Temperature changes, drought, frost, and the presence of pest and diseases place enormous stress on crops, which implies that the potential performance of these crops may be affected. One of the main goals for agronomists, horticulturists, growers, physiologists, soil scientists, geneticists, plant breeders, phytopathologists, and microbiologists is to increase the food production on the same cultivable area and to ensure that they are safe and of high quality. Understanding the biophysical changes in soil will help to manage the crop’s ability to cope with biotic and abiotic stress. Optimization is needed in the nutrition of crops, which involves the use of biostimulants to counter oxidative stress and the management of strain bioformulations (bacteria and fungi) that protect and stimulate roots for the acquisition of nutrients. The implementation of these strategies in fertigation programs improves crop yields. This article addresses the importance of the stimulation and the bioprotection of the root as a fundamental pillar in ensuring the high performance of a crop.

All technological innovation that influences research to achieve yields and counteract biotic and abiotic stress in crops should be a priority for governments and scientists around the world. Silicon nanoparticles (NpSi) in the production and protection of crops are used as a sustainable strategy. In addition to NpSi, other nanoparticles have been applicable in areas such as environmental remediation, medicine and smart sensors. There are plants that accumulate high concentrations of Si in their tissues, such as "horsetail" (Equisetum arvense). A recent analysis of the elemental composition of E. arvense in a cross section, epidermis, and total biomass indicated that the Si concentration was higher in comparison with macro and micronutrients. Elemental mapping showed that all polymerized silicon (SiO2 • nH2O) is available in the epidermis of Equisetum. Currently, our team is investigating the extraction, purification and quantification of SiNp. The lines of emerging research should be those related to the interaction of SiNp in the cell wall, concentration and intelligent application with aerial equipment in crops such as vegetables, cereals, and fruits.

Cherry tomato “Atomic Grape” belongs to the Solanaceae family, an important species due to its economic value and high nutritional content. The impact on performance, weight, and nutritional profile of root, stem/branches, and leaves using the nutrient solution (NS), alone or combined with an organomineral fertilizer (F), whether granulated or in powder form was evaluated: NS, NS + F-granulated, and NS + F-powder. Best commercial fruits were obtained with NS + F-powder. Higher weights of both fresh and dry roots were obtained with NS + F-granulated and NS + F-powder. Mineral profile showed that the root builds up mostly nitrogen and silicon. Potassium was higher in stem/branches. Carbon, calcium, and sulfur were higher in the photosynthetic organ. NS increased the pH of the tomato juice by 9.81% and 10.90% compared to NS + F-granulated and NS + F-powder treatments. The organomineral fertilizer provides greater benefits due to its long-lasting effect on the soil and cherry tomato plant. In this experiment, we conclude that the combination of NS + F-powder obtained the best marketable fruits. It must be taken into consideration the greatest demand for nutrients in tomato given to developing organs such as leaves, flowers, and fruits. The leaves should be used for nutritional diagnosis, to confirm symptoms of deficiency or optimal nutritional ranges, which is of utmost importance for agronomists, growers, horticulturists, and physiologists.

ResumenPolianthes tuberosa L. es una planta endémica de México, comercialmente se cultiva para flor de corte, y, además, es utilizada en la industria farmacéutica y del perfume. Tradicionalmente, los productores la propagan utilizando los cormos, lo que ha ocasionado que el cultivo presente poca variabilidad genética y posiblemente, por esta razón solo se conocen cultivares con flores blancas. Con base en lo anterior el objetivo de la presente investigación consistió en establecer la metodología práctica y competitiva para propagar in vitro Polianthes tuberosa L. Las yemas y pequeños segmentos de tejido de cormo fueron colocadas sobre la superficie del medio de cultivo, base GC (comunicación personal Guillermo Carrillo) con las sales inorgánicas del medio de cultivo Murashige y Skoog (1962) por litro, 50 mL de agua de coco, 20 g de sacarosa, 6.4 g de agar y el pH fue ajustado a 5.7. Con este medio básico se prepararon medios de cultivo que contenían bencilaminopurina (BAP), ácido naftalenacético (ANA), ácido 2,4-diclorofenoxiacético (2,4-D), ácido indolacético (AIA), y cinetina. La formación de brotes que dieron origen a las plántulas ocurrió mediante, la regeneración directa de la yema floral la cual al crecer forma sólo una plántula y a partir del tejido de la base de la yema, de esta región se obtuvieron hasta seis brotes por yema en el medio que contiene BAP, 4.5 mg y ANA, 0.1 mg, del cual la regeneración de brotes fue mayor (56.1 %). En el caso de cormo el problema fue la contaminación llegando en algunos casos hasta el 100 % de los cultivos. Es de resaltar la importancia de poder lograr la regeneración masiva in vitro de plantas de nardo a partir de yemas florales. Palabras clave: Eficiencia de la regeneración, in vitro, contaminación, yemaRecepción: 08-10-2013 Aceptación: 09-07-2014

Tomatoes are one of the main vegetables in the food industry that are consumed fresh and processed. A multi-element microanalysis was performed with the use of scanning electron microscopy (SEM) in conjunction with energy dispersion spectroscopy (EDS), to see changes in nutrient concentration in roots and leaves, as well as fresh and dry biomass in tomato seedlings. Exposed in nutrient solution (NS) with different levels of Ca (control, 25, 50 and 100 mM). The root was put in also to H 2 O 2 for 8 hours to observe the changes that occurred. It was observed that NS with 100 mM Ca in fresh stem biomass and fresh leaf biomass increased by 25% and 38% compared to the control. It was observed that the NS with 100 and 50 mM of Ca, the content of Ca and Cl in foliar tissue increased by 34.50% and 13.15% compared to the control. Treatment with H 2 O 2 and with 25 and 100 mM of Ca at NS increased the height of the seedling and fresh leaf bio-mass by 19.75% and 60.80% compared to the control. The treatment with H 2 O 2 and with the different levels of Ca in the NS increased the content of C, P, K, Ca and Cl in the leaf tissue. Only S was significant for the control. Treatment with H 2 O 2 and 100 mM Ca in the NS increased Ca and Mg by 83.48% and 40.47% for the root compared to the control. The K and Cl in the root was higher in the control treatment by 47.61% and 55% respect to the highest level of Ca. It is concluded that multielemental microanalysis is a powerful, non-destructive, fast and accurate tool for the determination of plant nutrients.