The aboveground contributions of mangroves to global carbon sequestration reinforce the need to estimate biomass in these systems. The objective was to determine the aboveground biomass storage and quantify the carbon and CO₂e content in Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa present in southeastern Mexico. Based on the Forest Protocol for Mexico Version 2.0 methodology, published by Climate Action Reserve, 130 circular plots were randomly selected and established in an area of 930 ha of mangrove vegetation, and the aboveground biomass and stored carbon were determined. The mangrove had a density of 3515 ± 428.5 individuals per hectare. The aboveground biomass of the three species was 120.5 Mg ha⁻¹. The biomass of L. racemosa was 99.5 Mg ha⁻¹, which represents 82.6% of the total biomass. The biomass of R. mangle was 20.33 Mg ha⁻¹, and that of A. germinans was 0.32 Mg ha⁻¹. The total carbon retained in the trees was 60.25 Mg C ha⁻¹ and 221.1 Mg CO₂e ha⁻¹. Laguncularia racemosa generated the highest contributions of CO₂e. The area of mangroves accumulated 112,065 Mg of aboveground biomass. The carbon contained in this biomass corresponds to 205,623 Mg CO₂e. This mangrove contributes to mitigating the effects of climate change globally through the reduction in greenhouse gases.

Background: Capsicum spp. grow in environments with different incident radiation, that could modify the plant growth and the concentration of phytochemicals in fruits. Hypothesis: Shading positively affects phenology and fruit yield, decreases the total contents of phenols (TPC), flavonoids (FLV), proanthocyanidins (PAN) and carotenoids (CAT) in fruits of wild Capsicum species. Studied species: Capsicum annuum var. glabriusculum: amashito (AMA) and garbanzo (GAR), and C. frutescens (Pico Paloma, PIP) Study site and dates: Huimanguillo, Tabasco, Mexico; 2020 and 2021. Methods: Seeds were treated with gibberellic acid (GA3) (500 mg L-1) for 24 h prior to seeding. The seedlings were transplanted in an open field and under two levels of shade (35 and 70 %) under a subsplit plot design with four replicates. TPC, FLV, PAN and CAT were determinate in immature and ripe fruits by UV-vis spectrophotometry. Results: Shade accelerated the phenological processes from the first bifurcation of the stem, and decreased the fruits ripening time from anthesis of the genotypes studied. Shade only increased the yield of the AMA genotype and reduced the contents of TPC, FLV, and CAT; however, these metabolites increased under open field conditions. Conclusions: The shade reduced the duration of phenological stages including the ripening period of fruits, and increased the plant height of the Capsicum spp. The increase in yield by shading effect only was observed in AMA genotype. The content of phytochemicals in Capsicum fruits is reduced by shading levels.

The standardized methods used in carbon markets require measurement of the biomass and carbon stored in trees, which can be quantified through allometric equations. The objective of this study was to analyze aboveground biomass estimates with allometric models in three mangrove species and compare them with those used by the Climate Action Reserve (CAR) standard. The mangrove forest in Tabasco, Mexico, was certified with the Forest Protocol for Mexico Version 2.0 (FPM) of the CAR standard. Allometric equations for mangrove species were reviewed to determine the most suitable equation for the calculation of biomass. The predictions of the allometric equations of the FPM were analyzed with data from Tabasco from the National Forest and Soil Inventory 2015–2020, and the percentages of trees within the ranges of diameters of the FPM equations were determined. The FPM equations generated higher biomass values for Rhizophora mangle and lower values for Avicennia germinans than the seven equations with which they were compared. In the mangrove swamp of Ejido Úrsulo Galván, Tabasco, 81.8% of the biomass of A. germinans, 34.4% of Laguncularia racemosa and 24.0% of R. mangle were within the diameter range of the FPM equations, and in Tabasco, 28.5% of A. germinans, 16.7% of L. racemosa and 5.7% of R. mangle were within the diameter range. For A. germinans and R. mangle, we recommend using the equation that considers greater maximum diameters. The allometric equations of the FPM do not adequately predict a large percentage of the biomass.

This study was carried out to evaluate the yield and quality of pineapple fruits of the cultivars MD2, Smooth Cayenne, and Cabezona from plants treated with 2‐(3‐chlorophenoxy) propionic acid (CPA) in the humid tropics of Mexico with respect to three planting dates and two planting densities. The experimental design used was a scheme in sub‐subdivided plots with four replications. The pineapple cultivars were established on three planting dates (February 28, April 28, and June 28, 2022) at two planting densities, that is, those typically used at the regional level (Density 1: MD2 and Smooth Cayenne, 36,000 plants ha ⁻¹ ; Cabezona, 26,500 plants ha ⁻¹ ), and an increase of 28% in the number of plants planted in Density 1 for each cultivar (Density 2). For floral inhibition, 120 g CPA ha ⁻¹ was applied at each density and divided into three applications every 10 days beginning on October 20, 2022. The results revealed that the fruit yield and concentration of total flavonoids were not affected by the planting date, but the fruit/crown ratio, pH, °Brix, percentage of citric acid, maturity index, and total polyphenol concentration (TPC) were. The planting density significantly affected the yield, pH, and maturity index. The yield of the cultivars in Density 2 was 33% higher than that in Density 1, even though the fruits weighed 3.5% less and exhibited decreased °Brix and maturity index values. The fruits harvested from October to November (planting date June 28) presented the highest TPC (89.76 mg 100 g FF ⁻¹ ). Among the cultivars, MD2 and Cabezona presented the highest TPC. It is concluded that it is possible to produce pineapples in seasons of product shortage by modifying the dates and planting density without affecting the quality of the product.

It has been shown that environmental factors such as light quality and intensity, as well as the lighting regime (photoperiod or continuous light) affect the development of explants in micropropagation systems, due to the induction of physiological responses of different nature. The objective of this research was to evaluate the effect of LED light sources of different spectral composition and growth regulators 6-BAP and 2,4-D at different concentrations on the in vitro development of Laelia anceps Lindl. seedlings. In addition, seedlings obtained in vitro were evaluated in two culture media (semisolid and liquid). The variables evaluated were number of shoots, number of roots, number of leaves, dry matter, chlorophyll a, b, total and carotenoid content. Analyses of variance (ANOVA) were performed with the data and means were compared with the LSD test (p ≤ 0.05). The highest mean number of shoots (4.44 ± 0.44) and number of roots (3.11 ± 1.54) were obtained in the treatment containing 10 mg L-1 of 6-BAP and exposed to red + blue LED light, while the concentration of photosynthetic pigments was higher in the treatment with white and red light. The use of liquid culture medium (temporary immersion systems) showed no significant differences between the tested treatments when compared to the semisolid culture medium.

Microbial toxicity tests in the rhizosphere play an important role in the risk assessment and phytoremediation of chemical compounds in the environment. Tests for the inhibition of nodule number (NN), Rhizobia in the rhizosphere (RhR), Rhizobium in nodules (RhN) and arbuscular mycorrhizal fungi (AMFs) are important to evaluate the toxicity as well as the removal of total petroleum hydrocarbons (TPHs), 15 linear alkanes (LAs), and total linear alkanes (TLAs). The inhibition and removal was evaluated at 60 (vegetative stage, VS) and 154 days (reproductive stage, RS) of the life cycle of Crotalaria incana and Crotalaria pallida in soil with four doses of CRO (3, 15, 30, and 45 g/kg) plus a control (16 treatments). Results indicated that RhN and five structures of the AMFs present an index of toxicity (IT < 1), and the microbiological variable is inhibited by the CRO. RhR exhibits a hormesis index (IT > 1) that is stimulated by the CRO in the VS and RS for C. incana and C. pallida. The highest removal of TPHs (77%) was in the rhizosphere of C. incana in the RS with 45 g/kg of CRO. C. pallida removed the greatest amount of TLA (91%). There was a positive correlation between the RhR and the removal of TPHs, TLA, and LAs (higher molecular weight). It could be argued that symbiotic microorganisms are significant for use in toxicity testing, and the rhizosphere of C. incana and C. pallida can be used for the phytoremediation of HTPs and ALs in loamy-clay soil contaminated with CRO.