autónoma de México (UNAM) and Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) work in a coordinated manner on the development of new varieties. Objective. To determine the seed productivity by effect of the population density of the trilinear hybrid of H-53 AE maize and its simple progenitor crosses in two environments of Valles Altos. Methodology. In the spring-summer cycle of 2014, in Cuautitlán Izcalli and Texcoco, State of Mexico, three genotypes were evaluated: the simple female cross androsterile (M53AE x M59) and fertile version (M53F x M59), as well as the trilineal hybrid H-53 AE. Population densities were 55,000, 70,000, and 85,000 ha-1 plants, respectively. The variables evaluated were male and female flowering, plant and ear height, volumetric weight, weight of 200 grains, ear length, grains per row, dry matter percentage, and grain percentage. The experimental design employed a factorial design with random complete blocks, and the Tukey method was used for mean comparison. Results. The simple crosses, androsterile and fertile, exceeded the performance of the hybrid trilineal H-53 AE (7280 Kg ha-1). The population density where genotypes expressed a higher yield was 70, 000 ha-1 plants, with 8602 Kg ha-1, significantly different to 7813 Kg ha-1, and 7748 Kg ha-1 for 85,000 and 55, 000 ha-1 plants, respectively. Implications. Further analysis of other environmental factors should be carried out to strengthen the recommendation of the evaluated trilinear hybrid. Conclusion. The best responses were presented in the population density of 70,000 plants ha-1, and the highest average yield of three genotypes and three population densities with 8768 Kg ha-1 was in the FESC environment (Cuautitlán Izcalli).