Soil microorganisms play an important role as a link in the transfer of nutrients from the rhizosphere. The physical and chemical properties of soil, the metabolic profiles of microbial communities and different crop management practices can enhance our understanding of rhizospheric interactions. This study aimed to establish differences in microbial communities associated with banana crops and the biochemical profile in farms under different agronomic conditions. Seven farms with different levels of intervention, management, and fusariosis severity were analyzed. The biochemical profile of the microbial community was determined using EcoPlates and the main substrates consumed by the microbial communities were identified through multivariate principal component analysis (PCA). Seven microorganisms were selected as indicators of nutrient cycles, pathogenicity and soil health. Also, soil chemical indicators were determined through a complete mineral analysis. For the physiological profile of soil microbial populations, it was observed that farms with the same management tend to be metabolically very similar. In the PCA, two principal components explained 90 % of the variance in the data. It was also determined that the genus Bacillus is predominant in all farms and that farm 4 (medium intervention) presented the most favorable values in all factors analyzed. The effective cation exchange capacity values are highlighted in the chemical analyses, which determined that all farms have a high fertility level. The metabolic profile, diversity and richness of each of the different farms were affected by the type of agronomic management used.

By managing tomato at a high population density, blunting to the third cluster and transplanting 40 days after sowing (das), the transplant to end-of-harvest cycle lasts four months, achieving three cycles per year and a potential yield of 500 t∙ha^-1-2 for 25 mL, and 300, 200, 150 and 75 seedlings∙m^-2 for 250 mL) were evaluated.A split-plot randomized complete block design with four replicates was used. Morphological variables, number of flowers and yield were recorded. Analysis of variance and comparison of means (Tukey, P ≤ 0.05) were performed. Seedlings with morphological characteristics suitable for transplanting at 60 das were those grown in 250 mL cavities at densities of 75 and 150 seedlings∙m^-2. Cavity volume and seedling density did not influence the number of flowers or fruits per plant.

Pepper wilt, caused by Phytophthora capsici, is one of the main threats faced during pepper production. Therefore, this study aimed to evaluate the effect of Streptomyces spp. in the biological control of P. capsici under in vitro and in vivo conditions. The in vitro antagonistic activity of strains ABV38, ABV39 and ABV45 was examined by means of dual confrontation tests. Broth culture supernatant (BCS) from the growth of the strains was irrigated on pepper plants inoculated with P. capsici CH11 (PC CH11) to evaluate wilt suppression. Molecular identification of the strains was carried out by analyzing the partial sequence of the 16S rRNA gene. Under in vitro conditions, strains ABV38, ABV39 and ABV45 inhibited the mycelial growth of PC CH11 by 51, 28 and 50 %, respectively. In the in vivo evaluation, the BCSs of strains ABV38 and ABV45 showed a wilt suppressive effect, with plant survival of 77 and 94 %, respectively. Strain ABV39 did not show a wilt suppressive effect (0 % survival), and nor did the untreated plants. Molecular identification indicated that strains ABV39, ABV38 and ABV45 belong to the genus Streptomyces, of which ABV38 and ABV45 have potential for biorational control of pepper wilt.

Coffea arabica L. faces serious disease susceptibility problems, favored by the low genetic variability of its commercial cultivars; therefore, it is important to study different sources of variation that are useful in genetic improvement. The objective of this study was to irradiate C. arabica-1 seeds of the Geisha, Oro Azteca and Marseillaise varieties with gamma rays to determine the median lethal dose (LD₅₀) and evaluate their physiological response in terms of germination, survival, plant height (PH), stem diameter (SD), height to first leaf pair (HFLP) and leaf area (LA). The Transelektro LGI-01 irradiator was used, with a dose rate of 752.76 Gy·h^-1. The irradiation doses evaluated were 0, 100, 200, 300, 400 and 500 Gy. The experiment was established under a completely randomized factorial design with two factors (variety, with three levels, and irradiation dose, with six levels) and three replicates (225 seeds per replicate). The germination record was made 20 days after sowing. The remaining variables were evaluated 120 days after sowing. The results showed that germination, survival, PH, HFLP, SD and LA were significantly negatively affected by gamma irradiation from the 200 Gy dose in all three varieties. The LD₅₀ was 70 Gy for the Geisha variety, 85 Gy for Marsellesa and 90 Gy for Oro Azteca. Doses lower than 100 Gy can be used in breeding programs for C. arabica-1.

Avocado is the third most produced crop in the State of Mexico, with 11,296 ha, where the predominant variety is ‘Hass.’ Due to a lack of knowledge about its development in different environments, its agronomic management is highly heterogeneous, since it is based on experiences in other states. The objective of this study was to analyze, describe and quantify the phenological development of ‘Hass’ avocado in three environments in the State of Mexico. The vegetative, flowering, root and fruit development of ‘Hass’ avocado was recorded during the 2011-2012 cycle. Two periods were distinguished for vegetative growth (December-April and October-November), flowering (December-February and August-October), harvest (November-February and August-October) and root growth (April-July and October-December). The vegetative growth (0.40 and 0.06 cm increase in shoot length and diameter, respectively) and root growth (36 and 24 g fresh weight and dry matter, respectively) were lower than fruit growth (70.1 mm increase in diameter) in Coatepec Harinas (temperate with andosol soil and isotherms from 14-18 °C). In contrast, the same growth measurements were higher in the localities with cambisol-luvisol soil and isotherms from 16-20 °C: Ixtapan del Oro (temperate/semi-warm, with 0.69 and 0.12 cm in shoot, and 56 and 48.8 g in root) and Temascaltepec (semi-warm, with 0.78 and 0.23 cm in shoot, and 69.3 and 31.3 g in root), but lower increases in fruit (59.4 and 56.6 mm, respectively). The phenological differences observed among environments will be useful for the technical management of the crop.