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Background: mango is cultivated in most tropical and subtropical regions of the world, it is estimated that there are more than a thousand cultivars, so its regional characterization represents a priority in countries such as Mexico, which holds the first place for export. Objective: the objective of the present study was to identify biochemical characteristics (photosynthetic pigments, type and proportion of carbohydrates) of eight recently introduced cultivars and two new selections in Mexico. Methodology: by spectrophotometric analysis, the concentrations of total sugars, reducing sugars and starches were evaluated, as well as the content of chlorophylls a, b and carotenoids of the cultivars 'Nam Doc Mai', 'Rosygold', 'Mallika', 'Ivory', 'Alphonse', 'Neelum', 'Fairchild', 'Kesar', 'Ataúlfo Diamante' and 'Ataúlfo Zafiro'. Results: in the case of total and reducing sugars, the cultivars ‘Kesar’, ‘Nam Doc Mai’, ‘Ivory’, ‘Mallika’ and ‘A. Zafiro' (0.42, 0.34, 0.34, 0.33, and 0.32 mg*g-1 pf-1) presented the highest values (respectively), the starch content was very heterogeneous and 'Rosygold' (0.36 mg*g-1 pf-1) was identified as cultivar with higher levels. The results showed ‘Ivory’ (0.64, 0.59, 0.27 mg*g-1 pf-1) as the cultivar with the highest concentration of chlorophyll a, b and carotenoid photosynthetic pigments respectively. Based on the correlation analysis (r), a certain dependence could be observed between total and reducing sugars (r= 0.70), total sugars and starches (r= 0.76), reducing sugars and starches (r = 0.79). In the case of photosynthetic pigments, a close relationship between chlorophylls a, b and carotenoids was identified (r= 0.99); In the photosynthetic carbohydrate / pigment interaction, a significant correlation was observed between total sugars and chlorophylls a (r= -0.80), b (r= -0.80) and carotenoids (r= 0.82). The close relationship found between reducing sugars and chlorophyll a (r= 0.60), chlorophyll b (r= 0.99) and carotenoids (r= 0.99) stood out. Implications: it is necessary to continue the study in floral and fruiting stages to have a complete profile of the cultivars. Conclusion: these results will contribute in future agronomic studies of these varieties in the region in order to analyze their relationship with parameters such as yield and nutritional content of fruits.

The mango crop is attacked by various pests, in Arcelia, Tierra Caliente, Guerrero, Mexico. Scale insects (Hemiptera) and thrips (Thysanoptera) were identified, the pesticides imidacloprid, spinosad, sulfur and mineral oil were tested against them, as well as their effect on fruit quality, using pest action thresholds. The thrips Frankliniella invasor appeared in the highest populations, but F. difficilis, F. occidentalis, F. fortissima, F. cephalica, Leptothrips macconnelli, L. bifurcatus and L. theobromae were also found. It was observed that mineral oil maintained the lowest populations and least damage in fruit; thrips species did not cause significant damage because they were seasonal pests that only occur when soft tissue is available in plants and once this tissue becomes unavailable populations diminish without the need of insecticides. The mite Cisaberoptus kenyae was identified, which in high populations can cause crop damage; for its control sulfur yielded better results. The scale Milviscutulus mangiferae was present in very low populations. Treatment with mineral oil resulted in the highest quality fruits.

The prickly pear cactus “tuna pelona” (Stenocereus zopilotensis), is an endemic cactus species from the state of Guerrero, Mexico, it develops in semi-arid areas and has great ecological importance as it houses and forms part of the diet of multiple species in its niche. There is a constant threat to natural populations of this species due to the overexploitation of seedling collections in the field by unregulated trade. In order to design an alternative for the conservation management of these species, the objective of the work was to evaluate treatments for the imbibition of “hairless tuna” seeds to promote germination and the successful establishment of seedlings with economic technologies for the farmers of the area. Fruits of "tuna pelona" (S. zopilotensis) were collected, near the community of Xalitla, municipality of Tepecoacuilco de Trujano, Guerrero; the seeds were stored for 70 and 273 days after collection (dac) at room temperature in order to maintain adequate conditions for the conservation of viability until reaching dormancy. In the stored seeds, the effect of soaking treatments was evaluated: 0, 6, 12, 24 and 12 hours in water plus another treatment that consisted of immersion in a plant-based hormonal stimulant. The germination percentage per treatment was evaluated, it was found that the control treatment (zero hours in water) of seeds stored at 70 dac only obtained 2.4% of germination. The treatment of soaking in water and in the hormonal stimulant both for 6 h presented the highest germination values with 48.6 and 44.4% respectively when using seeds of 273 dac at 14 days after the application of the treatments. These results will allow the massive production of seedlings of the species for reforestation and regional marketing purposes.