Agro Productividad

Determination of Combinatorial Ability and Heterosis in Capsicum chinense Jacq., using Line × Tester Analysis Method

2024-11-11T17:24:03+00:00

Objective: Know the combinatory ability and heterosis in yield parameters and fruit quality, in nine genotypes of Habanero Chilli (Capsicum chinense Jacq.).

Design/methodology/approach: In order to know the combinatory ability and heterosis in yield parameters and fruit quality, were crossed nine genotypes of Capsicum c hinense Jacq. (Habanero Chilli) in a Line × Tester (7 × 2) mating design. The parental lines and combination of crosses were evaluated in a randomized complete block design with three replications at the Yucatan Scientific Research Center during the 2018 and 2019.

Results: The results showed the lines 3 and 7, presented a high and positive general combinatory ability (GCA) for most of the parameters studied, the tester 1 presented a high GCA for yield per plant (YP) with 0.45. The cross L1 × T2 presented the highest value of specific combining ability (SCA) for YP with 0.50. The highest heterosis (171.01%) was observed in the L1 × T1 cross for capsaicin content (CC). Tester 1 was identified as a promising genotype for breeding Capsicum chinense Jacq.

Findings/conclusions: Line 7 and Tester 1 was identified as promising genotypes for crop breeding Capsicum chinense Jacq.

Effect of branch girdling on the alternate bearing, yield, and fruit quality of grapefruit (Citrus paradisi Macf.)

2024-11-11T17:25:30+00:00

Objective: The objective of this research was to evaluate the effect of girdling branches, application of gibberellic acid (GA₃), and foliar urea on the alternating yield and quality of grapefruit (Citrus paradisi Macf) fruits.

Design/methodology/approach: The experiment was carried out on trees during abundant harvest (“on” year) and trees with low harvest (“off” year). Foliar applications of GA₃ and foliar urea were performed with a manual sprayer at a rate of 7 L tree^-1 of solution. Branch girdling (5.0 mm wide) was performed on two-thirds of the secondary branches using a circular-edged knife to avoid damaging the xylem. The experimental design was completely randomized, with 2⁴ factorial arrangements with 16 treatments and 3 repetitions. Each experimental unit was a tree to evaluate fruit yield and quality at the experiment's conclusion.

Results: Branch girdling increased the diameter, the number of fruits, the yield, and the ºBrix-Acidity ratio of the juice. Foliar urea applications increased the percentage of juice but delayed ripening. The combination of branch girdling plus foliar urea applications increased fruit weight. The yield increase was attributed to the number of fruits rather than their weight. The treatments did not reduce alternate bearing.

Limitations on study/implications: The commercial cultivation areas for the experiment were limited due to the availability of facilities for testing fruit quality.

Findings/conclusions: To increase the size and number of fruits, with an increase in yield, branch girdling is an effective option. Furthermore, the application of foliar urea increases the percentage of juice and fruit weight, with a slight delay in maduration. However, the treatments did not reduce alternate bearing. Future research is required with other grapefruit varieties at different application times.

Impact of planting density and nitrogen on the productivity of warm-climate onion in the Mexican pacific

2024-11-11T17:26:31+00:00

Objective: To evaluate three population density and nitrogen supply in onion.

Design/methodology/approach: An experiment was developed in the dry tropics of Mexico. Seedlings were produced in nursery and transplanted on 0.9 m planting beds. In addition to crop management with drip irrigation, nitrogen nutrition was planned according to the rational form of supply. Density/nitrogen factors were evaluated in factorial design 3². Developmental, productive and qualitative bulb variables were recorded and statistically analyzed.

Results: The interaction of factors was varied, but in the productive, only the density factor was consistent; bulb weight excelled in the low density (14.8 plants m²) but did not lead to the highest yield, on the other hand, the highest density together with N supply, presented the highest yield per area of 2.14 and 2.17 kg m².

Limitations on study/implications: Onions are favored by the Mexican population as they are among the most consumed vegetables due to their bulbs, and they are attributed with various health benefits. Approximately 52 thousand hectares are harvested in the country and Michoacan participates with 8.3% of production. However, yields are lower than their potential, due to the lack of adaptation to current environmental conditions. This leads to consider the exploration of alternative locations and the implementation of strategies to improve yields, where nutrition and spacing are key factors.

Findings/conclusions: The density of 26.9 plants m² with N addition produced the highest yield.

Alternative Solution to Estimate Cucumber Crop Evapotranspiration in Shade Nets for the Valle de Culiacán, Mexico

2024-11-11T17:27:27+00:00

Objective: This work aimed to estimate the evapotranspiration of cucumber crop grown in a shade house in Valle de Culiacán, México.

Design/methodology/approach: The FAO56 method was used with a variation of the FAO Penman-Monteith equation, and a non-conventional evaporimeter to measure evaporation inside the shade house. Using the estimated reference evapotranspiration and the measured evaporation, pan coefficients were calculated, and a mathematical model was proposed to calculate this coefficient based on the meteorological parameters: air temperature, relative humidity, and net solar radiation.

Results: The estimated crop evapotranspiration was 417.6 mm. The linear regression between the reference evapotranspiration estimated with FAO56 and calculated with evaporation and adjusted evaporimeter pan coefficient yielded excellent statistical estimators (R²>0.9).

Findings/conclusions: The analysis of the evaporimeter pan coefficient's dependence on meteorological parameters indicates a strong dependence on air temperature, net solar radiation, and vapor pressure deficit, but not on relative humidity.

Effectiveness of Chemical Fungicides for the in vitro Control of Fusarium spp. Causing Basal Rot in Onion in Sinaloa, Mexico.

2024-11-11T17:28:27+00:00

Objective: Identificar la efectividad in vitro de cinco fungicidas químicos, y el porcentaje de inhibición de crecimiento micelial de F. falciforme, F. brachygibbosum y F. oxysporum en la producción de cebolla.

Design/methodology/approach: Los aislamientos se sometieron a una prueba de sensibilidad in vitro de cinco fungicidas con concentraciones de 1, 10, 100 y 1000 ppm en medio de cultivo PDA. Se transfirieron discos de 0.5 cm de diámetro de los aislamientos al centro de caja Petri que contenían el medio de cultivo impregnado con los fungicidas. Se estableció un diseño completamente al azar con cinco tratamientos y un testigo, con tres repeticiones por concentración. Se midió el crecimiento micelial y se calculó el porcentaje de inhibición de crecimiento micelial.

Results: Se observó diferencia en el porcentaje de inhibición del micelio entre los fungicidas y las especies siendo tubeconazole el más efectivo. Además, se encontró que, a mayor dosis de fungicida, el porcentaje de inhibición micelial disminuye. El fungicida más efectivo para F. falciforme y F. brachygibbosum fue boscalid y verango a bajas concentraciones, y tubeconazole y tiabendazol a altas concentraciones. Para F. oxysporum boscalid y verango fueron más efectivos a bajas concentraciones.

Findings/conclusions: En general, F. oxysporum mostró una mayor sensibilidad a todos los fungicidas.

Light Quality Produced by LED Combinations on the Growth of Cucumber Seedlings (Cucumis sativus L.)

2024-11-11T17:44:50+00:00

Objective: To determine the influence of light quality on the growth of cucumber plants (Cucumis sativus L.), through the intensity of expression of different characteristics.

Design/methodology/approach: A completely randomized block design was used with four treatments and 10 repetitions. The treatments consisted of combinations of white (B), red (R) and blue (A) LEDs placed in growth chambers, with percentages of: 100B-0R-0A, 70B-30R-0A, 80B-0R- 20A and 60B-27R-13A, growth chambers with LED-based lighting systems lamps were used. Seeds of the 'Top 1056’ cultivar, Persian type, were sown. The response variables evaluated in the cucumber plants were plant height, stem diameter, leaf greenness, leaf area, fresh and dry biomass of leaves, stem and root of the plants.

Results: The light spectrum emitted by the LEDs influenced the morphology of the cucumber seedlings. With the 80B-0R-20A treatment, where there was greater blue light emission, greater leaf greenness and stem diameter were achieved. In contrast, the 70B-30R-0A treatment, with more red light, increased plant height and leaf area. Fresh and dry biomass of leaves and stem were also modified by light quality. Plants grown in the 70B-30R-0A treatment produced the greatest amounts of fresh and dry biomass, both stem and leaves.

Limitations on study/implications: The use of artificial lighting systems, with different spectral compositions for production in controlled environments presents a viable opportunity to enhance crop growth. Therefore, it is important to investigate how the light spectrum of different LED combinations affects the growth of cucumber seedlings.

Findings/conclusions: The light spectrum emitted by LED combinations influenced the morphology of cucumber seedlings, since with 80B-0R-20A treatment, resulted in greater leaf greenness and stem diameter, while the 70B-30R-0A treatment increased the height and leaf area of the plants.

Cabbage plant (Brassica oleracea var. capitata L.) quantification culti-vated under different soil covers using aerial photographs

2024-11-11T17:46:07+00:00

var. capitata L.) quantification cultivated under different types of mulching, using aerial images captured by RPAS (Remotely Piloted Aircraft System).

Design/methodology/approach: The cabbage plantation used for the study was established under a completely randomized block design with different types of mulch as treatments: black plastic, white plastic, straw, and bare soil. Manual plant counts and automated estimates were performed using two agricultural artificial intelligence platforms (Platforms A and B). The relationship was evaluated using linear regression correlation (R²), and the following indicators were subsequently used: estimation accuracy (Ps), estimation error percentage (Es), mean absolute error (MAE), and root mean square error (RMSE).

Results: Platform A showed a correlation coefficient range of R²=0.41 to 0.91. Platform B obtained R² values ranging from 0.77 to 0.88. Platform A exhibited the highest estimation accuracy (Ps) with 98.3% and an estimation error (Es) of -1.7% for straw mulch, with a mean absolute error (MAE) of 2.0% and a root mean square error (RMSE) of 1 for bare soil. Both platforms showed underestimations in the number of detected plants, ranging from -6.7% to -1.7%.

Limitations on study/implications: The use of RPAS was limited by atmospheric conditions such as wind and rain.

Findings/conclusions: The effectiveness of counting cabbage plants using RPAS was validated.

Commercial amino acids for yield and its components of common bean Azufrado Reyna in Northern Sinaloa

2024-11-11T17:47:10+00:00

Objective: To investigate the effect of foliar commercial amino acids on yield and its components of common bean Azufrado Reyna under field conditions.

Design/methodology/approach: Randomized complete block design with four replicates and four treatments (three commercial amino acids and a control). Grain yield, aboveground biomass, number of pods and normal seeds per unit surface, number of grains per pod, number of normal seeds per pod, weight of 100 seeds, and individual weight of seed were evaluated.

Results: All biostimulants influenced the increase in grain yield, aboveground biomass, number of normal pods and seeds per unit surface as well as the number of seeds per pod with respect to the control.

Limitations on study/implications: The study only assessed the evaluation of agronomic variables; therefore, it is necessary the measurement of morpho-physiological traits that provide evidence about the benefits of foliar aminoacids on yield and the formation of each component under field conditions.

Findings/conclusions: Foliar biostimulant application had a positive effect on grain yield and some of its components as compared to the control. The number of normal seeds per normal pod was the variable that showed the highest correlation with grain yield.

Relationship between Vegetation Indices and Pinoxaden Toxicity in Two Populations of Avena fatua L.

2024-11-11T17:48:14+00:00

Objective: To study the relationship between vegetation indices and the toxicity of the herbicide pinoxaden on two populations of Avena fatua L.

Design/methodology/approach: A completely randomized design with a 2x4 factorial arrangement was used in the laboratory, with factor A being the two populations of Avena fatua and factor B being the four concentrations of the pinoxaden herbicide (0, 30, 60 and 120 g a.i. ha^-1). The percentage of control, plant height and the GA and GGA vegetation indices were evaluated. The data were analyzed with an ANOVA and a comparison of means was performed with the Tukey test (α=0.05). The relationship between the control percentage and vegetation indices was determined by Pearson correlation analysis.

Results: There was a higher percentage of control, plant height, GA index and GGA index in the Avena fatua population from alfalfa compared to the wheat population, indicating that pinoxaden has greater phytotoxicity for the alfalfa population. A negative correlation was observed between the control percentage and the GA index for the two populations regardless of the evaluation time, a similar negative correlation was found for the GGA index in both populations. This indicates that the GA and GGA indices decrease as the control percentage increases.

Findings/conclusions: The GA and GGA indices were inversely correlated with the control percentage of the herbicide pinoxaden. The GA and GGA indices obtained through digital camera images are feasible to estimate the toxicity levels of the herbicide pinoxaden.

Endophytic Mycorrhiza-mediated Phytogen resistance in plants

2024-11-11T17:49:25+00:00

Objective: Mycorrhizal fungi are a group of microorganisms that live insithusants, thus, maintaining perceptible associations with their host plants in certain parts of their life cycle. They can be characterized by their capacity to synthesize secondary metabolites and to promote growth and induce plant-disease resistance, therefore, gaining greater biotechnological importance in pest and diseases management for crops of agricultural relevance. The study of these microorganisms has been a widely researched area subject for more than half a century. Design/methodology/approach: Their biology and molecular relationships in plant-microorganism interactions, on the other hand, have only recently begun to gain relevance for understanding the colonization process in recent decades. There has been observed a complexity in the generation of formulations that can guarantee the permanence of fungi outside the host plant. Findings/conclusions: This review article will address topics related to their biology, ecological role, possible negative effects on commercially important animals, and successful cases in Mexico regarding biotechnological products based on these microorganisms.

Assessment of Harvest Losses in Mejhoul Date Variety in Northwest Mexico

2024-11-11T17:50:50+00:00

Objective: To assess date losses during harvest and identify the factors causing them.

Design/methodology/approach: A complete randomized block design with ten repetitions was used; the different farms where data on the evaluated variables were taken were the treatments. In each treatment, 10 plants were selected from which data on average fruit weight, polar and equatorial fruit diameter, fruit weight, number of clusters per plant, and yield in tons per hectare were taken.

Results: For yield in tons per hectare of good fruits during the date harvest in the 2023 cycle, an average of 11 t ha^-1, 14 t ha^-1, 8 t ha^-1, and 15 t ha^-1 was found for the plantations of El Pólvora, El Pino, Las Palmas and Cucapah respectively. In losses during the harvest, Cucapah Farm presented the highest losses with an average of 1.2 t ha^-1, while El Pino was the one that presented the lowest losses with an average of 0.7 t ha^-1. Fruits with a percentage greater than 10% of peeled skin are also considered losses during the harvest, because they cannot be marketed for fresh consumption.

Limitations on study/implications: Data were collected only from the harvest; exact dates of irrigation and fertilizer application are not available as the study was conducted with cooperating producers. This factor is crucial for the quality and yield of date palm cultivars.

Findings/conclusions: The age of the plant represents a significant difference in the yield per hectare due to the number of clusters it has; the more clusters it has, the higher the yield. The relative humidity directly affects the quality of the dates, and there are a more significant number of bulging fruits (with peeled skin). In this evaluation, we found that the rains during August and September 2023 significantly affected the losses during the date harvest in that season.

Effect of saline concentrations and humidity percentage on alfalfa va-rieties (Medicago sativa L.) from the Mexicali Valley, Mexico.

2024-11-11T17:52:48+00:00

Objective: The aim of this experiment was to identify alfalfa varieties resistant to salt and drought stress in Mexicali Valley Mexico.

Design/methodology/approach: Four alfalfa (M. sativa L.) varieties were used: Cuf-101 C, FD9, Pioneer and Cuf-101 P. Drought stress resistance was evaluated using four different percentages of commercial peat moss substrate (100%, 50%, 25%, and 15%), and saline stress resistance was evaluated by applying four concentrations of NaCl (0 mM, 50 mM, 100 mM, and 200 Mm.The variables evaluated in each treatment were: plant height, number of leaves and root length. The data obtained were subjected to an analysis of variance using the SAS statistical package version 9.0 with an α=0.5.

Results: Alfalfa variety Cuf-101 had a good adaptation to both stresses with an average height of 11.28 cm and an average number of leaves of 3.54. Seed germination of alfalfa varieties (M. sativa L.) subjected to salt stress were affected even at the lowest NaCl concentration.

Conclusions: The alfalfa variety with the highest germination percentage in all NaCl concentrations was Cuf-101 C with 91.17%.

Molecular identification of fungal isolates from different tissues samples of Blueberry (Vaccinum sp) in Baja California

2024-11-22T19:40:17+00:00

Objective: Molecular identification of fungal isolates presents in fruits and leaf samples of Vaccinium with pathogenic or agro-industrial potential

Design/methodology/approach: Plant material (fruits and leaves) was collected in blueberry commercial plantations of San Quintin, Baja California, México. The samples were placed in humid chambers for fungal growth and then in culture plates with Potato-Dextrose-Agar alone or with lactic acid for purification. The resulting fungal isolates were cultured in liquid media, the total DNA was extracted and quantified, afterwards the ITS region was amplified by PCR, the fragments were purified and sequenced. Finally, the resulting sequences were compared in the NCBI database with the BLAST algorithm, the phylogenetic reconstruction was performed with the MEGA (v.10.0) software.

Results: A total of 22 isolates from Vaccinium were obtained from leaves and fruits. These isolates showed high identity percentages (96-100 %) with Botrytis, Didymella, Phoma, Alternaria and Cladosporium genera. The fruit isolates were closely related with B. cinerea Group I, whereas the leaf samples grouped with other complexes such as the C. cladosporoides, A. muriae, Dydimella bervipilosa and Phoma.

Limitations on study/implications: The use of the ITS region provides only a partial characterization in some types of fungi, the use of other molecular markers are required to fully characterize some isolates.

Findings/conclusions: The molecular characterization of the fungal isolates showed that most of the genera were saprophytes with phytopathogenic members reported. The reported genera could have an impact in post-harvest due fruit spoilage or by the presence of cytotoxic compounds. The presence of fungal genera (Cladosporium) with reported potential antagonistic and growth promoting capabilities was identified.

Consumptive water use in pecan trees in the Hermosillo Coast

2024-11-11T17:54:39+00:00

Objective: To estimate the consumptive use of water for pecan trees (Carya illinoinensis).

Design/methodology/approach: In this study, the consumptive use of water for pecan trees was estimated by applying the water balance equation (Irrigation + rainfall-ETc=0).

Results: The results obtained from the 2020 to 2023 cycles show that an average irrigation depth of 1,365 mm should be irrigate per cycle, similar to the ETc estimated in situ by the Eddy Covariance Method.

Limitations on study/implications: Regional scope.

Findings/conclusions: The water balance is positive and shown a water surplus of 369 mm per cycle. This means that, considering only irrigation, savings of 147 mm per season could be achieved, representing an average of 1,470 m³ ha^-1 per agricultural cycle, without causing water stress for pecan trees.

Response to chemical and organic fertilization in date palm (Phoenix dactylifera L.) Mejhoul variety in Northwestern Mexico

2024-11-11T18:01:12+00:00

This research was conducted to determine the effect of chemical, organic, and combined fertilization on the fruit yield of the Mejhoul date palm variety in Northwestern of Mexico. The variables measured were polar diameter, equatorial diameter of the fruit, roundness index, number of clusters, number of leaves per palm, number of leaves per cluster, fruits with separated skin, dried fruits and commercial yield. The design used was complete randomized blocks with five replicates, where each palm tree was the experimental unit. The results indicate that chemical fertilization 262N-138P₂O₅-540K₂O alone or in combination with compost application (three or six tons per hectare) increases polar and equatorial diameter, promoting the oval growth of dates. Fruits with separated skin continue to occur regardless of the origin of the fertilizers. The number of fruits increases with chemical fertilization, but the total yield of dates remains consistent across the treatments evaluated. In conclusion, date palms respond favorably to the combination of chemical and organic fertilization, but date yields did not increase.

Seed Quality Assessment of the Blue Corn Hybrid Vampiro H10 (Zea mays L.) Through Its Parental Genotypes

2024-11-11T18:08:15+00:00

Objective: To monitor the physical and physiological quality of the trilinear corn hybrid Vampiro H10 seeds through its parental genotypes and to rank the evaluated characteristics according to their importance for germination and seedling development.

Design/methodology: Using a completely randomized design with four replications (100 seeds), in parental genotypes of the hybrid Vampiro H10 seeds, it was evaluated their physical (width, thickness, length, volume, relative density, and width/length and thickness/length ratios) and physiological characteristics (normal and abnormal seedlings, inert seeds, and dry weight and length of plumule, radicle, and total). Seed germination was estimated by the proportion of normal seedlings produced. The results underwent analysis of variance, comparison of means (Tukey's test, P ≤ 0.05), and principal components analysis.

Results: Each cross involved in the formation of Vampiro H10 made different contributions to the seed characteristics. In the single cross, the physical dimensions and dry matter of the seedling were increased, and in the trilinear cross, the formation of normal seedlings, radicle elongation and biomass were favored. This indicated that the hybridization sequence first affected the dimensions and then the physiological quality of the seed.

Limitations of the study: No limitations were presented for the present study.

Conclusions: An increase in volume, weight and length of seed was observed in the single cross and an increase in germination and seedling development in length and biomass was observed in the trilinear cross.

Nutritional potential value of Sesbania grandiflora (L.) Pers., La-blab purpureus (L.) Sweet, and Vigna radiata (L.) Wilczek in two sowing methods

2024-11-11T18:09:31+00:00

Objective: To evaluate the agronomic performance and nutritional potential of Sesbania grandiflora, Lablab purpureus, and Vigna radiata in two sowing methods.

Design/methodology/approach: The morphological and bromatological parameters of leaves and stems of S. grandiflora, L. purpureus, and V. radiata sown flat and in beds were determined. The forages of leaves and stems of the three species were classified according to their quality parameters. Data for morphological and bromatological parameters were analyzed with a completely randomized design with a 3x2 factorial arrangement and least squares means were compared with Tukey (p<0.05).

Results: Sesbania grandiflora in flat and bed sowing presented greater height, higher percentage of leaf dry matter, and percentage of stem dry matter. While V. radiata in flat sowing presented greater plant weight, leaf weight and stem weight. Sesbania grandiflora leaf forages in flat and bed sowing obtained a higher percentage of crude protein, while V. radiata in flat and bed sowing obtained a lower percentage of neutral detergent fiber. For stem forage, the three species in flat and bed sowing presented high percentage values of neutral detergent fiber and acid detergent fiber. The leaf forages in bed sowing were classified as excellent quality, as were the leaf forages of S. grandiflora and V. radiata in flat sowing, which also had excellent quality.

Findings/conclusions: The forage of S. grandiflora leaves in flat and bed sowing was of excellent quality, related to its higher percentage of dry matter and crude protein and its lower percentage of neutral detergent fiber and acid detergent fiber.

Economic Viability of Organic Fertilization in Forage Oats (Avena sativa L.) in the Mexicali Valley

2024-11-11T18:10:32+00:00

Objective: To economically evaluate the use of chemical, organic and organic-mineral fertilizers in of forage oat production in the Mexicali Valley; and to determine the profitability of each fertilization type.

Design/methodology/approach: Three treatments were established, one chemically fertilized (T1), one with organic fertilization (T2), and one with organic-mineral fertilization (T3) with two replications under a completely randomized design. Cash flow, financial costs and economic costs were calculated.

Results: Fertilization costs accounted for between 37% and 52% of the cost structure. Treatments T2 and T3 did not cover production costs. Only treatment T1 treatment demonstrated the ability to cover both production and financial costs. None of the treatments covered economic costs.

Limitations on study/implications: It is suggested to replicate the economic viability analyses in consecutive productive cycles, as other studies have shown positive impacts on soil fertility.

Findings/conclusions: The organic and organic-mineral fertilization systems (T2 and T3) were not profitable in the short term. The chemical fertilization system (T1) demonstrated the ability to cover, in addition to production costs, the depreciation costs of fixed assets. However, none of the treatments showed the ability to compensate the risk of investing in the activity.

Effect of Vermicompost and Phyto-regulator on Zucchini Fruits (Cucurbita pepo L.) Grown in Shade Houses

2024-11-11T18:13:53+00:00

Objective: To assess the influence of vermicompost (LC) and phytoregulator (AMP) in the cultivation of zucchini, under shade house conditions.

Design/methodology/approach: A randomized block experimental design with eight treatments and six repetitions was used.

Results: The treatments did not affect fruit diameter and pH variables. The Jacobo+LC+AMP treatment induced fruit length, and all treatments where the phytoregulator was applied increased fruit weight and commercial yield. For fruit firmness and total soluble solids, the trend was not clear due to the effect of the treatments.

Findings/conclusions: The application of the phytoregulator induced fruit weight and yield.

Tomato (Solanum lycopersicum L.) yield and quality depending on the osmotic potential and the number of stems

2024-11-11T18:18:00+00:00

Objective: To evaluate the biochemical components, physical characteristics (number of stems and fruit), and yield of Saladette tomato (Solanum lycopersicum L.), Var. Cid F1, grown under greenhouse conditions and its response to a constant increase (from 1 to 2.5 dS m^-1) of the osmotic potential of a nutrient solution, during three phenological stages (transplantation, 2nd cluster fruiting, and 6th cluster fruiting) of plants subjected to a single- and two-stem training system.

Design/Methodology/Approach: A sampling was carried out in the 5th cluster to determine the physical characteristics (firmness, size, number, color) and biochemical components (total soluble solids, titratable acidity, vitamin C, lycopene, pH, electrical conductivity, and ripening index) of the fruits. The experiment was established in 2018, under a greenhouse hydroponic system at Colegio de Postgraduados. The experiment was set as randomized complete block design with four replicates.

Results: The increase of osmotic potential and pruning had a positive effect on yield and number of fruits without affecting the biochemical components. Regarding the physical characteristics, T1 had 76% large fruits, 19% medium-sized fruits, 4% small fruits, and 1% tiny fruits.

Study Limitations/Implications: This methodology should be evaluated to other tomato varieties using different substrate mixtures and rates of chemical and organic fertilizers to evaluate water response and crop yield.

Findings/Conclusions: Increasing the osmotic potential of the nutrient solution, during phenological stages of maximum water and nutrient demand and the removal of old leaves had a positive response by increasing fruit number, size, and yield.

Bioprospecting of rhizobacteria with antagonistic activity against Fusarium spp., a parasite of cucumber (Cucumis sativus)

2024-11-11T18:27:46+00:00

Objective: To identify bacteria of genus Bacillus which, isolated from the tomato and cucumber rhizosphere, have an antagonistic effect against Fusarium spp. isolated from cucumber plants in Culiacan, Sinaloa.

Design/Methodology/Approach: Both the in vitro and in vivo antagonisms of rhizobacterial isolates against Fusarium spp. on cucumber plants were evaluated. Bacteria with the highest antagonistic effect were identified based on their morphological and molecular characteristics.

Results: Isolates FA15 and FA16 showed the highest in vitro biological efficacy against Fusarium spp., with 50.0% and 61.36% inhibition of mycelial growth, respectively. Rhizobacterium FA15 achieved the highest biological efficacy (88.89%) against Fusarium spp. in cucumber plants, while rhizobacterium FA16 recorded a 59.27% efficacy. The morphological and molecular characterization of isolates FA15 and FA16 confirmed a 100% molecular identity between FA15 and Bacillus velezensis and FA16 and B. subtilis.

Study Limitations/Implications: The rhizobacteria identified in this study inhibited the mycelial growth of the phytoparasite. Therefore, further studies about these rhizobacteria should be carried out to determine the potential antibiosis that may cause the inhibitory effect.

Findings/Conclusions: During the search for native beneficial rhizobacteria, two bacteria that exercise a biologically-effective control over Fusarium spp were identified in Culiacan: Bacillus velezensis and B. subtilis. This finding offers an opportunity in the agricultural biotechnology field to study beneficial native species that could provide an alternative to the use of chemicals.

Glyphosate-, carbofuran-, and chlorpyrifos-tolerant Priestia aryabhattai, isolated from agricultural soils

2024-11-11T18:54:42+00:00

Objective: To isolate and carry out a molecular characterization of microorganisms potentially tolerant to high concentrations of different pesticides (glyphosate, carbofuran, and chlorpyrifos).

Design/Methodology/Approach: Based on the isolate project SIP20170193, only the strain GVE 5 was chosen for the experiment, as a result of its morphological and growth characteristics. The tolerance capacity (TC) of GVE 5 to three different pesticides (glyphosate, carbofuran, and chlorpyrifos) was evaluated in two different media (LB and M9). The only carbon source was 200 mg/L of each pesticide. GVE 5 was identified through the Polymerase Chain Reaction (PCR) molecular techniques and amplified by the 16S rRNA marker.

Results: Based on the TC analysis, the GVE 5 strain of Priestia aryabhattai recorded a growth with 200 mg L^-1 of glyphosate, carbofuran, and chlorpyrifos in LB medium and M9 minimal medium.

Study Limitations/Implications: There were no limitations or implications for this study.

Findings/Conclusions: Priestia aryabhattai is tolerant to 200 mg L^-1 of glyphosate, carbofuran, and chlorpyrifos. These results open new lines of research regarding the bioremediation of soils polluted by these agrochemicals. Priestia aryabhattai should be subjected to further evaluations as a plant growth promoter.

Infectivity and effectiveness of an arbuscular mycorrhizal fungi native inoculum on the growth and absorption of macroelements in maize (Zea mays L.) plants

2024-11-11T19:05:47+00:00

Objective: To evaluate the impact of an arbuscular mycorrhizal fungi (AMF) native inoculum on the growth and absorption of macroelements in maize (Zea mays) under seedbed conditions.

Design/Methodology/Approach: The experiment consisted of a completely randomized experimental design with four treatments (three inocula of arbuscular mycorrhizal fungi and an uninoculated control) and 30 repetitions, resulting in 120 experimental units. Two consortia of commercial AMF were used: AMF1, AMF2 and, one native AMF3 treatment. The experiment included a control (T) without inoculation. The variables evaluated were: total dry weight and mycorrhizal colonization in plants and nutritional content of nitrogen (N), phosphorus (P), and potassium (K) in plant tissue.

Results: The application of the native inoculum (AMF3) had a significantly greater impact on total dry weight, as well as on P and K content in plant tissue, than the rest of the treatments (particularly the control). AMF3 showed 18% more mycorrhizal colonization than the rest of the treatments.

Study Limitations/Implications: The experiment was carried out under seedbed conditions and did not include the production stage; therefore, the impact of the treatments on maize production is unknown.

Findings/Conclusions: Maize (Zea mays) plants had a positive response to inoculation with arbuscular mycorrhiza-forming fungi. The bio-technological potential of AMF3 (Claroideoglomus claroideum), a mycorrhizal consortium native to the rhizosphere, can be used to reinforce the development of maize plants, increasing the absorption of macroelements and inducing greater growth and root development.

Frequency of fungi associated with strawberry dry wilt and in vitro antagonistic impact of Trichoderma harzianum and Bacillus subtilis

2024-11-11T19:07:02+00:00

Objective: To determine the frequency of fungi associated with strawberry dry wilt and to evaluate the antagonistic impact of Trichoderma harzianum and Bacillus subtilis.

Design/Methodology/Approach: Three sampling sessions were conducted in strawberry plantations in the Zamora Valley to isolate and identify fungi associated with strawberry dry wilt and to determine their frequency. In vitro antagonism tests were performed between Trichoderma harzianum, Bacillus subtilis, and fungi isolated from strawberry plants showing wilt symptoms. Additionally, the percentages of mycelial growth inhibition were determined.

Results: Six fungi were isolated from diseased plants showing wilt symptoms. The most frequent fungi were: Neopestalotiopsis sp. (54.7%), Fusarium oxysporum (50.6%), and Rhizoctonia solani (40.5%). Trichoderma harzianum inhibited >90% of the radial growth of Rhizoctonia solani mycelia, of Cylindrocarpon sp., >80% of Fusarium solani, and F. oxysporum mycelia, and 77.7% of Neopestalotiopsis sp. mycelia. Bacillus subtilis recorded the highest antagonism against Rhizoctonia solani (57%).

Study Limitations/Implications: This research faced no limitations.

Findings/Conclusions: In vitro tests determined that Trichoderma harzianum can inhibit the mycelial growth of fungi associated with strawberry dry wilt. Bacillus subtilis had a lower capacity to inhibit the mycelial growth of the confronted fungi than Trichoderma harzianum; however, it was the most effective bacterium against Rhizoctonia solani.

Physical, chemical, and microbiological parameters of soil under different tillage types.

2024-11-11T19:09:06+00:00

Objective: To determine the effect on the chemical, physical and biological properties of soils under minimum tillage and conservation tillage in different locations in Sinaloa.

Design/methodology/approach: The treatments were evaluated using a completely randomized experimental design, with a total of eight treatments or sampling sites, where five samples per site were collected at a depth of 30 cm. A total of 40 samples were obtained, which were preserved in a thermal box and were transferred to the microbiology laboratory of the Faculty of Agronomy (UAS). The variables evaluated included the quantification of bacteria on plates, where the number of total bacterial colonies (TB), phosphate solubilizing bacteria (PSB), nitrogen-fixing bacteria (NF) and indole-promoting bacteria (IPB) were determined. In addition, organic matter, electrical conductivity and pH were determined.

Results: Soils under minimum tillage modality significantly promoted higher percentage of organic matter, a greater number of bacterial colonies and higher electrical conductivity compared to soils with conventional tillage modality.

Limitations on study/implications:

Findings/conclusions: Agricultural tillage intervenes in the physical, chemical and microbiological properties of soils, as the sampling sites where minimum tillage is practiced show a higher concentration of organic matter and therefore leads to greater microbiology and electrical conductivity in those evaluated soils.

Potentially mineralizable nitrogen: Estimation of the labile and stabilized pools under woodland and cultivated soils in Mexico

2024-11-22T19:47:14+00:00

Objective: The aim of this work was to evaluate nitrogen pool and its variation due to land uses in different soil orders.

Design/methodology/approach: Alfisols, Entisols and Inceptisols under different uses (woodland and cultivated soils) were incubated for 20 weeks under controlled temperature and humidity. The mineralizable N (NO₃^--N and NH₄⁺-N) was obtained and the potentially mineralizable nitrogen (N₀) was estimated by the method of iterative adjustment. Nitrogen from 0 to 5 weeks was considered as labile nitrogen, and from 5 to 20 weeks was the stabilized nitrogen. The labile nitrogen was described by a potential model, while the stabilized nitrogen was described by a logistic model. The labile nitrogen and stabilized nitrogen pools were estimated after obtaining the first derivate and solving the integral of the potentially mineralizable nitrogen equation.

Results: The greatest estimated amounts of labile and stabilized nitrogen were detected in an Alfisol under woodland use, and the minimum values were obtained in an Entisol under agricultural use. Similar results were obtained for the estimated amount of labile and stabilized nitrogen pool.

Limitations on study/implications: It is important to measure the labile and stabilized fraction of nitrogen, which requires long-term incubations to obtain models of soil N pools, so other methods realiable and faster need to be considered.

Findings/conclusions: The potentially mineralizable nitrogen was positively related to the different fractions of labile and stabilized nitrogen under the different land uses.

Chemical Properties of a Water-Eroded Soil Amended with Mixtures of Dunaliella salina and Organic Fertilizers

2024-11-11T19:33:44+00:00

Objective: Evaluar el efecto de la incorporación de Dunaliella salina mezclada con fertilizantes orgánicos en un suelo erosionado hídricamente a través de algunas propiedades químicas, como una alternativa para mitigar los efectos causados por la erosión.

Design/methodology/approach: Se tomaron muestras de suelo erosionado, y este fue adicionando con dos dosis de fertilizante equino (C) y bovino (V) mezclado con D. salina, teniendo los tratamientos: C (control 0.2% de D. salina), Va (70,000 kg ha-1 y 0.2% de D. salina), Vb (35,000 kg ha^-1 de abono y 0.2% de D. salina), Ca (70,000 kg ha^-1 y 0.2% de D. salina), Cb (35,000 kg/ha^-1 y 0.2% de D. salina). Después de la aplicación de cada tratamiento, se analizó materia orgánica, conductividad eléctrica, pH y mineralización de N a los 15, 30 y 45 días.

Results: Los tratamientos con mayor porcentaje de materia orgánica y conductividad eléctrica en todos los tiempos fueron Ca y Va. En los tratamientos Va y Ca, el pH se mantuvo neutro y con los valores más altos respecto a los demás tratamientos a los 15, 30 y 45 días después su incorporación.

Findings/conclusions: El tratamiento Va tuvo el mayor contenido de N desde los 15 días hasta los 45 días. Los resultados sugieren que la aplicación de abono orgánico con D. salina puede compensar los déficits en las propiedades químicas causados por la erosión hídrica.

Effect of Laser Pre-Treatment on Peanut Seeds on Resveratrol Con-tent and Fatty Acid Profile in Field-Harvested Seeds

2024-11-11T19:34:45+00:00

Objective: To evaluate the effects of laser radiation on peanut seeds as a pretreatment on the resveratrol content and fatty acid profile in the harvested seeds.

Design/methodology/approach: The experiment was established under field conditions located in the municipality of Nicolás Bravo, Chiapa de Corzo, Chiapas. The seeds were irradiated with a red laser with a wavelength of 636 nm and an intensity of 120 mW. The exposure time of the seeds to the laser was 15 min and non-irradiated seeds were used as a control.

Results: Laser radiation on seeds increased the resveratrol content in the harvested peanut seeds compared to control seeds, and changes were also observed in some fatty acids in peanut oil such as butyric acid, stearic acid and cis 11,14,17 eicosatrienoic acid. Findings/conclusions: laser irradiation applied to seeds is a low-cost biotechnological alternative that allows generating positive changes in the quality of grains from seeds harvested under field conditions.

Morphological, Molecular, and Pathogenic Characterization of Rhizoctonia solani Isolates Associated with Bean Drying in Northern Sinaloa, Mexico.

2024-11-11T21:33:56+00:00

Objective: The objective of this study was to characterize, using morphology, DNA sequence analysis, and pathogenicity, R. solani isolates associated with bean plants with root rot symptoms in commercial plots in northern Sinaloa.

Design/methodology/approach: During the 2020-2021 cycle, diseased plants infected by Rhizoctonia were collected in the municipalities of Ahome, El Fuerte, and Guasave. Pure fungal isolates were obtained in specific media; which were morphologically characterized in PDA medium and preserved. Subsequently, the pathogenicity of the isolates was evaluated and they were molecularly identified. Genomic DNA was extracted from the isolates, part of the RPB2 gene was amplified by PCR, and the amplified products were sequenced.

Results: Phylogenetic analysis with RPB2 sequence data confirmed the identification of 63 isolates as R. solani and allowed them to be assigned to the anastomosis group (AG): AG-4. Of the total isolates analyzed, 86% correspond to the AG-4 HGI anastomosis subgroup and 14% to the AG-4 HGIII subgroup. In pathogenicity, the percentage of germination and severity of the isolates were evaluated, showing different levels of pathogenicity.

Limitations of the study/implications: None.

Findings/conclusions: Rhizoctonia solani AG-4 anastomosis subgroups HGI and HGIII are associated with bean drying in northern Sinaloa. Therefore, this study will serve as a basis for other studies that generate control strategies for this pathogen.

Extraction of nitrogen and distribution of dry matter in forage corn (Zea mays L.) in a clayey soil

2024-11-11T21:36:03+00:00

Objective: To analyze nitrogen extraction in forage maize (Zea mays L.) and its distribution in the plant's stems, leaves, ears, and husks under different fertilization rates, and to determine the total dry matter (DM) yield in the plant and in each of its organs.

Design/methodology/approach: Plots of forage maize were established to evaluate treatments with different nitrogen fertilization rates in a randomized complete block design with four replications in clay-textured soil.

Results: The behavior of nitrogen extraction in forage maize production on clay soil was observed. No significant differences were found among the treatments. The DM yield was very low, ranging from 13.72 to 16.52 t ha⁻¹. The percentage of DM distribution was higher in the ear and lower in the husks, and the same pattern was observed for N extraction. Findings/conclusions: The dry matter yield in forage maize was not significantly affected by the applied nitrogen rates, and the yield was very low. The percentage of dry matter in the ear did not reach the 45% that the crop should have. Palabras clave: N rates, yield, plant organs.