Ecosistemas y Recursos Agropecuarios is an international journal published every four months in December, April and August. It publishes original and previously unpublished Scientific Articles, Scientific Notes and Review Articles, from researchers of any national or international educational institution or research center, in an electronic and printed open access format. The journal’s aim is to create a space for discussion and dissemination of results and advances of original and unpublishe
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Molecular identification and in vitro antifungal activity of actinobacterial isolates against Colletotrichum gloeosporioides
The use of Streptomyces is an important strategy for the control of postharvest diseases caused by Colletotrichum. The objective of this study was to evaluate the in vitro antifungal activity of actinobacterial isolates against C. gloeosporioides and identify those with higher activity by sequencing the 16S rRNA gene. The experiments were performed using a completely randomized design with three replications for each isolate: BVEZ series (76 isolates) and serial BVEZMW (122 isolates). Molecular identification was performed by Sanger sequencing using the 16S rRNA gene. The results showed that 28 and 21% of the isolates exhibited antifungal activity against C. gloeosporioides for the BVEZ and BVEZMW series, respectively. Molecular identification revealed that the five outstanding isolates belong to the genus Streptomyces. The Streptomyces spp. in this study could be a source of antifungal secondary metabolites with potential for the control of anthracnose caused by C. gloeosporioides.
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Dynamic model for estimating biomass and carbon in forests of northern Mexico
Aboveground biomass is frequently used as an indicator of forest productivity and carbon storage capacity. The aim of this study was to develop a model for estimating biomass and carbon as a function of stand-level variables. We used data from permanent sample plots established in the forests of the ejido La Ciudad, Durango, where quadratic mean diameter, dominant height, volume, and basal area were measured. Seven growth functions were fitted for each explanatory variable, and their performance was evaluated using mean bias, root mean square error (RMSE, RMSE %), coefficient of determination (R2), and the Akaike Information Criterion (AIC). The model with the best statistical fit and biological behavior was then selected and expressed in dynamic form through the algebraic difference approach (ADA) to allow base-state–invariant projections. The Gompertz model that included basal area provided the best fit, yielding an R2 of 0.874 and a relative error of 15%. The resulting dynamic formulation enabled forward and backward projections of biomass based on changes in basal area and showed the ability to represent growth trajectories under different basal area levels. The results demonstrate the usefulness of the model as a tool for forest planning, evaluation of silvicultural scenarios, and carbon stock estimation for climate-mitigation purposes in natural forests.
Technology Transfer and Diffusion of NPK Fertilization in Maize: Trajectories and Networks
Nitrogen, Phosphorus, and Potassium (NPK) fertilization is a key determinant of maize yield, yet adoption is uneven across territories. This study analyzed the temporal adoption trajectory and the interpersonal diffusion of NPK fertilization in Mexico using a retrospective survey of 37 078 producers from 15 states. The year of adoption and the source actor from whom the innovation was learned were recorded. Based on Rogers’ diffusion of innovations theory, producers were classified into innovators, early adopters, early majority, late majority, and laggards. Adoption reached 52% and exhibited S-shaped trajectories with cross-state asynchronies. Innovation sources were reconfigured: Family predominated at the outset, institutional channels gained greater weight during the transition, and extension agents and input suppliers led in later phases. The findings support differentiated interventions by stage and territory. The approach integrates chronology, stages, and actors, and is replicable in extension.
Detection of antimicrobial resistance genes in Salmonella isolates in the Region Laguna, Mexico
The Region Laguna is known for its poultry farming. This activity carries zoonotic risks. One of these risks is Salmonella, the leading foodborne pathogen responsible for a significant proportion of deaths worldwide. In this study, the specific prevalence of Salmonella in broiler chicken feed, drinkers and chicken manure samples on farms was determined, as well as the presence of genes that confer resistance to antibiotics. A total of 240 samples were analyzed, of which 80 samples of them tested positive for Salmonella, and the only serotype identified was S. Thyphimurium. The most frequently observed genetic profile of antibiotic resistance, at 26.25%, was the tetra-resistant ACSSu. Only three of the isolates carried all six antibiotic resistance genes, so they can be considered mult-resistant. The results indicate that, in poultry environments in the Region Laguna, there are strains of Salmonella with patterns of multi- antibiotic resistance.
Genetic control and early selection of Pinus pseudostrobus var. apulcensis in Mixteca oaxaqueña
The Mixteca region of Oaxaca exhibits high rates of deforestation and soil erosion. Native pines have potential for establishment in this region, but early genotype selection is necessary for greater success. This study aimed to evaluate the genetic parameters of dendrometric traits and identify the best families of Pinus pseudostrobus var. apulcensis for reforestation and timber plantations. In a three-year-old progeny trial comprising 64 families, phenotypic and genetic variation, heritability, and genetic and phenotypic correlations of growth, stem quality, and survival traits were evaluated. Three selection strategies (E1, E2, and E3) were used to identify the best-performing families. Phenotypic variation ranged from 22.2 to 42.9% and was much higher for survival (115.8%). Additive genetic variation was moderate (6.69–12.25%). Individual heritability ranged from 0.06 to 0.26, while family-mean heritability ranged from 0.10 to 0.35. Genetic and phenotypic correlations among growth traits were positive and significant. Strategy E1 identified families with higher survival, E3 selected families with greater growth, and E2 balanced survival and growth; two families (Chi04 and Jal14) were selected by all three strategies. The existing variation and genetic control in Pinus pseudostrobus var. apulcensis are adequate for genetic improvement. The choice of selection strategy will depend on whether priority is given to survival under limiting environments or to the improvement of dendrometric traits for timber production.
Tolerance to salinity in irrigation water in vinca (Catharanthus roseus L.)
Salinity represents a challenge for farmers, especially those growing ornamental crops, because the esthetic appearance of the plants determines their commercial value. Vinca is a plant of ornamental interest but also for its high pharmaceutical value as it produces valuable compounds with medicinal properties. In the present study, the effect of salinity by NaCl in the nutrient solution on biomass accumulation and its effect on antioxidant capacity and nutrient status in two cultivars, Polka Dot and Valiant, of vinca was evaluated. Salinity from NaCl affected the growth and nutrient absorption of Polka Dot, making this cultivar more sensitive to salt stress. The Valiant cultivar demonstrated tolerance to salinity even at a concentration of 35 mmol of NaCl as its growth remained unaffected. Salinity caused a nutrient imbalance in Polka dot as the foliar concentration of Ca and K decreased. Polka dot, despite being more sensitive to salinity, produced a higher concentration of flavonoids and had greater antioxidant activity.
Polyphenol content in grains of maize landraces inoculated with arbuscular mycorrhizal fungi
Native Mexican maize contain a wide range of genetic diversity and valuable phenolic compounds such as anthocyanins and flavonoids. Cyanidin-3-glucoside (C3G) is the predominant anthocyanin, and together with flavonoids such as catechin, it contributes to grain pericarp pigmentation, enhances plant protection against oxidative stress, and provides antioxidant and nutraceutical benefits relevant to human health. Recent studies have proposed that symbiosis with arbuscular mycorrhizal fungi (AMF) can stimulate the biosynthesis of antioxidant metabolites through modifications in plant molecular signaling pathways. The objective of this study was to evaluate the effect of AMF inoculation on the content of polyphenols (C3G and catechin) in native maize grains (Yellow, Red and Black) under field conditions. A two-factor experimental design was established, with treatment factors “variety” and “mycorrhizal inoculum”.The percentage of mycorrhizal colonization was measured at V7 vegetative stage and VT transition stage. Concentrations of C3G and catechin in grains were quantified through methanolic extractions and spectrophotometric analysis at 535 nm and 450 nm, respectively. Inoculated treatments showed higher rates of mycorrhizal colonization (Yellow: 87.95%, Black: 73.82%, Red: 72.02%). Higher concentrations of C3G were observed in Black (51.26 mg kg⁻¹) and Yellow maize (12.68 mg kg⁻¹), while a 9.65% increase in catechin was detected exclusively in inoculated Black maize. The results obtained show that AMF inoculation can be a useful tool for increasing the nutraceutical compounds contents, such as polyphenols, in grains of native maize varieties.
Predictive modeling of reference evapotranspiration under shade net conditions using genetic programming
Reference evapotranspiration (ETo) is a key parameter for efficient irrigation management, especially in protected agriculture systems located in arid and semi-arid climates. This study aimed to develop a predictive ETo model within a shade net greenhouse using evolutionary computing techniques, specifically genetic programming (GP). For model development, climatic data were collected at one-minute intervals, allowing for high-resolution capture of the specific microclimatic conditions within the protected environment. The model was trained using ETo values calculated with the FAO-recommended Penman–Monteith method (FAO56-PM), considered the international standard for reference evapotranspiration estimation. The resulting model exhibited outstanding performance, achieving a root mean square error (RMSE) of 0.217 and a coefficient of determination (R2) of 0.99, indicating high predictive accuracy. When compared to widely used empirical models such as Hargreaves–Samani (RMSE = 4.82, R2 = –0.98) and Priestley–Taylor (RMSE = 1.00, R2 = 0.913), the proposed model significantly outperformed both traditional approaches. These results highlight the potential of genetic programming as an effective tool for developing robust predictive models tailored to specific conditions, such as those found in protected agricultural systems under arid and semi-arid climates.
Evaluation of predictive models of carcass tissue composition in Black Belly sheep
This study aimed to evaluate the adequacy of predictive models of carcass tissue composition in Black Belly sheep using an independent database of sixteen male sheep aged six months and weighing 31.99±2.38 kg. The animals were slaughtered, and the carcasses were refrigerated at 1°C for a 24-hour period. The carcass was then split along the dorsal midline and 9–11 rib section was removed from the left half. The remainder of the left half of the carcass was dissected into muscle (TCM), fat (TFC) and bone (TCB), and the weight of each component was adjusted to account for the total carcass weight. Regression analysis showed that the intercept (β₀) differed from 0 in all models (P > 0.05). However, the slope (β1) did not differ from 1 (P > 0.05). All models showed moderate to high precision (0.59 ≤ r² ≤ 0.82). The TMC and TCB models were highly accurate (bias correction factor: 0.94 ≤ Cb ≤ 0.99) and moderately to highly reproducible (0.76 ≤ CCC ≤ 0.90). In contrast, the TCF model had low Cb and CCC values. These results suggest that the TCM and TCB models could be used to predict muscle and bone content in Black Belly sheep with moderate precision and very high accuracy.
Peanut shells (Arachis hypogaea) as a substrate for habanero pepper producction
Peanut shell (Arachis hypogaea L.) is an abundant agroindustrial byproduct in various regions of Mexico, which, given its porosity and low specific weight, its use as a substrate is suggested. The objective of this work was to evaluate the effect of the particle size of the peanut shell and its combination with peat, on the development and production of the habanero pepper crop. The treatments studied consisted of particles smaller than 3 mm, larger than 3 mm, a mixture of particles larger than 3 mm with Peat moss in a 1:1 (v/v) proportion, as well as a combination of Peat moss and vermiculite in a 1:1 (v/v) proportion as a control. The same ones whose physical and chemical characteristics were determined, were placed in containers with a capacity of five liters and established in a greenhouse, under a completely random design, to transplant and let habanero pepper plants grow, to which the height and diameter of the stem and yield and quality of the fruit were measured. The results obtained show that particles smaller than 3 mm or, failing that, larger than 3 mm mixed with Peat moss, with physical characteristics of 77.69-81.68% total porosity (Pt), 32.36-36.01% aeration porosity (Pai), 42.11-49.32% moisture retention porosity (Prh), 0.09-0.15 g cm-3 of apparent density (Da), 5.42-5.45 pH and 0.96-1.39 dS m-1 electrical conductivity (CE), present values in plant development, yield and fruit quality similar to the control, confirming its potential as a substrate.
Effect of fortified milk on body weight and immunological status in goat kids
The objective of this study was to evaluate the effect of treatment with the commercial product Super Cria Goats Milk 65, from birth to weaning, on weight gain and hematological parameters in goat kids. Two groups were compared: Control Group (CG; 16 kids: 10 males, 6 females) and Artificial Lactation Group (ALG; 22 kids: 14 males, 8 females). During the experimental period, 4 kids from the ALG showed mechanical diarrhea. From day 20, CG kids (9.9 ± 0.19 kg; 184 ± 0.45 g d-1) showed significantly higher body weights and daily gain than ALG (7.65 ± 0.20 kg; 111 ± 0.24 g -1d) (p < 0.05). Likewise, CG kids had higher serum immunoglobulin concentrations, which is consistent with hematological results that showed elevated leukocyte and erythrocyte counts (p < 0.05). In contrast, platelets were higher in ALG kids (p < 0.05). Despite these differences, no mortality was observed in either group. These findings suggest that fortified milk may be a suitable alternative for use in different goat production systems under specific conditions and for: commercial milk, triplet births, mastitis, calf rejection, orphaned offspring, or disease prevention. Although naturally raised kids showed better growth and immune profile, ALG kids reached an acceptable weight (8.37 ± 0.12 kg) by market standards, compared to CG kids (11.5 ± 0.24 kg) at weaning. These results contribute to a paradigm shift for producers in the region regarding the use of artificial lactation.
Characterization of cattle ranches and their relationship with Scarabaeinae diversity in Frailescana
Livestock farming is a crucial economic activity, nevertheless, can exert environmental pressures such as the replacement of native vegetation, deforestation, and the creation of extensive grazing areas, leading to a decline in biodiversity and the loss of key ecological functions, such as those performed by dung beetles (Scarabaeinae). The aim of this study was to characterize livestock production units and determine how the size of the livestock production system affects dung beetle diversity. To this end, semi-structured interviews were conducted with 41 livestock farmers in the La Frailescana Natural Resource Protection Area, followed by stratified sampling based on ranch size for eight of them, using 30 baited pitfall traps per ranch (baited with bovine dung) for 48 hours. The data were analyzed using analysis of variance, cluster analysis, and diversity indices. The results revealed the existence of three groups of livestock farmers with significant differences in the number of cattle, the area of land used for livestock, and the number of animals sold per year. The species richness and abundance analysis showed a very similar composition of Scarabaeinae species between ranches classified as small and medium-sized, compared to large ones. It was concluded that beetle diversity was favored in landscapes with a mosaic structure integrating tree cover, grasslands, and live fences. It is suggested that establishing a production system that integrates trees (silvopastoral systems) may be beneficial for the conservation of soil fauna.
Response of cucurbits to parasitism by Meloidogyne incognita
In southeastern Mexico, the sedentary endoparasitic nematode Meloidogyne incognita parasitizes cucurbits, inducing varying degrees of virulence. The objective was to evaluate the response of regional cucurbits to M. incognita parasitism. Seedlings of Lagenaria siceraria, Cucurbita moschata, C. argyrosperma, C. pepo, Cucumis melo, C. sativus, and Citrullus lanatus variety "Cal sweet" were transplanted into pots and inoculated with 5 000 larval eggs of M. incognita. After 53 days inoculation, the galling index (GI), nematode reproduction, and agronomic variables were estimated. L. siceraria showed a lower GI (1-10%), with 10 and 267 females and eggs per gram of root, respectively. The largest stem diameter (5.47 and 5.15 mm) was recorded in L. siceraria and C. moschata, and the longest guide length in L. siceraria, C. melo, and C. moschata (102.50, 93.25, and 92.50 cm). L. siceraria shows potential as a rootstock tolerant to M. incognita.
Production and nutritional quality of Tithonia diversifolia (Hemsl.) A. Gray
To estimate the nutritive value, describe the growth and development of Tithonia diversifolia (Hemsl.) A. Gray, 29 plants were defoliated at intervals of 30, 60, 90 and 120 days, proximate analysis of dry matter and Van Soest analysis for fiber were performed. Analysis of variance and covariance, multiple comparison of means by least squares adjustment and regression models were applied; the maximum biomass accumulation achieved was estimated at 98 days after the emergence of the first leaves. Defoliation positively influenced all variables and an estimate of 136,375 t ha-1 of green matter was estimated at 150 days. The defoliation effect increased biomass and the stems represented the greatest weight. The maximum PC 19.6% and ELN 37% are shown at 30 days and for ADF and NDF the highest percentage at 60 days.
Seed weight and pregerminative treatments in the in vitro germination of Echinocactus platyacanthus and Echinocactus horizonthalonius
Echinocactus platyacanthus and Echinocactus horizonthalonius are in constant risk due to the deterioration of its natural habitat. The objective was to compare seed weight among E. platyacanthus and E. horizonthalonius and what effect does it have with seeds´s morphometric variables. To determine if the interaction among pregerminative treatments and seed weight have an effect on the germination percentage and seedling size as well and produce a morphological description of the seedlings for 60 days. The seeds of E. platyacanthus and E. horizonthalonius were divided into three weight categories. The pregerminative treatments were control, soaking in water for 24 hours, 25% sulfuric acid, 30% hydrochloric acid and mechanical scarification. The seedlings obtained with mechanical scarification were photographed for morphological description for 60 days. Weight category 3 of E. horizonthalonius seeds showed the largest size with 3.06 ± 0.07 mm in length, 2.28 ± 0.07 mm in width, and an area of ​​5.09 ± 0.20 mm2. E. platyacanthus seeds of weight category 2 with 24-hour soaking water treatment, H2SO4, and mechanical scarification obtained 100% germination. The interaction of pregerminative treatments and seed weight indicate that the highest percentage of germination and seedling size is obtained with medium-sized seeds of E. platyacanthus and E. horizonthalonius. The mechanical scarification treatment promotes the hightest germination in E. horizonthalonius seeds. The seedlings of both species presented morphological differences in the first 60 days of growth.
Agronomic behavior and environmental variation of the Raton race in Tamaulipas, Mexico
Landrace maize can adapt to different climatic conditions due to their phenotypic and physiological variations. The objective of this study was to determine the correlation and stability of phenotypic variation and grain yield in early-maturing native corn populations grown under rainfed conditions using agronomic and environmental variables. The evaluations were carried out in the towns of Güémez, San Isidro, and El Paraíso in Tamaulipas, Mexico. Ten populations of native corn of the Ratón variety were established. Planting took place on February 29, July 4, and July 18 under a randomized complete block experimental design with three replicates each. Fifteen vegetative and phenological traits were evaluated, grain yield was calculated, and six environmental variables and 13 soil variables were assessed. A combined analysis of variance, an analysis of additive main effects and multiplicative interaction, and a partial least squares analysis were used. The 2Rat and 10Rat populations had higher grain yields with 2 441.05 kg ha⁻¹ and 2 394.37 kg ha⁻¹, while 3Rat had an average plant height of 221.99 cm at the three sites. In female flowering, the El Paraíso location had fewer days. The 2Rat population had a higher grain yield, but this was not associated with height and days to female flowering. 1Rat was taller and less productive,
Oil sunflower production with foliar application of zinc, iron and copper nanoparticles
Sunflower is one of the most important oilseeds worldwide and in Mexico only 7.5% of the volume consumed is produced, so it is necessary to look for alternatives to improve its production. The supply of nutrients such as nanoparticles could make assimilation in the plant more efficient and improve agricultural yield. The objective of the present study was to determine the effect of the joint foliar application of Zn+Fe+Cu nanoparticles at different doses and number of applications on sunflower production. On February 15, 2023, sunflower was sowing in soil and under irrigation conditions. The treatments consisted of the joint application of Zn+Fe+Cu nanoparticles each at doses of 10 and 20 mg kg-1 in two, four and six foliar applications, which generated six treatments plus the control without application. It was found that, except for the applications of nanoparticles at 10 mg kg-1 in two applications, with all other treatments, increased sunflower grain production, stem diameter, head area, head weight, harvest index and total biomass. The dose of 20 mg kg-1 was more effective in improving grain yield. The application of 20 mg kg-1 in four applications generated the highest yield (3.61 t ha-1) which represented a 35% increase compared to the control. Therefore, it is the most appropriate treatment to improve sunflower production.
Hydraulic retention time in the aquaponic cultivation of Swiss chard and Koi carp
Aquaponics is a sustainable alternative that integrates fish farming with hydroponic plant production, creating a system where plants utilize fish waste (N, P, and K), which is transformed by bacteria into assimilable nutrients. Hydraulic Retention Time (HRT) is a critical parameter that determines the time water remains in hydroponic beds, influencing nutrient availability. The objective was to evaluate the effect of HRT on the aquaponic cultivation of Swiss chard (Beta vulgaris var. Cicla). Additionally, koi carp (Cyprinus carpio var. koi) is a highly attractive species increasingly popular in ornamental ponds, which also require adequate physical and biological filtration for proper animal maintenance. Six HRTs (40, 60, 80, 100, 120, and 140 minutes) were randomly assigned. A total of 144 Swiss chard seedlings were cultivated in hydroponic beds for 40 days, while 350 juvenile koi carp were housed in the tank. The absolute growth rate and edible biomass of Swiss chard were calculated, along with water quality parameters. The results showed that the 40-minute HRT treatment achieved the highest productivity, with significant differences observed between 40–60 minutes and 120–140 minutes. Additionally, the need to supplement oxygen in the plant growth beds was identified. These findings highlight the critical role of HRT in optimizing productivity within aquaponic systems.
Extracts of Mexican mistletoe on the development and recovery of Phytophthora capsici
Phytophthora capsici affects a wide range of food crops; the use of natural products for its control is crucial to reducing the use of agrochemicals. The activity of four concentrations of extracts from the leaves and flowers of Mexican mistletoe (Psittacanthus calyculatus) on the development and recovery of the oomycete was evaluated during and after treatment. At the highest concentration (33.3%), the mistletoe leaf extracts inhibited pathogen growth by 50.6% and the flower extracts by 54.4%. They also caused decreased sporangium formation, alterations in colonial morphology, sparse mycelial development, hyphal modification and deformation, reduced pigment production in the culture medium, and loss of zoospore viability. However, the phytopathogen recovered its growth in 87% to 97% of cases, demonstrating the adaptability of P. capsici and the ability of the extracts to delay its development.
Biofertilizers in irrigated corn (Zea mays L.) production under two fertilization conditions
Given the high costs of chemical fertilizers, it is necessary to generate sustainable alternatives, such as biofertilizers. The objective was to evaluate corn (Zea mays L.) yield with the inoculation of Azospirillum brasilense (A), Bacillus subtilis (B) and Serindipita indica (S) and the different consortia in two doses of chemical fertilization, at 100% and 70% of the crop requirement. The trial was carried out under field conditions, in a factorial experiment, the microorganisms factor with eight levels and the chemical fertilization factor with two levels, with four replications. In the microorganisms factor, consortia with two microorganisms showed the greatest increase, followed by consortia with three microorganisms. Ear weight (BW) and grain weight (GW) were higher with the consortia of AB, SA and SAB, the average increases of the respective variables in relation to the control treatment were 16.3 and 51.8%. In the fertilization factor, with the 100% level, the PM and the weight of 200 grains were higher. There was interaction in green forage weight, dry forage weight with grain and stubble weight, with the consortia of SAB and fertilization at 100% the three variables were higher (p ≤ 0.05) than with SAB at 70%. With the consortia of AB or SA and 70% fertilization, the highest benefit/cost ratios (BCR) were obtained, the increases with respect to the control were 270 and 269%, respectively.
Pre-emergent bioherbicidal potential of microwave/ultrasound-extracted creosote bush and tarbush on buffalo gourd
Effective, safe weed control is crucial for sustainable food production. Bioherbicides derived from plant extracts present a promising alternative. Extracts from plants like creosote bush (Larrea tridentata) and tarbush (Flourensia cernua) contain allelopathic compounds that can disrupt weed germination and growth. The aim of this study was to evaluate the effect of L. tridentata and F. cernua extracts on pre-emergent control of buffalo gourd (Cucurbita foetidissima). Plant extracts were prepared using microwave and ultrasound technologies with "green" solvents and were applied at different doses [3 (low), 6 (medium), and 12 (high) L of extracts in 200 L per hectare] on C. foetidissima seeds, and their effect on germination, seedling growth, dry biomass, and mechanisms of action [on photosynthetic pigments (chlorophylls a, b, total, and carotenoids), total proteins, antioxidant enzymes (catalase and peroxidase), total phenolic compounds, antioxidant capacity, and oxidative stress (lipid peroxidation)] were evaluated. The phytochemicals like quercetin and (+)-gallocatechin in the bioherbicide extract were found. The high dose of the extract decreased germination rates and decreased seedling growth in C. foetidissima compared to the control. Although dry biomass showed no significant change, a trend toward reduction was observed in treated seedlings. Chlorophyll and carotenoid levels decreased in all treatments, while protein levels were unaffected. Low-dose treatments decreased catalase activity, and the high dose increased lipid peroxidation. This study demonstrates that allelopathic plant extracts effectively inhibit C. foetidissima seedling growth, with compound concentration and content critical to bioherbicide effectiveness
Lluvia de Abril Alexandra Soriano Melgar
Biofertilizing effect of coffee endophytic Trichoderma spp and Bacillus spp on corn cultivation
Trichoderma spp. and Bacillus spp., are used as biofertilizers in organic agriculture because they are growth promoters and inducers of the plant defense system. The objective of this work was to evaluate the biofertilizer effect of coffee endophytic Trichoderma and Bacillus species in maize (Zea mays) cultivation. Four species of the genus Trichoderma (T. longibrachiatum C1ca, T. asperellum C3moa, T. hamatum C10AOa, T. reesei C11M) and two species of Bacillus (B. amyloliquefaciens B49 and B. subtilis B17) were evaluated, where the treatments were combinations of fungi, bacteria and 50 and 100 % fertilization, having a total of 17 treatments and one control. The experiment was set up in completely randomized blocks with four replications. The variables that were measured were plant height, dry weight of roots, stems, leaves and yield. The data obtained were performed an analysis of variance (ANOVA) and a Tukey mean comparison test (P £0.05) using Minitab 19. As results, it was found that Trichoderma and Bacillus species promoted the growth of corn plants and increased the yield of the crop grain even in the treatments with 50 % fertilization, surpassing the absolute control and the treatment with 100 % fertilization. The application of Trichoderma and Bacillus increases corn yield and reduces the application of chemical fertilizer doses by up to 50 %.
CAERI 4, a new cocoa variety for production areas in Mexico
The “CAERI 4” cocoa clone originated from the cross between the Baalam x CATIE R6 cocoa clones, carried out at the INIFAP Rosario Izapa Experimental Field. It was evaluated in three environments (Tuxtla chico and Umoa, Chiapas and Teapa, Tabasco) and showed stability in most yield components, primarily the variables NST, IM, IS, yield tree-1 and yield per hectare. This indicates no interaction between the CAERI 4 clone and the environments; an important characteristic when releasing a new variety to producers. CAERI-4 is characterized by its tolerance to moniliasis (SE = 0.29 and SI = 044) and good yield (more than 1000 kg.ha-1). The CAERI 4 cacao clone was developed to facilitate the renewal of cacao plantations in Mexico, where moniliasis has reduced production, led to the abandonment of plots, consequently, changes in land use.
Productive potential of soybean crop under rainfed at high altitudes
Soybean (Glycine max (L.) Merrill) is the main source of protein in animal feed concentrates and various products for human consumption. However, its production has been focused in tropical climate zones and little research has been done in different environments. Therefore, the objective of this study was to evaluate the productive potential and grain quality of soybean crop in high altitude environments. To do this, under a randomized complete block design in five locations that covered an altitudinal gradient of 1900 to 2700 masl, the agronomic performance of eight varieties was evaluated under rainfed conditions. Days to flowering, biomass production and chemical quality of the grain were quantified. The average yield in the environment at 2040 m was 1.1 t ha-1, the oil and protein content was 18 and 31%, respectively. At an altitude of 2526 m, all varieties completed their cycle, with an average yield of 0.1 t ha-1, 15% oil and 31% crude protein. At an altitude of 2079 m, only the earliest variety completed its cycle; the other varieties delayed their flowering, causing this stage and the grain formation period to be affected by frosts. Biomass production also decreased with altitude. It is concluded that soybeans have productive potential up to altitudes of 2000 m, because at higher altitudes the yield decreases, although the protein content remains constant.
Characterization of the Water Buffalo Production System in Two Regions of Mexico’s Humid Tropics
Water buffalo production systems were characterized in two regions of Mexico’s humid tropics: Olmeca (Veracruz) and Grijalva (Tabasco). Semi-structured interviews were applied to producers. Descriptive analysis included frequency tables and percentages for qualitative variables and Student’s t-test for quantitative variables. In Veracruz, a meat-oriented system predominated, whereas in Tabasco the system was dual-purpose. At first, mating age was 21.2 ± 3.11 months in Veracruz and 18.8 ± 2.12 months in Tabasco. Milk production was higher in Veracruz (4.0 ± 1.00 L animal-1 day-1) than in Tabasco (3.5 ± 0.55 L animal-1 day-1), although the price was higher in Tabasco. Productive differences associated with regional management were evident.
Analysis of water stress in a bean crop using multispectral imaging and soil moisture sensors
The objective of this study was to analyze three index and two reflectance bands obtained with multispectral images captured by drones, to evaluate the degree of stress of a bean crop (Phaseolus vulgaris L.), under three levels of soil moisture tension and two positions of the drip irrigation tape (surface and buried). The results of the study showed that the Normalized Difference Water Index (NDWI) and the reflectance in the red-edge band (RE) had a better relationship with the moisture content resulting in high significant differences of more moisture content in treatment of buried drip irrigation tape and in the treatments of lower moisture tension. With the Normalized Difference Red Edge Index (NDRE), higher chlorophyll content (lower stress level) was detected in plants irrigated with the buried irrigation tape, for the treatments of lower water tension, a higher NDRE index represents a higher water content. With the Triangular Greenness Index (TGI), only was detected significant differences in the plant vigor (chlorophyll content of the leaves) in the water tensions of 30 kPa and 50 kPa based on the position of the tape or the difference between 20 kPa and 50 kPa of soil moisture tension. By analyzing the values of reflectance in the red band (R), a higher water stress was detected in the treatment of plants irrigated with the tape on the surface, but no differences in chlorophyll content of the leaves of plants were detected at tensions of 20 kPa and 50 kPa.
irrigation systems and agricultural technology
Effect of three sowing densities on sorghum bicolor development and performance in the tropics
The objective of the study was to determine the productive response of sorghum forage (Sorghum bicolor L. Moench) grown at different sowing densities in Loma Bonita, Oaxaca, Mexico. A complete randomized experimental design was used where treatments: chorrillo, 125 000, 178 571 and 250 000 plants ha-1 were tested under three repetitions, the experimental unit was 16 m2. The growth variables in study were: plant height, stem diameter, chlorophyll content in leaves, leaf length, leaf width and foliar area per plant. At harvest, yield components were taken, forage yield (t ha-1), plant weight, leaves and stems weight, panicle weight, number of spikelets and number of grains per spikelet. An analysis of variance was performed with GLM and mean comparisons were made in variables that were significant (Tukey, P ≤ 0.05). The results indicate that a chorrillo density generated a higher grain yield (4 420 kg ha-1) and forage (27 157 kg ha-1) above that obtained with the densities 125 000, 178 571 and 250 000 plants ha-1. The ALP, DTA, AFO, CLO, LHO and AHO were influenced by the sowing density up to 42 DDS, after 56 and up to 80 DDS there were no effect to the densities tested. There were positive correlations between ALP with APA, DTA, LPA and REG (ranging from r = 0.63** to r = 0.95**). Grain yield was correlated with AFO (r = 0.74**) and PCG (r = 0.61**). Forage performance was positively correlated with six studied traits.
Effect of bokashi fertilizer on the yield of Jaguar habanero pepper under conventional and organic production
The production of habanero pepper (Capsicum chinense Jacq.) in Mexico continues to be relevant. Bokashi is an organic fertilizer that can be used to fertilize the soil and increase plant growth and productivity. The objective was to evaluate different doses of the organic fertilizer bokashi in the cultivation of habanero peppers of the Jaguar variety under organic and chemical production systems. Four treatments of 0.00, 1.00, 2.00 and 3.00 t ha-1 of bokashi were established, the zero treatment was used as a control, and these treatments were applied under both conventional and organic production systems. The design used was a randomized complete block design with four replications; the agronomic management of the crop was according to the technological package generated at INIFAP. The data obtained from the agronomic variables of plant and fruit were analyzed with SAS 9.4 software. The management under chemical fertilization combined with 3.00 t ha-1 of bokashi organic fertilizer had the highest green fruit yield (27.22 t ha-1), while organic fertilization plus bokashi had the lowest yield 13.21 t ha-1. For mature fruit yield, chemical fertilization with the three doses of bokashi showed the highest yields (18.98 to 21.90 t ha-1). The best pepper yields at both fruit stages were with chemical management plus organic bokashi fertilizer, while organic management plus bokashi fertilizer recorded the lowest yields.
Performance and characteristics of tilapia (Oreochromis niloticus) meat feed with Moringa oleifera
The objective was to evaluate the effect of including moringa flour and skipjack fish waste in tilapia diets on productive performance and meat characteristics. Three diets were evaluated: Mo10 = 10% moringa, Mo20 = 20% moringa and DAco = Commercial food. Productive performance was recorded every week, carcass and fillet characteristics were analyzed when the fish were slaughtered. The study lasted seven weeks, the means were analyzed using the Tukey test (P < 0.05), for height correlations were analyzed for the data set. The productive variables had a better response (P < 0.05) with the moringa flour diets. There were differences (P < 0.05) between the morphometric variables of height in relation to the independent variable weight, being greater for Partial Length, Maximum Length and Total Length. The fishes that consumed the diets did not present differences (P > 0.05) in carcass yield. The physical characteristics of the fillet showed differences (P < 0.05). The temperature was higher with Mo20 at 45 minutes and lower at 24 hours post-mortem. The tilapia fillet with DAco tended towards red (a*), while with Mo10 and Mo20 the fillets tended towards a yellow color (b*). In drip loss, the fillet with Daco lost almost twice as much water as Mo20. It is concluded that the inclusion of 10 and 20% of moringa flour in the tilapia diet improved productive performance and did not affect the characteristics of the carcass and fillet.
Addition of nopal and maguey to corn stubble improves the voluntary consumption by goats
Corn stubble is a forage with low digestibility and protein content, but high in fiber, which makes its consumption very limited. The objective was to know if the addition of cactus or maguey to corn stubble increases voluntary consumption of stubble when used as a supplement for grazing goats. In the first trial, 10 goats crossed with Nubia of similar weight and age were offered corn stubble (S) added with four levels of nopal (0, 30, 50 and 70%, wet basis). The second trial, similar to the first, we replaced the nopal (N) by maguey (M). Both experiments lasted were performed simultaneously. In the third experiment, the best consumed diets in each of the two previous trials were tested (S30:N70 and S30:M70). In general, the consumption of supplement and stubble was better when the stubble was added with nopal or maguey. As the level of nopal increased supplement consumption increased (P < 0.0001) as well as the consumption of stubble (P < 0.0001). Similarly, the consumption of supplement and stubble were increased as maguey increased in the ration (P < 0.0001). The addition of nopal (trial 3) improved the consumption of supplement and stubble to a greater extent than when maguey was used (348.5 vs 271.9 g DM days-1). It is conclude that the addition of nopal or maguey to corn stubble is a viable way to increase voluntary consumption of stubble by goats. The acceptance of maguey as a supplement with corn stubble is lower than that of nopal.