In seed technology, the use of biocompatible materials, such as chitosan, has been demonstrated to improve the germination process and establishment of seedlings. This research is focused on the effect of a chitosan coating on the germination and development of sesame and bean plantlets. The seeds were treated with different coating techniques and combinations of chitosan: chitosan solutions at 0.1, 0.5 and 1% were used in film coating, chitosan flakes with particle sizes of 1.19 mm and 0.71 mm were used as a crusted coating, and chitosan flakes with a size of 1.19 mm were used for coating with acrylic resin. Images of the coatings were obtained by means of scanning electron microscopy; the effect on germination, germination speed, vigor index, length and root area of plantlets were also determined. Chitosan treatments increased germination by 26% in bean and 16% in sesame compared with the control; the germination speed index showed an increase of 61% in bean and 58% in sesame. The treatments with chitosan increased the length of the root in bean by 77%, and in sesame four times more, compared with the control treatments. Different forms of chitosan coatings improve germination and seedling establishment; however, the response to the type of coating at a given stage of seedling development will depend on the crop species.

Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.

In Guanajuato, Mexico, water deficits have dramatically increased in recent years due to over-exploitation of this resource. The objective was to identify high yielding wheat (Triticum spp.) varieties under two irrigation regimes. The experiments were planted at Celaya, Guanajuato, for two consecutive (2013-2014 and 2015-2016) growing seasons (GS). Eleven commercial varieties and nine experimental lines were evaluated under 3 or 4 irrigation regimes; split-plot design with 4 replicates was considered; data on yield performance and its components were measured. There were significant differences between GS and number of irrigation regimes (p ≤ 0.01) for most evaluated traits. ANOVA showed significant differences for all traits in the study, except for the 1000-grains weight. Growing seasons affected yield, grains number m^-2 and biomass, mainly; on last cropping season, grain yield was higher (1.8 t ha^-1) than first one; strong gluten genotypes were more stable, as compared with the soft gluten genotypes. Some experimental varieties exceeded commercial varieties, which means success in wheat breeding. Genotypes Experimental Line D and control ‘Bárcenas F2002’ under 3 irrigations regime treatment showed the highest grain yield (7.7 and 7.0 t ha^-1, respectively). On 4 irrigations regime, the best yielding genotypes were experimental lines D, and H, with 6.5 and 6.1 t ha^-1, respectively. Based on regression deviations the most stable and predictable wheat genotypes were strong gluten genotypes.

Rhus aromatica inhabits humid oak and oakpine forests in the State of Michoacán (Mexico). The fruit of R. aromatica is edible and is traditionally used in the preparation of soft drinks, ice pops, ice creams and 'atole'. The objective of the present investigation was to carry out a physical and chemical characterization and analysis of the antioxidant capacity of fruit. For the physical characterization, the equatorial and longitudinal diameter, weight and percentage of pulp were determined. In the chemical characterization, a proximal analysis was carried out, quantification of polyphenols and flavonoids was performed, and the antioxidant capacity was determined. The results showed that the fruit had a longitudinal diameter of 6.58 ± 1.02 mm, an equatorial diameter of 7.17 ± 0.66, a weight of 55.22 ± 5.47 mg, and a 40 % pulp proportion. The chemical characterization analysis indicated 8.7 % moisture, 30.6 % lipids, 8.7 % proteins, 29.4 % total sugars, 3.8 % ashes and 18.7 % crude fibre, 3.1 °Brix, pH 3.1, 1.92 % acidity total and a caloric intake of 4.27 kcal/g. The polyphenol content was higher in 60 % ethanol extracts with 88.6 ± 50.89 mg EAG/g; for flavonoids from extracts with 100 % acetone, it was 26.52 ± 0.65 mg EQ/g, and the total carotenoid content was 46.37 mg/100 g. The total antioxidant activity was higher in extracts with 80 % acetone, with 87.17 % inhibition of the DPPH radical and 90 % inhibition of ABTS without showing a significant difference with the different solvents used. The lowest IC₅₀ values were presented in 100 % ethanol and 60 % methanol extracts for the DPPH radical and for the ABTS radical were the 80 % ethanol and 60 % methanol extracts. The lipid, protein, carotenoid, and polyphenol contents and antioxidant capacity of the fruit of R. aromatica were as high as those of other fruits consumed in the human diet.

Las bacterias patógenas son responsables de grandes afectaciones en los principales cultivos, causan desde daños moderados hasta pérdida total. En plantas de ajo cultivadas durante el ciclo otoño-invierno 2016-2017 en dos localidades, Celaya e Irapuato (estado de Guanajuato, México), se detectaron síntomas de estrías amarillas en el margen de la hoja desde los dos meses después de la siembra. El objetivo de este trabajo fue aislar e identificar los agentes causales asociados a estos síntomas. A partir de 62 muestras de follaje con manifestaciones características de la enfermedad en tres materiales de ajo, se obtuvieron 74 aislados bacterianos puros y se seleccionaron los 13 más representativos, según su morfología colonial, que fueron identificados molecularmente por amplificación y secuenciación del gen ribosomal 16S. Para la localidad de Celaya se identificaron las especies Pantoea agglomerans, Bacillus amyloliquefaciens, Erwinia persicina, Bacillus megaterium y Bacillus mojavensis y para Irapuato Bacillus aryabbattai, B. amyloliquefaciens, B. megaterium, Erwinia persicina. Estas bacterias resultaron ser de importancia fitosanitaria en la fase de desarrollo vegetativo y formación de bulbo, pues se lograron recuperar a partir de tejido dañado obtenido de plantas previamente inoculadas. Hasta donde se sabe, este es el primer reporte de la presencia de dichas bacterias relacionadas con los síntomas descritos en cultivos de ajo y con el deterioro de los bulbos durante su almacenamiento poscosecha.

Germination is a process of high metabolic activity in plants that involves the use of storage components present in seeds for seedling development. Chemical induction is a process in which different types of compounds are used to promote the activation of secondary metabolic pathways. The objective of the present study was to determine the effect of chemical induction with salicylic acid (SA) (1 and 5 mM) on chickpea seed germination, germination percentage, radicle length and protein content in seedlings. Soluble protein fractions and trypsin inhibitory activity were quantified in the seedlings, and protein patterns were identified by polyacrylamide gel electrophoresis. Treatment with 5 mM salicylic acid decreased both the germination percentage and the length of the radicle. The albumin fraction content of the seedlings was reduced with 1 mM SA. The trypsin inhibitory activity in the globulin fraction decreased in seedlings treated with both SA treatments. Protein electrophoretic patterns from SA-induced seedlings remained similar to those without induction. In a dose-dependent manner, chickpea seedlings exhibited changes in seedling development, concentration of protein fractions, and reduced trypsin inhibitory activity.