Efecto del uso de suelo en las hormigas (Formicidae: Hymenoptera) de Tikinmul, Campeche, México

The effect of land use on ants was compared in Tikinmul, Campeche, Mexico. The research was carried out in cedar monocultures and home gardens, during dry and wet seasons. TSBFmethod modified to agroforestry systems was used to collect ants. 37 species were collected, nine of which were exclusive to both systems, while 19 were present in both systems. A similarity (Sörensen index) of 60.4% between systems and 68% between seasons was observed. The Myrmecinae Subfamily with eight genera and 17 species was the most represented. Solenopsis geminata and Dorymyrmex sp. were dominant and indicator species of monoculture system. Ant density was higher in monocultures. A direct relationship between management intensity and species richness was not found. Litter amount appear to be the determinant factor to define ants abundance. Ants populations were affected indirectly by agrochemicals. Se comparó el efecto del uso de suelo sobre la mirmecofauna del ejido de Tikinmul, Campeche, México. El estudio se llevó a cabo en monocultivos de cedro y huertos caseros, durante la época seca y lluviosa. Para la colecta de especies se utilizó el método Tropical Soil Biology and Fertility (TSBF) modificado para sistemas agroforestales. Se encontraron un total de 37 morfoespecies, de las cuales nueve son exclusivas de cada uno de los dos sistemas, mientras 19 están presentes en ambos. Se observa una similitud (Sörensen) de 60.4% entre sistemas y 68% entre épocas. La subfamilia Myrmicinae con 8 géneros y 17 especies fue la mejor representada en el estudio. Solenopsis geminata y Dorymyrmex sp.fueron especies dominantes e indicadoras del monocultivo. La densidad de hormigas fue más alta en los monocultivos. No se encontró relación directa de la intensidad de manejo con la riqueza de especies. La cantidad de hojarasca se muestra como el factor determinante de abundancia de las hormigas. Los agroquímicos afectan de manera indirecta a sus poblaciones.

Seed germination of four amaranth species (Amaranthus spp.)

Amaranth (Amarantus spp.) is an important species for its benefits in human and animal nutrition, therefore, the reproduction of these species is important, supported by rigorous experiments that generate quality information. Consequently, the present work aimed to determine the germination of 20 accessions of four species of Amaranthus spp. This was carried out at the Technological Institute of Chiná, Campeche, Mexico, with seeds donated by The North Central Regional Plant Introduction Station (NCRPIS), Iowa State University, from Africa, Asia, Greece, South America, USA, and Mexico. The seeds were weighed and measured, then they were sown in Petri dishes and kept in a germination chamber at 27 ºC and a relative humidity of 54 % in the dark, every 24 hours the germinated seeds were counted and removed. The analyzes were performed using the ANOVA test to identify differences in weight, length and germination between accessions. The results did not show statistical differences in seed length, between species or between accessions, with respect to weight if there were statistical differences both between species and between accessions. The results showed that A. hypochondriacus from India had the highest weight (0.00093 ± 0.000075 g). Germination did obtain statistical differences in the different evaluation times, at 24 and 48 hours, where the highest germination was in the species A. hypochondriacus and A cruentus. Therefore, it is concluded that seed germination is different in each species and accession.Amaranthus (Amaranthus spp.) is a species of great importance that benefits human and animal nutrition; therefore, its reproduction must be based on useful information obtained from rigorous experiments. Consequently, the aim of this work was to determine the germination of 20 accessions from four Amaranthus spp. The work was carried out at the Instituto Tecnológico de Chiná, Campeche, Mexico, using seeds from Africa, Asia, Greece, South America, the US, and Mexico, donated by The North Central Regional Plant Introduction Station (NCRPIS), Iowa State University. After they were weighed and measured, the seeds were placed in Petri dishes and kept in the dark inside a germination chamber, at 27 ºC and with a 54% relative humidity. Germinated seeds were counted and removed every 24 hours. The analyses were carried out using the ANOVA test in order to identify weight, length, and germination differences between accessions. The results showed no statistical differences in seed length, neither between species nor accessions; however, there were statistical differences in the weight, both between species and between accessions. A. hypochondriacus from India recorded the highest weight (0.00093 ± 0.000075 g). Regarding germination, there were statistical differences between the various evaluation periods (24 and 48 hours): the highest germination was recorded by A. hypochondriacus and A cruentus. Therefore, the following conclusion was reached: seed germination is different between species and accessions

Vermicompost and Mycorrhizae Use on Cedrela odorata L. Growth in Nursery Conditions

Objective: to evaluate the effect of mycorrhizal inoculation and the use of vermicompost on the growth of red cedar (Cedrela odorata L.) seedlings under nursery conditions. Materials and methods: the treatments were no inoculation and inoculation with Glomus intraradices, combined with different amounts of vermicompost in the growth substrate (0, 10, 20 and 30%), in a randomized complete block design. The variables evaluated plant height (AP), stem diameter (DT), number of leaves (NH), dry weight (PS), mycorrhizal colonization (CM) and number of spores (NE). Results and discussion: The use of vermicompost in the growth substrate of the plants favored the growth of C. odorata seedlings, being the best treatment 30% of vermicompost without mycorrhiza. The percentage of mycorrhizal colonization and number of spores per 100g of soil decreased with increasing the amount of vermicompost in the substrate. Conclusions: vermicompost was the main growth promoter of C. odorata plants under nursery conditions.Objective: To evaluate the effect of mycorrhizal inoculation and the use ofvermicompost on the growth of red cedar (Cedrela odorata L.) seedlings under nurseryconditions.Materials and Methods: The treatments were with and without a Glomus intraradicesinoculum, combined with different amounts of vermicompost in the growth substrate (0,10, 20 and 30 %), in a completely randomized block design. The variables evaluatedwere plant height (PH), stem diameter (SD), number of leaves (NL), dry weight (DW),mycorrhizal colonization (MC) and number of spores (NS).Results: The addition of vermicompost to the growth substrate improved the growth ofC. odorata seedlings, the best treatment being 30% of vermicompost withoutmycorrhizae. The percentage of mycorrhizal colonization and number of spores per 100g of soil decreased when increasing the amount of vermicompost in the substrate.Study Limitations/Implications: None. Findings/Conclusions: Vermicompost was the leading promoter of C. odorata plantgrowth under nursery conditions

Experiencias de agroforestería en México

Cuadernillo especializado en actividades de agroforestería y ciencias ligadas a la naturaleza,El presente trabajo es una colección de los Cuadernos de Divulgación Ambiental, que constituyen un acercamiento inicial a tópicos ambientales de nuestro tiempo, abordados con una visión amplia y considerando diferentes ópticas. Con rigor académico, pretenden contribuir al conocimiento y la difusión de situaciones y problemáticas socio-ambientales, así como al entendimiento de sus dilemas, retos y oportunidades.Secretaría de Medio Ambiente y Recursos Naturales (Semarnat