The aim of this study was to determine the frequency and degree of infestation of varroatosis (Varroa destructor) and infection of nosemosis (Nosema spp.) in honeybee (Apis mellifera) colonies in the state of Zacatecas during the fall and spring. We inspected 299 commercial honeybee colonies located in 15 municipalities in the state of Zacatecas and in three different ecological zones: 1) temperate semi-dry, 2) semi-warm semi-dry, and 3) temperate sub-humid. Results showed a general prevalence of 2.3 % for nosemosis and 88 % for varroatosis. The varroa infestation level varied significantly (P = 0.05) between fall and spring, and among zones only during the spring (P < 0.001). Infestation levels of 5 % or higher were found in 44 % of the colonies during fall, while 28 % of them exceeded 5 % infestation levels in spring. Nosema spp. was only observed in 4.7 % of the sampled population in spring; most of the cases (86 %) were detected in the semi-warm semi-dry zone. The results of this study indicate that varroatosis is the most common parasitic disease of adult honeybees in the state of Zacatecas. Nosemois does not pose a serious problem for beekeeping in the state, due to its low frequency.

Pinus cembroides Zucc forests has usually been segregated from commercial logging given their woody disadvantages. However, this species plays an important role in the biodiversity of Mexico. The aim of the present study was to determine the concentration of carbon (C) in the main compartments of P. cembroides: root, bark, stem, branches, buds and leaves. The total C concentration expressed as percentage of biomass was determined with the Solids TOC Analyzer equipment. The results were analyzed in a completely randomized design and Tukey’s comparison of means. The analysis of variance evidenced that C concentration varied among components (P < 0.05); the bud had the highest value (57.1 %), while stem and branches recorded the lowest values (47.7 and 47.8 %, respectively). Our results contribute to improving C estimates for this species and provide important information to determine whether P. cembroides forests can be considered as a possible source with mitigation potential against climate change and thus use it in a C sequestration program.

Cedrela odorata L. is a species distinguished by the quality of its wood. Cedar established in the field must adapt to changes in resource availability; survival is greater when the root system is associated with microorganisms that improve nutrition and growth. The aim of this study was to evaluate the effect of Rhizophagus intraradices and Azospirillum brasilense on the growth of C. odorata and its nitrogen (N) and phosphorus (P) uptake capacity. Cedar seeds were sown in pots in accordance with the following treatments: control, 15N-15P-15K fertilization, R. intraradices, A. brasilense, R. intraradices + A. brasilense, and R. intraradices + A. brasilense + A. brasilense + 15N-15P-15K fertilization. Morphological and physiological yield variables and root colonization were recorded every 28 days, and N and P contents at the end of the experiment (140 days). In general, R. intraradices promoted greater plant growth (P ≤ 0.05) of morphological and physiological yield components. The maximum height (97 cm) was recorded in plants with R. intraradices + A. brasilense + 15N-15P-15K fertilization, representing 40 % more height than the control. N and P increased with the inoculation of the microorganisms alone and combined.

In 2013, in the east of Michoacán, die-back in commercial eucalyptus plantations appeared in trees with frost and drought damage. Neofusicoccum eucalyptorum was isolated on Eucalyptus nitens, and its teleomorph Botryosphaeria eucalyptorum was found on cankers; N. parvum isolated on E. nitens and E. globulus. Both species of Neofusicoccum were identified by morphology and were molecularly characterized by PCR-ITS. The sequences of N. eucalyptorum (access number: KC479184 and KC4799188) and N. parvum (KC479185, KC479186 and KC479187) were deposited in the Gene Bank of the NCBI. In the field, diseased eucalyptus showed die-back, fusiform cankers on stem, which induce bulges, resin flow and the appearance of epicormic shoots. The fungi inoculated in vitro in shoots of E. nitens and E. globulus provoked necrotic lesions and abundant immature pycnidia at 10 days after inoculation (dai). E. nitens trees of three years of age showed a fusiform canker with sunken appearance and dark brown coloration, measuring 13 to 21.9 cm at 48 dai. This study is the first report of N. eucalyptorum and N. parvum in Mexico causing disease in eucalyptus plantations.

The abundancia y riqueza de hongos micorrizógenos arbusculares (HMA), así como la micorriza arbuscular (MA) en las raíces de cuatro especies de helechos (Cheilanthes myriophylla, Ch. bonariensis, Blechnum appendiculatum y Adiantum capillus-veneris) se evaluaron en relación con la fertilidad del suelo durante febrero y diciembre. Los helechos se evaluaron en dos ecosistemas de Oaxaca, México: Ch. myriophylla y Ch. bonariensis en el matorral xerófilo semiárido, y B. appendiculatum y A. capillus-veneris en el bosque mesófilo de montaña. El suelo rizosférico de las cuatro especies tuvo mayor abundancia y riqueza de esporas de HMA que el suelo sin helechos. En total se registraron 13 géneros y 32 morfoespecies de HMA. Las morfoespecies de Glomus se detectaron en ambos ecosistemas, mientras que Racocetra, Scutellospora, Diversispora y Gigaspora fueron exclusivas del bosque mesófilo. La baja micorrización arbuscular se atribuyó a los altos niveles de materia orgánica, N total y P inorgánico; la MA fue más activa en Ch. bonariensis, especie del matorral xerófilo, lo cual sugiere que la MA es regulada por la disponibilidad de recursos y la identidad del helecho. Las cuatro especies forman reservorios de HMA, lo que indica que los helechos podrían generar inóculos nativos útiles para la restauración ambiental de sus ecosistemas.

Strains of Psathyrella spadicea, Floccularia aff. luteovirens, Clitocybe squamulosa, Flammulina mexicana and Lyophyllum aff. shimeji were obtained, their sporomes use to be collected and consumed by inhabitants of the Nevado de Toluca, Mexico. The strains were studied in vitro on six culture media (DFA: Dog food agar, MA: Maize agar, PDA-PL: potato dextrose-peptone and yeast agar, EMA-PL: malt extract agar peptone and yeast, PDA and EMA) at 18 °C and 25 °C. Species satisfactorily developed at 18 °C, F. mexicana and L. aff. shimeji had the highest growth rate and biomass production. Flammulina mexicana only developed at 18 °C showing higher growth and biomass production on DFA. The strain of L. aff. shimeji grew at 18 and 25 °C, the highest growth rate was recorded on PDA at 18 °C and highest biomass production on EMA-PL at 18 °C. Regarding the best conditions for the in vitro development of mycelium, primary spawn was obtained from F. mexicana and L. aff. shimeji in wheat and sorghum. The highest density and percentage of covered mycelium were obtained using wheat substrate.

The physico-mechanical properties of wood-plastic (WP) boards were evaluated and compared with those of conventional boards (sugarcane bagasse particleboard, plywood board and sugarcane bagasse fiberboard) more commonly used in Cuba. The WP board was made with waste from the forestry industry (sawdust), industrial waste (thermoplastics) and chemical additives in amounts of 50, 30 and 20%, respectively; the board was obtained by extrusion molding. Results were analyzed with the Kruskal-Wallis test and Fisher’s LSD post-hoc multiple comparisons analysis to determine differences relative to conventional boards. Results indicate that the physical properties of wood- plastic boards improved with increasing density. Water absorption and swelling were lower than in conventional boards, whereas the mechanical properties (bending, compression and tensile strength) were higher. Tensile strength, bending and compression in the wood-plastic boards were statistically similar (P> 0.05) in the plywood. Given their properties, it can be concluded that wood-plastic boards are able to replace both conventional and wood boards in outdoor conditions

Three irrigation periods (every 48, 96 and 192 hours) were evaluated with the purpose of improving the preconditioning Pinus engelmannii Carr. seedlings in nursery. Eight months old seedlings were evaluated for 40 days. The study was conducted under greenhouse conditions at the nursery of the Experimental Station Valle del Guadiana of INIFAP. The data were analyzed with a permutations test. The results show that irrigation every 48 h caused the best effects in height (7.70 cm), diameter (4.38 mm), total biomass (6.59 g) and Dickson’s quality index (0.55). In contrast, water stress caused by treatment with irrigation every 192 h (-1.22 MPa) limited the growth of seedlings; however, the lignification index (26.63) was significantly better (P = 0.0001) with this frequency of irrigation. Despite having significant differences (P = 0.0001) in the hydric potential and morphological variables, there was not sufficient evidence to define an absolutely superior treatment to improve the preconditioning of seedlings in the nursery. Therefore, it is advisable to evaluate these treatments for a longer time; moreover, it is suggested to evaluate the same treatments in the plantation field

The potential of the monarch butterfly (Danaus plexippus L.) as alternate host of natural enemies of pests was studied (from March 2012 to March 2013) at a plantation of Asclepias curassavica established at the Chapala Cienega, Villamar, Michoacán, Mexico. Therefore, Phytophagous eggs samples were collected and incubated in Petri dishes for the parasitism record. Results show that D. plexippus was present throughout the year in the study region, with the highest levels of oviposition during August-December. Trichogramma pretiosum Riley was the predominant parasitoid, with levels up to 100 % of parasitism; its major activity coincided with the highest levels of the phytophagous oviposition. Multiple emergences of parasitoids in each butterfly egg contribute to the increase of T. pretiosum populations in field. Therefore, based on this, D. plexippus can be considered an excellent alternate host of T. pretiosum, natural enemy of Lepidoptera pests. In addition, the proposed strategy seeks to contribute to the conservation and increase of monarch populations; both through the preservation of its host (A. curassavica), and by the eventual reduction in the use of insecticides to kill pests.

Caesalpinia gaumeri Greenm is an important timber species in the tropical deciduous forest in southeast Mexico. The trunks of this species are used as posts in rural construction. In this study we investigated which morphological and environmental factors influence annual diameter growth, in order to establish the best turnover period. Diameter growth in 32 trees located in four diameter categories were evaluated and classified according to quality and sunlight incidence on the crowns of the trees. The study lasted 22 months and the diameter at breast height was measured and recorded bi-monthly. The results indicate that Average Growth Rate (AGR) increased from the smallest to the largest diameter categories, from the damaged to the healthy crown qualities and from intermediate to total incidences of sunlight. Highest AGR was observed in diameter categories of 12.50 to 22.49 cm in trees with symmetrical crown quality and the crown under full sunlight. The cumulative AGR was highly significant (P < 0.001) and positively correlated (r = 0.94) with the precipitation. Good growth in diameter for C. gaumeri requires a combination of bigger stem diameter, healthy and symmetric crown, full incidence of sunlight on the crown and a rainy season.