Search

The use of phytonanoparticles in agriculture could decrease the use of fertilizers and therefore decrease soil contamination, due to their size being better assimilated in plants. It is important to mention that the nanofertilizer is slow-releasing and improves plant physiological properties and various nutritional parameters. The influence of soil and foliar applications of phytonanoparticles of ZnO with the Moringa oleifera extract under three concentrations (25, 50, and 100 ppm) was evaluated on the cherry tomato crop (Solanum lycopersicum L.). Synthesis of the phytonanoparticles was analyzed with ultraviolet-visible spectroscopy (UV-Vis) and infrared transmission spectroscopy with Fourier transform (FT-IR), as well as the analysis with the dynamic light scattering (DLS) technique. The morphometric parameters were evaluated before and after the application of the nanoparticles. The minerals’ content of fruits was done 95 days after planting. Results showed that soil application was better at a concentration of 25 ppm of phytonanoparticles since it allowed the greatest number of flowers and fruits on the plant; however, it was demonstrated that when performing a foliar application, the fruit showed the highest concentrations for the elements Mg, Ca, and Na at concentrations of 511, 4589, and 223 mg kg−1, respectively.

Las enfermedades causadas por Fusarium en Agave aumentan, lo cual significa importantes pérdidas económicas. Es necesario entonces buscar alternativas en la prevención y control de pató­genos para reducir el uso de fungicidas químicos, y así promo­ver un tipo de control de enfermedades que sea amigable con el ambiente. Los aceites y extractos de hojas de algunas plantas son eficientes en el control de plagas y enfermedades. Piper auritum (“hierba santa”) contiene aceites esenciales que cumplen funcio­nes ecológicas, como las de atraer polinizadores y causar efectos alelopáticos. Baccharis glutinosa (“jarilla”) también se usa en el tratamiento de diversas enfermedades infecciosas. Hay diferentes extractos de plantas que tienen una actividad biológica contra microorganismos que afectan cultivos importantes. El objetivo de esta investigación fue evaluar la actividad antimicrobiana del aceite esencial y extractos de dos plantas con uso tradicional en el estado de Chiapas sobre los hongos fitopatógenos (Fusarium spp.) de Agave spp. Los extractos de P. auritum y B. glutinosa se probaron contra los hongos fitopatógenos, como parte de un di­seño experimental completamente aleatorizado. Un ANOVA se realizó con seis tratamientos y tres repeticiones por tratamiento, utilizados en tres especies de Fusarium. El aceite esencial extraí­do de las hojas de Piper auritum tuvo el mayor efecto inhibi­dor significativo (96 h) sobre Fusarium oxysporum f. sp. comiteca (75.32%), Fusarium oxysporum f. sp. tequilana (86.57%) y Fu­sarium solani f. sp. comiteca (63.36%). Por lo tanto, P. auritum mostró un claro efecto fungistático.

Different types of nanoparticles (NPs) are increasingly used in multiple sectors such as industry, medicine and agriculture. This application has increased the possibility of NPs accumulating and c...

El chile xcat´ik (Capsicum annuum L.) es el segundo más consumido en la península de Yucatán, después del habanero. Los biofertilizantes microbianos son una opción factible de integrarse a los sistemas de producción para disminuir el uso de fertilizantes químicos. El objetivo del trabajo se basó en la evaluación del efecto de la aplicación de Bacillus subtilis, Trichoderma harzanium y un consorcio microbiano en las características agronómicas de la planta y la calidad del fruto del chile xcat´ik. El experimento se realizó en condiciones de invernadero, a través de un diseño experimental de bloques completos al azar con cuatro repeticiones. De acuerdo a los resultados se encontró que la aplicación de B. subtilis incrementó significativamente la altura de plantas respecto al testigo, así mismo la aplicación de B. subtilis y T. harzanium incrementó el volumen de raíz. Se observó que existen diferencias estadísticas en los contenidos de lípidos y proteínas en el fruto de plantas biofertilizadas con T. harzanium, y que en los frutos de plantas tratadas particularmente con B. subtilis y T. harzanium se acumulan mayores cantidades de fósforo.

Yam bean (Pachyrhizus erosus (L.) Urb.) tuber has a low carbohydrate content and contains several aminoacids, but contains few active compounds, such as vitamins and antioxidants. Anthocyanins are antioxidants found in Rubus fructicosus L. The osmotic drying is a technique that can be used to impregnate antioxidants in a matrix, so the objective of this study was to impregnate yam bean tuber slices with anthocyanin. The effect of temperature (40, 50 and 60oC), sucrose content (40, 50 and 60oBrix) and vacuum pulse (0, 300 and 600 mbar) on water loss (WL), solid gain (SG), color changes (ΔΕ) and anthocyanin concentration (ΔA) during osmotic drying of yam bean slices was determined. Polynomial equations were used to determine changes in WL, SG, ΔΕ and ΔA of yam bean slices after 6 h of osmotic drying. An osmotic solution at 60oC with a SC of 40oBrix, applying a vacuum pulse of 12 mbar maximized anthocyanin impregnation (6.67 mg anthocyanin per g initial dry matter) in tuber slices. The Page equation predicted optimum WL, SG and ΔA of yam bean tuber slices during osmotic drying. No relation was found between temperature, sucrose content and vacuum pulse with K and n parameters in the Page equation.

The carrot is considered a model system in plant cell culture. Spray drying represents a widely used technology to preserve microorganisms, such as bacteria and yeasts. In germplasm conservation, the most used methods are freeze drying and cryopreservation. Therefore, the aim of this work was to evaluate the effect of spray drying on the viability and totipotency of somatic carrot cells. Leaf, root and stem explants were evaluated to induce callus with 2 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Calli obtained from the stem were cultivated in a liquid medium with 1 mg/L of 2,4-D. Cell suspensions were spray dried with maltodextrin-gum Arabic and maltodextrin-xanthan gum mixtures, two outlet air temperatures (50 and 60 °C) and 120 °C inlet air temperature. Results showed that carrot cells were viable after spray drying, and this viability remained for six months at 8 °C. The totipotency of the microencapsulated cells was proven. Cells that were not spray dried regenerated 24.6 plantlets, while the spray dried cells regenerated 19 plantlets for each gram of rehydrated powder. Thus, spray drying allowed researchers to obtain viable and totipotent cells. This work is the first manuscript that reported the spray drying of plant somatic cells.

Moringa oleifera is a highly versatile plant with potential use in the agro-food and biochemical industry. The goals of this study were to evaluate the effect of chemical fertilization and vermicompost on plant growth, and to analyze the metabolomic profile of M. oleifera crops cultivated over agricultural and native soils. The extracts were obtained from 90-day-old leaves via extraction with a hydroalcoholic mixture. Multivariate data analyses, such as principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA), were used to differentiate the distribution of leaf metabolites according to the soils or types of fertilizers used for the cultivation of Moringa oleifera. The results indicated that there was no significant effect on parameters such as plant height, root length and dry weight of leaves (p &lt, 0.05). UPLC-ESI-MS/MS analysis of leaf extracts revealed a wide range of flavonoids, alkaloids and organic acids. The results of PCA and PLS-DA confirmed that the type of fertilizer had an effect on the metabolomic profile of M. oleifera leaves. The application of vermicompost induced changes in the metabolomic profile, but not in the morphometric variables of Moringa oleifera. These results are important for metabolite production via organic cultures and over different soil types in the industrialization of Moringa.

This work was conducted with the objective to evaluate the effect of vermicompost application on chemical characteristics, energetic parameters and amino acids prof ile of hybrid race corn grain cultivated under open-f ield and rained conditions. The experiment was accomplished under a randomized complete design with three repetitions. Three treatments were evaluated: 1) Maize after inoculation with a commercial mycorrhizal arbuscular fungi mixture (Tec Myc 60®) plus vermicompost (V+M); vermicompost (V) and chemical fertilization (CF). Starch content in grain was 1.9% higher in V+M treatment in comparison with chemical, whereas crude protein, ether extract, crude f iber, acid detergent f iber, neutral detergent f iber, total phosphorous and phytic phosphorous were not different between treatments. Energetic parameters were not different between three treatments. 17 amino acids were evaluated of wich only tryptophan, leucine, valine, histidine and aspartic acid were higher in CF and V treatments in comparison with V+M treatment. In conclusion, it is possible to cultivate maize using vermicompost as fertilizer because chemical characteristics, energetic parameters and amino acids prof ile in maize grain were not affected compared with the maize cultivated with vermicompost added with biofertilizers (V+M) or with corn cultivated with chemical fertilizers (CF).

Agave grijalvensis (B. Ullrich) was inoculated with Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe) and fertilized with different amounts of phosphorus (P) during plant development. Mycorrhizal colonization, fructan accumulation and fructosyltransferases enzymatic activities were determined. Glomus fasciculatum increased fresh weight of A. grijalvensis, the number of leaves, root length and fructan concentrations in stems and leaves. Phosphorus increased sucrose content, but reduced glucose and fructose concentrations in both leaves and stems. Activities of 1-fructosyltransferase (1-SST) (EC 2.4.1.99) and β-fructan-1-fructosyltransferase (1-FFT) (EC 2.4.1.100) were determined and explained due to different levels of fructans detected in A. grijalvensis plantlets.

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.)...

The aim of this protocol was for Bonellia macrocarpa hairy root establishment and bonediol production in transformed root cultures. Cotyledons, hypocotyls and roots were used as explants for hairy root induction. Fluorescence microscopy was used for detected tandem dimer of the tomato protein (TDT). A PCR analysis for rolC was used to confirm the presence of these genes. Identification and quantification of bonediol was made for HPLC. Hypocotyls showed greater transformation efficiency (25%). Fluorescence microscopy and PCR analysis confirm genetic transformation. Bonedio production was higher in hairy roots than in complete plants.

Olive trees are one of the most important oil crops in the world due to the sensorial and nutritional characteristics of olive oil, such as lipid composition and antioxidant content, and the medicinal properties of its leaves. In this paper, callus formation was induced using nodal segments of olive tree (Olea europaea cv. cornicabra) as explants. Fatty acid profile, total phenolic compounds and total flavonoid compounds were determined in callus culture after 15 weeks and compared with leaf and nodal segments tissues. There was no statistical difference in phenolic compounds among leaf, nodal segments and callus culture, whereas flavonoid compounds were higher in leaf. Fatty acid profile was similar in leaf, nodal segments and callus culture and was constituted by hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, cis-9,12-octadecadienoic acid, cis-9,12,15-octadecatrienoic acid. Hexadecanoic acid was the main fatty acid in callus, leaf and nodal segments with 35.0, 39.0 and 40.0% (w/w), of the lipid composition, respectively. With this paper, it is being reported for the first time the capacity of callus culture to accumulate fatty acids. Our results could serve to continue studying the production of fatty acids in callus cultivation as a biotechnological tool to improve different olive cultivars.

Factors such as slow growth, low rates of sexual and asexual reproduction, and viability of seeds among others limit the massive propagation of Agave americana L. by conventional methods. In this study, callus induction and shoot proliferation was determined in A. americana using Murashige and Skoog (MS) medium supplemented with dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA). Meristematic tissue was used as the explants, and were placed on MS medium supplemented with 30.0 g·L−1 sucrose with 0.11, 0.18, or 0.45 μm 2,4-D and 11.0, 22.0, 38.2, 44.0, 58.7, or 73.3 μm BA. Treatments were implemented according to factorial experimental design 3 × 6. After 1 month, the number of explants with callus was determined, whereas the numbers of shoots per explant were monitored after 4, 16, 20, and 36 weeks. The maximum percent of explants with callus was obtained with 0.11 μm 2,4-D and 58.7 and 73.3 μm BA, whereas the maximum numbers of shoots per explant (71) were obtained with 0.11 μm 2,4-D and 73.3 μm BA. The effect of different concentrations of indolebutyric acid (IBA) in the rooting of shoots was evaluated. There were no significant effects of IBA on the number of roots, root length, and axillary roots. Plantlets were acclimatized in the glasshouse and they did not show any phenotypic alteration. This is a highly efficient protocol for the in vitro propagation of A. americana via indirect organogenesis.

Los protocolos actuales para la micropropagacion de Agave americana L. tienen limitaciones para su aplicacion comercial debido al bajo numero de plantas producidas por cada explante. La organogenesis indirecta podria ser una alternativa, sin embargo, es necesario optimizar los reguladores de crecimiento vegetal para maximizar el numero de plantas. El objetivo del trabajo fue optimizar la concentracion de acido 2,4-diclorofenoxiacetico (2,4-D) y de 6-bencil adenina (BA) sobre la induccion de callos embriogenicos en A. americana usando meristemos apicales como explante para maximizar el numero de brotes por callo, utilizando un diseno experimental de superficie de respuesta. Se utilizo el medio Murashige Skoog (MS) adicionado con 30 g l-1 de sacarosa, y con 0,11;0,18; 0,45 o 2,26 μM de 2,4-D, y 11,0; 22,0; 38,2 o 44,0 μM de BA. Se implementaron 9 tratamientos con 3 repeticiones y el numero de brotes por callo fue evaluado despues de 4, 16, 20 y 36 semanas. Se indujo el enraizamiento in vitro usando medio MS adicionado con acido indolbutirico (AIB). Se obtuvo un maximo de 74 plantulas por callo, usando 2,26 μM de 2,4-D y 38,2 μM de BA. En conclusion, la organogenesis indirecta podria ser una alternativa para la micropropagacion de A. americana L con fines comerciales.

The aim of this investigation was to determine the effect of vermicompost and phosphate rock on plant growth, total phenols, flavonoids, flavanones, and antioxidant activity in Annona purpurea Moc & Sesse ex Dunal leaves. Annona purpurea seedlings were planted according to factorial 32 experimental design with nine repetitions. The factors were vermicompost (0, 50, and 100 g plant−1) and phosphate rock (0 and 10 g plant−1). Plant height, stem diameter, number of leaves, and chorophyll content were determined one month after application of the different treatments and total phenols, flavonols, flavanones, total flavonoids, and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity in dry leaves after 4 months. Plant height and stem diameter increased by phosphate rock, but not by vermicompost. Total phenols in leaves decreased by vermicompost. Flavonol content decreased by rock phosphate, whereas flavanones increased by vermicompost. Antioxidant activity decreased by vermicompost addition.

In the present study, the hexane, acetone and methanol extracts of stem, branches and roots from Crotalaria longirostrata were evaluated for their antifungal activity against Fusarium sp., Fusarium verticillioides and Aspergillus flavus. The variables analyzed were inhibition halos, mycelial growth inhibition, sporulation and minimum inhibitory concentration. Phytochemical analysis revealed the presence of saponins, coumarins, anthrones, anthraquinones, flavonoids and alkaloids on different organic extracts. The hexane extract showed zones of inhibition between 6.3 and 10.5 mm. The mycelia growth and sporulation of A. flavus were reduced to 90% with methanol extract. The minimum inhibitory concentration values obtained with hexane extracts were 6.75 mg mL-1 and with methanol extracts were 50 and 25 mg mL-1 for Fusarium strains. This is the first study reporting of phytochemical composition and biological activity of C. longirostrata that could be used as a natural alternative to control in vitro of certain important pathogenic fungi.

Worm-bed leachate is a nutrient-rich by-product of composting organic wastes with earthworms. Worm-bed leachate was stored and characterized while its possible antifungal activity towards the pathogenic fungus Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. was investigated in vitro. The pH decreased from 9.6 at the onset of the storage to 8.9 after 28 days, while the total N and C nearly halved. The surfactin concentration in the worm-bed leachate reached 10.8 μg L−1 at day 10, while that of iturin A and iturin A homologues increased towards the end of the storage. Sterilized worm-bed leachate had little effect on the growth of C. gloeosporioides, but unsterilized worm-bed leachate inhibited growth 100%. It was found that unsterilized worm-bed leachate inhibited growth of C. gloeosporioides, but sterilizing the worm-bed leachate strongly reduced the inhibitory effect indicating that the microorganisms in the worm-bed leachate out-competed the fungus for nutrients or were antagonistic towa...

Vermicompost and worm-bed leachate (WBL) are two products obtained from vermicomposting. The objective of this study was to evaluate the effect of different combinations of vermicompost and WBL on cultivating radish (Raphanus sativus L.). A multilevel factorial design with 25 treatments was used to investigate the effect of vermicompost at 0, 10, 20, 30, or 40% and WBL at 0, 10, 20, 30, or 40% on germination and growth parameters. A maximum seed germination of 54%, number of leaves (2.8), and plant height (8.6 cm) were obtained with 10% vermicompost and 10% WBL. A maximum shoot (7.0 g) and root (7.3 g) dry weight was obtained with 10% vermicompost and 15% WBL. Vermicompost and worm-bed leachate have an inhibitory effect at higher concentrations on seed germination and plant growth. These inhibitory effects might be due to increased salt concentrations, pH or auxin-like effects of humic and fulvic acids.

La leguminosa tropical Acaciella angustissima inoculada con o sin la cepa Sinorhizobium mexicanum ITTG R7T fue cultivada en un suelo tratado con (Al) para estudiar la tolerancia a este metal. Las plantas de A. angustissima fueron crecidas en el suelo con 0, 2, 4 y 6 mg de Al kg-1. Se hizo un seguimiento del efecto de Al e inoculacion en el crecimiento, la nodulacion, el contenido de nitrogeno y el contenido de taninos en las plantas. La altura, el peso seco total y el peso seco de la raiz de las plantas decremento significativamente cuando el suelo fue tratado con Al, pero incremento cuando fue inoculado. El Al disminuyo el numero de nodulos. El inoculo incremento el N total y el contenido de taninos de las plantas. En este experimento fue encontrado que el Al reduce el crecimiento de la leguminosa arbustiva tropical fijadora de N2 A. angustissima, mientras la inoculacion con S. mexicanum ITTG R7T estimula el crecimiento e incrementa el contenido de taninos y nitrogeno.

Jatropha curcas L. will be cultivated in large parts of the central highlands of Chiapas (Mexico) so that its seeds can be extracted for biofuel. Little is known how the cultivation of J. curcas, which contains phorbolesters, might affect soil processes. Soil was sampled at five locations and amended with leaves of J. curcas while dynamics of ammonium (NH4+), nitrite (NO2−) and nitrate (NO3−) and emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), well known greenhouse gasses, were monitored. If we considered no priming effect, then between 12 and 31% of the C added with Jatropha leaves mineralized within 56 days. However, the concentration of mineral N (sum of NH4+, NO2− and NO3−) did not increase in the Jatropha-amended soils compared to the unamended soils. The mean CO2 emission rate increased significantly 3.7 times when Jatropha leaves were added to the different soils. The N2O emission was low in the unamended soil and remained

Extracts of plants have been used to control pests, but little information exists about how effective they are to limit crop damage, or how they affect plant growth, crop yield and insects. Extracts from Azadirachta indica A. Juss. (L.) leaves (NEEM treatment), a plant originating from India known for its bio-insecticide characteristics, and Gliricidia sepium (Jacquin kunth ex Walp.) (GLIRICIDIA treatment), a plant originating from Mexico and Central America known to repel insects, were compared to a standard insecticide, lambda-cyalothrin or Karate ® (CHEMICAL treatment) for insect pest efficacy in cultivated maize in Chiapas, Mexico. Untreated maize plants served as control (CONTROL treatment). Plant damage, crop growth, yield and fauna were monitored during four growing seasons from 2003 to 2006. Mean maize yield was significantly higher in the NEEM and CHEMICAL treatments, i.e. 9784 and 9916 kg ha −1 , respectively, compared to the CONTROL treatment (7206 kg ha −1 ). The GLIRICIDIA treatment yielded 8747 kg ha −1 . Of the 26 insect species found during the growing season, only the number of Spodoptera frugiperda (Lepidoptera: Noctuidae), Macrodactylus spp. (Coleoptera: Melolonthidae) and Frankliniella spp. (Thysanoptera: Thripidae) was significantly different between the treatments, with the lowest values found in the chemical treated plots. The amount of beneficial insects was not affected by treatment, while the amount of insects that cause damage was significantly lower (ca. 2-fold) in the CHEMICAL treatment than in the other treatments. Mean damage to the newly formed leaves was 18% in the NEEM treatment and 23% in the GLIRICIDIA treatment and significantly lower than that of the CONTROL treatment (37%), but significantly higher than that of the CHEMICAL treatment (11%). It was found that leaf extracts of G. sepium and A. indica reduced damage to the newly formed leaves and increased yields compared to untreated maize plants, with neem being more effective. However, neem was not as effective as chemical control with lambda-cyalothrin, for overall maize protection.

An orthogonal experimental design L9 (34) in triplicate was used to optimize the osmotic drying process of jicama or Yam bean (Pachyrhizus erosus). The effect of sucrose content, temperature, time of submerging and thickness of the fruit, on the osmotic drying process of Yam bean were tested. Maximal water loss was obtained when 10 mm fruit slices were submerged in a sucrose concentration of 60° Brix maintained at 60 °C for 2 h, while maximum impregnation was obtained when 5-mm slices were submerged in a 50° Brix solution maintained at 60 °C for 6 h.

Native rhizobia are ideal for use as commercial legume inoculants. The characteristics of the carrier used to store the inoculants are important for the survival and symbiotic potential of the rhizobia. The objective of this study was to investigate the effects of peat (PEAT), perlite sugarcane bagasse (PSB), carboxymethyl cellulose plus starch (CMCS), and yeast extract mannitol supplemented with mannitol (YEMM) on the survival, nodulation potential and N2 fixation capacity of the native strains Sinorhizobium mexicanum ITTG R7T and Rhizobium calliandrae LBP2-1T and of the reference strain Rhizobium etli CFN42T. A factorial design (4 × 3) with four repetitions was used to determine the symbiotic potential of the rhizobial strains. The survival of the strains was higher for PEAT (46% for strain LBP2-1T, 167% for strain CFN42T and 219% for strain ITTG R7T) than for the other carriers after 240 days, except for CFN42T kept on CMCS (225%). All the strains kept on the different carriers effectively nodulated common bean, with the lowest number of nodules found (5 nodules) when CFN42T was kept on CMCS and with the highest number of nodules found (28 nodules) when ITTG R7T was kept on PSB. The nitrogenase activity was the highest for ITTG R7T kept on PEAT (4911 μmol C2H4 per fresh weight nodule h−1); however, no activity was found when the strains were kept on YEMM. Thus, the survival and symbiotic potential of the rhizobia depended on the carrier used to store them.

An efficient and reproducible protocol for regeneration of plantlets at a high frequency was developed by using sugar cane buds. Disinfected buds were firstly submerged in ethanol sodium hypochlorite solution with 0.1 % polyvinylpyrrolidone, 1.5 % ascorbic acid and 1.75 % citric acid as antioxidants and subsequently treated with solution of agrimicin:captan (1:1). The upper stalk segment was better to obtain bud in vitro culture compared to lower segments. The medium for induction of multiple shoots consisted of Murashige and Skoog basal medium (MS) supplemented with 2 mg dm−3 thidiazuron and 1 mg dm−3 naphthalene acetic acid. An average of 24 shoots per bud was obtained for cv. Mex 68-P23 within four weeks and 29 shoots for cv. MY 55-14 within six weeks. Indole-3-butyric acid induced more roots in both cultivars compared to the untreated plantlets. Plantlets transferred to soil showed normal growth with up to four axilliary buds in each node. It was concluded that the germplasm obtained through the above mentioned technique generated stalks with more buds in each node which would give farmers more vegetative material for plantations in field with 100 % germination.

The activities of sucrose phosphate synthase (SPS), sucrose synthase (SUSY), neutral invertase (NI) and soluble acid invertase (SAI) were measured in callus cultures of four Mexican sugarcane cultivars (Saccharum spp.) with a different capacity to accumulate sucrose in stem parenchyma cells. The results indicated that sucrose accumulation in callus was positively correlated to the activity of SPS and SUSY and negatively to the activity of SAI and NI while SPS explained most of the variation found for sucrose accumulation and NI least.

Summary Field germination of Acacia angustissima (Mill.) Kuntze, a N2-fixing tree whose bark is traditionally extracted for tannins used in the leather industry, takes up to 55 days and the percentage of germination is generally less than 20%. Abrasion, dry or wet heat, or immersing the seeds in different concentrations of sulphuric acid, chloric acid or hydrogen peroxide for different lengths of time, were tested as germination enhancers. The application of dry heat resulted in < 37% germination, less than the 44% found for untreated control seeds. The application of wet heat for ≤ 30 s and abrasion for 1200 s resulted in 69% germination. Immersing seeds in concentrated H2SO4 for 900 s resulted in 77% germination while diluting H2SO4 or longer exposure to concentrated H2SO4 decreased it. Immersing the seeds in concentrated or diluted H2O2 also increased germination, but to a lesser extent than when immersed in H2SO4. We found that the exposure of seeds of A. angustissima to concentrated H2SO4 for 900 s appeared to be the best technique to stimulate their germination; the treatment gave the largest percentage of germination in the shortest time, the technique is easy to apply and many seeds can be treated at once.

Organic fertilization and crop association are two agroecological management practices that have the potential to optimize land use in horticultural production. The objective of this study was to evaluate the effect of Bokashi and Bokashi amended with Vermicompost Leachate (VL) on the growth, yield and quality of jalapeno pepper ( Capsicum annuum L.) and onion ( Allium cepa L.) in monoculture and intercropping cultures. This work was conducted under rainfed conditions in the community of Santa Rosa el Oriente, a municipality of Trinity, Chiapas. A randomized complete block design in a split plot arrangement with six treatments and four replicates by treatment was used. Bokashi significantly increased the number of leaves and plant height in onion (37 and 62%) and jalapeno pepper (133 and 94%) compared with the control plants. In jalapeno pepper and onion, the content of capsaicin and soluble solids was 41 and 42% higher with the application of Bokashi plus VL, respectively. In onion, Bokashi increased the polar and equatorial diameters and bulb weight by 28, 69 and 269%, respectively, and its yield increased from 6.4 to 21.0 t ha -1 . The land equivalent ratio (LER) was 1.34 to 1.55, which indicated that intercropping was advantageous on monoculture, regardless of the fertilization type. Therefore, the application of Bokashi and crop association favored the yield and quality of jalapeno pepper and onion with an efficient use of the land. La fertilizacion organica y la asociacion de cultivos son dos practicas de manejo agroecologico con el potencial de optimizar el uso de la tierra en la produccion horticola. El objetivo de este estudio fue evaluar el efecto de Bokashi y Bokashi adicionado con Lixiviado de Vermicomposta (LV) sobre el crecimiento, rendimiento y calidad de chile jalapeno ( Capsicum annuum L.) y cebolla ( Allium cepa L.) cultivados en monocultivo y en policultivo. El experimento se realizo bajo condiciones de temporal en la comunidad Santa Rosa el Oriente, La Trinitaria, Chiapas. Se utilizo un diseno de bloques completos al azar con un arreglo de parcelas divididas con seis tratamientos y cuatro repeticiones por tratamiento. Bokashi incremento significativamente el numero de hojas y la altura de la planta en cebolla (37 y 62%) y chile jalapeno (33 y 94%) en comparacion con las plantas control. En chile jalapeno y cebolla el contenido de capsaicina y solidos solubles fueron 41 y 42% mas altos con la aplicacion de Bokashi adicionado con VL, respectivamente. En cebolla Bokashi incremento 28, 69 y 269% los diametros polar y ecuatorial y el peso del bulbo. Con la aplicacion de Bokashi el rendimiento de cebolla incremento de 6.4 a 21 t ha -1 . Se obtuvo una relacion equivalente de tierra (RET) de 1.34 a 1.55, indicando que el policultivo fue ventajoso sobre el monocultivo, indistintamente del tipo de fertilizacion. Por lo tanto, la aplicacion de Bokashi y la asociacion de cultivos favorecieron el rendimiento y la calidad de chile jalapeno y cebolla con un eficiente uso de la tierra.

The objective of this study was to investigate the effect of vermicompost, worm-bed leachate (WBL) and Glomus mosseae, an arbuscular mycorrhizal fungi (AMF), on growth of lemongrass ( Cymbopogon citratus (DC.) Stapf). A response surface methodology, i.e . a three-level Box Benhen design with three repetitions and three blocks, was applied to optimize biomass production, essential oil yield and its composition. Application rates of Glomus mosseae were 0, 1 or 2 g plant -1 , vermicompost 0, 5 or 10 g plant -1 and WBL 0, 10 and 20%. The AMF had no significant effect on the variables tested, but vermicompost had a significant effect on essential oil yield and WBL on essential oil yield, myercene concentration and shoot dry weigh (p G. mosseae , 5.0 g vermicompost and 20% worm-bed leachate would yield 0.797% essential oil of which 62.6% was citral.

The effects of different inorganic fertilizers and rhizobial inoculation on shoot height, total shoot and root dry weight, nodule number, total shoot nitrogen, nitrogenase activity and tannic acid content of Acaciella angustissima (Mill.) Britton & Rose were investigated in the laboratory. Seedlings were grown in a climate chamber in glass tubes containing sterilized mixture of vermiculite and peat moss, and treated with combinations of nitrogen (N) at 45 mg plant¹, phosphorus (P) at 30 mg plant¹, potassium (K) at 20 mg plant¹ and inoculated with the bacterium Sinorhizobium mexicanum. The combined applications of N, P or K to uninoculated plants increased shoot height and dry weight as compared to the unamended plantlets. The tannin content in uninoculated plants was highest when amended with P+K. Treatment had a significant effect on plant growth, nodulation and tannin content varied. The plants treated with P + K + S. mexicanum had significantly longer shoot height, total shoot and root dry weight, nodule number, total shoot nitrogen, nitrogenase activity and tannic acid content in comparison with unamended plants. It was found that N reduced number of nodules, tannin content and nitrogenase activity of A. angustisisma. As such, farmers should refrain from applying N fertilizer, but could apply P and K to maximize tannin production in A. angustissima. Se investigaron en el laboratorio los efectos de diferentes fertilizantes inorgánicos y la inoculación rizobial sobre la altura de planta, peso seco total de planta, peso seco de raíz, el número de nodulos, el nitrógeno total de la planta, la actividad de la nitrogenasa y el contenido de ácido tánico de Acaciella angustissima (Mili.) Britton & Rose. Las plántulas fueron crecidas en una cámara climática en tubos de vidrio conteniendo una mezcla de vermiculita y turba, y tratadas con las combinaciones de nitrógeno (N) en 45 mg planta"¹, fósforo (P) en 30 mg planta"¹, potasio (K) en 20 mg planta"¹ e inoculado con la bacteria Sinorhizobium mexicanum. La combinación de las aplicaciones de N, P o K en plantas sin inocular incrementa la altura y el peso seco de planta en comparación con las plantas sin tratamiento. El contenido de taninos en plantas no inoculadas fue el más alto cuando suplementamos con P+K. El tratamiento tuvo un efecto significativo sobre el crecimiento de planta, modulación y el contenido de tanino variado. Las plantas tratadas con P + K + S. mexicanum tuvieron significativamente mayor altura de planta, peso seco total de planta, peso seco de raíz, el número de nodulos, nitrógeno total de planta, actividad de la nitrogenasa y contenido de taninos en comparación con las plantas sin suplementar. Fue encontrado que el N reduce el número de nodulos, el contenido de taninos y la actividad de la nitrogenasa de A. angustisisma. Como tal, los agricultores deberían abstenerse de aplicar el fertilizante de N, pero podrían aplicar P y K para maximizar la producción de tanino en A. angustissima.

El objetivo del trabajo fue evaluar el efecto de dos hongos micorrizicos arbusculares (HMA) a diferentes concentraciones de fosforo sobre la sobrevivencia y el crecimiento de plantulas de pina {Ananas comosus (L.) Merr.) obtenidas por micropropagacion. Las plantulas se multiplicaron masivamente en cultivos in vitro y se aclimataron gradualmente bajo un esquema de estres por temperatura en tres etapas secuenciales. Los efectos de los HMA y el fosforo no fueron significativos sobre la sobrevivencia y la altura de las plantulas, sin embargo, Glomus claroideum estimulo que las plantulas tuvieran mayor numero de hojas y peso seco. Los resultados sugieren que la altura de las plantulas fue mayor cuando fueron cultivadas con G. claroideum y 0,9 mM de fosforo.

The survival rate, shoot and root dry mass, shout number, plant growth, stem height and diameter, number of leaves and root length were measured in micropropagated plantlets of Alpinia purpurata (Red ginger) inoculated with Azospirillum sp. 11B and Azotobacter sp. Pachaz 008 at 10(7), 10(8) and 10(9) cells cm(-3) using a complete randomized experimental design. Inoculation ofA. purpurata plantlets with the Azospirillum sp. 11B or Azotobacter sp. PACHAZ 008 strains induced larger stem diameter, root dry mass, number of shoots and increased their survival rate from 77 to 100% compared to plantlets without inoculation, while other plant characteristics were not affected.