Efficient detection of nutrient deficiencies and development of corrections in avocado through the Compositional Nutrient Diagnosis (CND)

Mexico is the main producer of avocado (Persea americana Mill.), contributing 31% of the world supply, which provides the country with an annual income of more than 2 billion dollars. The increase in national production is the result of a larger cultivated area, and not an increase in yields. In the State of Mexico, Mexico around 10 thousand hectares are cultivated with avocado trees, although 77% of the producers do not have specialized technical advice that offers reliable information on crop nutrition. This lack of advice and technical support detracts from volume and quality of production. The objective of this research was to carry out the nutritional diagnosis of an avocado orchard in Tejupilco, State of Mexico, Mexico, through the Compositional Nutrient Diagnosis (CND), and to generate specific fertilization recommendations for the study area, for which leaf and soil analyses were carried out. Each nutrient determined in the leaf analysis (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and B) was compared with its optimal concentration according to literature. The CND yielded relative deficiency or excess indices that determined the order of nutritional limitation. Zn, B, S, and K deficiencies were detected in all sampled areas, while P, Mn, and Cu were deficient only in some areas. N, Ca, Mg, and Fe did not show nutritional limitation. Recommendations were formulated to address each of the nutritional deficiencies and the problem of sodicity revealed by the soil analysis. This is the first work in which the CND is used to assess the nutritional situation of avocado orchards in the world

Nitrogen form and root division modifies the nutrimental and biomolecules concentration in blueberry (Vaccinium corymbosum L.)

Blueberry (Vaccinium corymbosum L.) continues to gain importance in the international market due to its effects on the prevention of human diseases. This leads to the need to optimize the production and quality of the fruit. The present research evaluated the effect of NO3- and NH4+, using the split roots technique, in the nutritional status, photosynthetic pigments and total sugars in blueberry leaves. A completely random experiment was established with six greenhouse treatments: three under homogeneous root conduction (HR) and three with split roots (SR). The concentration of N, P, K, Ca, Mg, S, Fe, Cu, Zn, Mn, B and Na, chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoids (Car) and total sugars were evaluated in the leaves. The exclusive supply of NH4+ led to the largest accumulation of N, P, Mg, S, Cu, Mn and B, compared to plants treated with NO3-. The Chla and total sugars were higher with NH4+ compared to NO3- nutrition. The supply of N separately (SR) had no positive effects on the evaluated variables, however, the SR with half of N, in the form of NH4+, compared to the non-SR with full application of N, has no differences in N-leaf concentration, which implies a higher use in the uptake or accumulation of this macro element in plant. V. corymbosum L. with split root and half of N in the form of NH4+, doubled the N use efficiency, as it matches in yield the complete supply treatment of N-NH4+ without root division

Effect of titanium foliar applications on tomato fruits from plants grown under salt stress conditions

Salt stress affects plant metabolism, while beneficial elements such as titanium (Ti) may stimulate adaptive responses to mitigate salt stress. Here we evaluated the main effects of sodium chloride (NaCl 0, 50 and 100 mM) in the nutrient solution, and of titanium foliar spray (Ti 0.75 and 150 mg L-1), as well as the interaction of these study factors, on tomato cv. ‘Rio Supremo’ performance in greenhouse. Plants were treated with NaCl during 80 d through automated drip irrigation; while eight Ti foliar sprayings were applied with a manual sprayer, at intervals of 10 d each. Yield and quality parameters of fruits were evaluated in the second cluster. NaCl reduced yield parameters, pH value and increased the titratable acidity (TA), electrical conductivity (EC), and total soluble solids (TSS), as well as the TSS/TA ration in the fruits. Ti did not affect yield parameters, though it reduced the pH and increased the TSS/TA ratio of fruits. NaCl and Ti have differential effects on fruit quality as separate factors, while the interaction of both factors revealed that Ti effects dependent on the presence of NaCl and its level in the nutrient solution. In conclusion, Ti did not mitigate the negative effects of saline stress on the evaluated yield parameters, but importantly, with moderate levels of NaCl in the nutrient solution (50 mM), Ti increased EC, TA and TSS of fruits

Biostimulant effects of lanthanum (La) on crop growth, yield, and quality

Objective: To analyze the various effects that the use of La as an inorganic biostimulant has on growth, yield and quality of different crop plants. Design/methodology/approach: A search in recent literature related to the effects of lanthanum on various economically important crops was conducted. Subsequently, the most relevant information was selected, analyzed and grouped by type of effect. Results: The addition of lanthanum at low doses has been tested in different crop plants. It has been proven that La increases growth, development and quality in various species. Likewise, positive effects have been reported in germination, in the absorption of nutrients, in mitigating the deficiencies of some essential elements, as well as in the promotion of physiological and biochemical responses. Limitations/implications of the study: The analyzed results have been generated in a great diversity of plant species, under different production systems, with dissimilar doses, as well as with different sources and application methods. This situation represents a challenge, since it hinders the possibility to issue general recommendations. Findings/conclusions: Lanthanum improves yield and quality, as well as some physiological, biochemical and nutritional responses in different crops of economic importance

Biosynthesis of Silver Nanoparticles Using Chenopodium ambrosioides

Biosynthesis of silver nanoparticles (AgNPs) was achieved using extract of Chenopodium ambrosioides as a reducer and coating agent at room temperature (25°C). Two molar solutions of AgNO3 (1 mM and 10 mM) and five extract volumes (0.5, 1, 2, 3, and 5 mL) were used to assess quantity, shape, and size of the particles. The UV-Vis spectra gave surface plasmon resonance at 434–436 nm of the NPs synthesized with AgNO3 10 mM and all extract volumes tested, showing a direct relationship between extract volumes and quantity of particles formed. In contrast, the concentration of silver ions was related negatively to particle size. The smallest (4.9 ± 3.4 nm) particles were obtained with 1 mL of extract in AgNO3 10 mM and the larger amount of particles were obtained with 2 mL and 5 mL of extract. TEM study indicated that the particles were polycrystalline and randomly oriented with a silver structure face centered cubic (fcc) and fourier transform infrared spectroscopy (FTIR) indicated that disappearance of the –OH group band after bioreduction evidences its role in reducing silver ions

Silicon and titanium affect the percentage of juice and color attributes in tomato fruits of plants exposed to salt stress

Objective: To evaluate the leaf application of silicon (Si) and titanium (Ti) in three doses (0, 75, and 150 mg L-1), independently, on tomato plants cv. Río Supremo, subjected to saline stress (0, 50, and 100 mM NaCl), on the percentage of juice and color attributes of the fruit. Design/methodology/approach: Two independent essays were carried out under a completely randomized experimental design in a 32 factorial arrangement, where the first study factor was the NaCl concentration in the nutrient solution and the second factor was the leaf application of Si or Ti. The percentage of juice and color attributes in fruits were determined. An analysis of variance and the comparison of means by Tukey (p ≤ 0.05) with the SAS software were performed. Results: Salinity was found to reduce the percentage of juice, the color index, and the ratio of “a/b” indexes. Regarding the interactive effects, NaCl with both Ti and Si increases the “b” index. Leaf applications of Si increased the “b” index and reduced the percentage of juice, the color index, and the ratio of “a/b” indexes. Also, Ti improved the color index and the “b” index. Limitations of the study/implications: The results were obtained in the Río Supremo tomato variety under greenhouse conditions. Other varieties should be tested too. Findings/conclusions: Si and Ti applied to the leaves have positive effects on the color of the fruits of tomato plants under saline stress

Exploitation of plantain (Musa spp.) plantations as an agrotourist element

Objective: To publicize the processes and alternative uses that plantain cultivation may have, in addition to places with tourist potential in the town of Monte Salas, Fortín de las Flores, Veracruz, Mexico Design / Methodology / Approach: A methodology based on stages was carried out where a compression of the space of the study area was made, anthropological analysis, description of the process of the banana leaf, commercial analysis, development of a sustainable product and a bonding stay in the country of Colombia Results: In the town of Monte Salas, Fortín, de las Flores Veracruz, Mexico, plantain cultivation was analyzed as an outstanding element of the landscape, together with the process of leaf roast production as a value-adding strategy to generate biodegradable co-products. Through the dissemination of audiovisual capsules on social networks, places with tourist potential were made known and together with the implementation of the offer of biodegradable co-products, it was demonstrated that banana leaf can be used alternately. Study limitations / implications: Due to the health contingency experienced, it was not possible to carry out a workshop programmed for the locality. Conclusions: Making it known that new products can be created that are biodegradable and that have no impact on the environment brought with it the acceptance of creating the dishes made with the leaf, and also its successful implementation in the tourist field I believe the possibility for tourists to come to the town of Monte Salas, Fortín de las Flores, Veracruz, Mexico to discover its agro-systemic landscape.Objective: To analyze the processes and alternative uses that plantain cultivation may have, in addition toplaces with tourist potential in the town Monte Salas, municipality of Fortín de las Flores, Veracruz, Mexico.Design/Methodology/Approach: A review of the space of the study area was performed, as well as ananthropological analysis, description of the process of the plantain leaf used to prepare local food, commercialanalysis, development of a sustainable product, and a research stay in Colombia.Results: In Monte Salas, Fortín de las Flores, Veracruz, Mexico, plantain cultivation is regarded as anoutstanding element of the landscape, together with the process of leaf roast production as a value-addingstrategy to generate biodegradable co-products. Through the dissemination of audiovisual capsules on socialnetworks, places with tourist potential were made known and together with the implementation of the offer ofbiodegradable co-products, it was demonstrated that plantain leaf can be used alternately.Study Limitations/Implications: Due to the SARS-CoV-2 (COVID-19) coronavirus pandemic, the dissemination of our findings and products were restricted.Conclusions: Novel biodegradable products can be manufactured from plantain leaves, which created aspecial interest of local tourists to visit Monte Salas and enjoy the agrosystemic landscape

Silicon increases seed weight and initial seedling growth of maize under non-stress conditions, and improves the index of velocity of germination under salt stress conditions

Salinity is one of the most critical factors affecting agriculture worldwide. The application of beneficial elements like silicon (Si) is one of the alternatives to mitigate its effects. In this research, we evaluated the effect of Si applied during seed imbibition on mitigating the negative effects caused by salinity during the germination and initial growth phases of maize (Zea mays L.) SB-308 seedlings. Seed pre-treatment during the imbibition was made with 0.0-, 1.5- and 3.0-mM Si. Afterwards, seeds that were imbibed were placed in plastic containers and treated with 0, 80, 160, and 240 mM NaCl. The evaluated concentrations of Si and NaCl gave rise to 12 treatments. Pre-treated seeds with 3 mM Si had an increase of weight after imbibition, 5.1% higher than the control. The treatments obtained from combining NaCl and Si levels did not affect the total and relative germination. The radicle length increased by 13.6% with 3 mM Si compared to the control. Conversely, it was lower with increasing salinity. These trends were observed in plant height. The interaction of the study factors produced an increase in the radicle length in the interval from 0 to 160 mM NaCl, when the Si dose was increased. However, there were no significant differences among equal levels of salinity without Si. It is concluded that Si increased the absorption of water during the imbibition and raised the index of velocity of germination under salinity, except in the dose 240 mM NaCl. Likewise, the pre-treatment of seeds with Si tends to increase radicle length under saline conditions