Introduction
⌅Moringa oleifera Lam. (moringa, ben oil tree, drumstick tree, malunggay and miracle tree) is the best known of the 13 species identified within Moringa genus (Font Quer 1975Font Quer, P. 1975. Diccionario Botánico. Edit. Labor S.A. Barcelona. 1244 p. ISBN: 84-335-5804-8.). It stands out for its multiple uses and adaptation to different soil and climate conditions, making it an option for feeding livestock. This plant grows between one and two meters per year and reaches up to 12 m in height in the first three or four years (Pina et al. 2018Pina, J.C., Oliveira, AKMd., Matias, R. & Silva, Fd. 2018. Influência de diferentes substratos na produção de fitoconstituintes de Moringa oleifera lam. cultivada a pleno sol. Ciência Florestal, 28: 1076-1087, ISSN: 1980-5098.). Generally, it grows well without applying high amounts of fertilizers. However, to improve growth and yield, organic or mineral fertilization is necessary (Guzmán-Albores et al. 2019Guzmán-Albores, M.J., Ramírez-Merchant, M.L., Interiano-Santos, E.C., Manzano-Gómez, L.A., Castañón-González, J.H., Winkler, R., Abud Archila, M., Montes-Molina, J., Gutiérrez-Miceli, F. & Ruíz-Valdiviezo, V. 2019. Metabolomic and Proteomic Analysis of Moringa oleifera Cultivated with Vermicompost and Phosphate Rock under Water Stress Conditions. International Journal of Agriculture & Biology, 21(4): 786-794, ISSN: 1814-9596. https://doi.org/10.17957/IJAB/15.0957.). The need to shorten the nursery periods should be considered, because a phenological development, adequate for its transplantation to the field in 45 to 60 d (Oquendo 2014Oquendo, G. 2014. Descripción, establecimiento y uso de las principales arbóreas: Moringa oleifera. En: Uso de arbóreas como recurso sostenible para la crianza animal. Ed.: José M. Argenter, Holguín. Cuba. 112 p.), is achieved with conventional methods.
Plana et al. (2016)Plana, R.R., González, P.J. & Soto, F. 2016. Combined use of EcoMic®, Fitomas-E® and mineral fertilizers in the forage production of animal food based in triticale (x. Triticosecale Wittmack), cv. INCA TT-7. Cultivos Tropicales, 37(4): 76-83, ISSN: 1819-4087. pointed out that the use of arbuscular mycorrhizal fungi (AMF) leads to a symbiosis of the microorganism with the plant, which allows the transport of necessary nutrients for its metabolism and improves the chemical, physical and biological properties of soil. Mycorrhizal fungi are the main organisms associated with Moringa spp. (Knopf et al. 2013Knopf, E., Blaschke, H. & Munch, J. 2013. Improving Moringa Growth by Using Autchthonous and Allochthonous Arbuscular Mycorrhizal Fungi in Lake Victoria Basin. West African Journal of Applied Ecology, 21(1): 47-57, ISSN: 2661-9040.). According to Pita (2014)Pita, A. 2014. Efecto de Glomus fasciculatum Tul., en la nutrición y el crecimiento de Moringa oleifera Lam, en un suelo Fersialítico Rojizo Ócrico Eútrico. Tesis presentada en opción al grado científico de Doctor en Ciencias Forestales. Universidad de Pinar del Río, Pinar del Río, Cuba. 112 p., Glomus fasciculatum Tul. establishes mycorrhizal association with M. oleifera, which places this species among those that establish symbiosis with endomycorrhizas.
Various natural products are used to enhance the ecological management of agroecosystems, including biopesticides, phytostimulants and biostimulants (Núñez 2018Núñez, D. 2018. Efecto de bioestimulantes agrícolas en la supervivencia y el crecimiento de plantas in vitro de caña de azúcar (Saccharum spp.) en la fase de aclimatización ex vitro. Tesis presentada en opción al título académico de Máster en Ingeniería Agrícola. Universidad Central ʺMarta Abreuʺ de Las Villas, Facultad de Ciencias Agropecuarias. 78 pp.). VIUSID® AGRO is one of the synthetic biostimulants applied to crops in Cuba, which contains nitrogen and free amino acids in its chemical composition, elements that play an essential role in the formation of proteins and facilitate their easy absorption into the plant (Simbaña 2011Simbaña, C.C.L. 2011. Estudio de las propiedades físicas y funcionales de un hidrolizado enzimático de proteína a escala piloto y su aplicación como fertilizante. Available at: http://bibdigital.epn.edu.ec/bitstream/15000/3762/1/CD-3535.pdf. Consulted: May 20, 2014). Another available biostimulant is TOMATICID, a commercial product that contains 0.14 w/v of 4-chloro phenoxyacetic acid (4-CPA). This product acts as a plant growth regulator and allows very good fruiting in tomato plants, at the same time that it causes an advance in the ripening of fruits (Lamí-Izquierdo et al. 2011Lamí-Izquierdo, L., Díaz-Luzbet, M., García-Bassa, C., Mesa-Jardín, M., Cabrera-Lejartí, M., Lores-Nápoles, M.N., Crespo-Zayas, D. & Álvarez-Delgado, A. 2011. Obtención y generalización del empleo de uma fitohormona sintética para aumentar el rendimento del tomate y otros frutos. ICIDCA. Sobre los derivados de azúcar, 45(2): 10-18, ISSN: 1025-3076.). No references were found from other authors on the application of these biostimulants to improve the germination of moringa seeds.
The objective of this research was to evaluate the stimulating effect of EcoMic®, VIUSID® AGRO and TOMATICID on germination and initial development of M. oleifera for its future application in the nursery phase.
Materials and Methods
⌅Experimental procedure
⌅The experiment was carried out in polyurethane foam trays, in a glass house, where seedlings grew under natural light conditions in a chamber of 2500 to 3500 lux, with temperatures of ± 27 ºC. The relative humidity was 75/85 %. Four seeds were sown in each little well, containing 120 g of substrate. It was planted 1 cm deep. The start of germination was considered when the radicle had a minimum length of 2 mm. Seeds were soaked for 24 h prior to sowing, according to the methodology of Padilla et al. (2012)Padilla, C., Fraga, N. & Suárez, M. 2012. Efecto del tiempo de remojo de las semillas de moringa (Moringa oleifera) en el comportamiento de la germinación y en indicadores del crecimiento de la planta. Cuban Journal of Agricultural Science, 46(4): 419-421, ISSN: 2079-3480..
Substrate characteristics
⌅The used substrate was formed with 40 % organic matter and 40 % brown soil, without differentiation of carbonates and 20 % river sand. Table 1 shows its chemical characteristics.
Sample | Na | K | Ca | Mg | P, mg/kg | OM, % | pH, H2O |
---|---|---|---|---|---|---|---|
cmol/kg | |||||||
Solid substrate | 0.15 | 0.47 | 10.9 | 2.0 | 258 | 5.29 | 7.0 |
TOMATICID
⌅This product, which contains 0.14 w/v of 4-chloro phenoxyacetic acid (4-CPA), was applied at a concentration of 10 mL/L H2O, at a rate of 1 mL per seed at the time of sowing (TS) and after five days of sowing (DAS), depending on the treatment.
VIUSID® AGRO
⌅This product was applied at a concentration of 1 mL/L H2O, at a rate of 1 mL per seed, at TS and at five DAS, depending on the treatment.
Mycorrhizal inoculant
⌅The EcoMic® product was used, formulated from the arbuscular mycorrhizal fungal (AMF), INCAM4 strain (Glomus cubense). For its application, a certified solid inoculant was used, containing 25 spores/g of the substrate sold by the company LABIOFAM SA. For this purpose, the recommendations of the manufacturer were followed. It was applied at a rate of 5 g/little well at the time of sowing or at five DAS (according to the treatment), then it was irrigated (10 mLH2O/little well).
Experimental design and statistical analysis
⌅A completely randomized design was applied, with 10 treatments (table 2) and 10 repetitions, for 10 little wells per treatment in total and 100 little wells in each experimental unit (three units, with 300 little wells). The units consisted of three blocks of polyurethane foam trays, with the same number of treatments and repetitions. Once the assumptions of normality and homogeneity of variance for the application of parametric tests were verified, an ANOVA analysis was performed. Differences between means were determined by the LSD of Fisher. Percentage data were transformed by 2arcosin√P. The statistical program StatGraphics Centurion XV (Anon 2007Anon. 2007. Statgraphics centurion XV. Dyna, 82(1): 7, ISSN: 0012-7361.) was used.
Number | Treatments |
---|---|
1 | Absolute control |
2 | Chemically fertilized control |
3 | EcoMic® (TS) |
4 | TOMATICID 10 mL/L (TS) |
5 | VIUSID® AGRO 1mL/L (TS) |
6 | EcoMic® (TS) + TOMATICID (TS) |
7 | EcoMic® (TS) + VIUSID® AGRO (TS) |
8 | EcoMic® (TS) + VIUSID® AGRO (TS) + TOMATICID (TS) |
9 | EcoMic® (TS) + TOMATICID (five DAS) |
10 | EcoMic® (TS) + VIUSID® AGRO (five DAS) |
Chemical fertilization
⌅The fertilized control consisted of an application of 23.84 mg of NH4NO3/little well, equivalent to 150 kgN/ha.
Cumulative and total germination percentage (PGA, %), at five DAS, 10 DAS, 15 DAS and 20 DAS according to the formula PG: NSG/NSS x 100 (Ede et al. 2015Ede, A.E., Ndubuaku, U.M. & Baiyeri, K.P. 2015. Media Effects on Emergence and Growth of Moringa (Moringa oleifera Lam) Seedlings in the Nursery. American Journal of Experimental Agriculture, 7(3): 182–189, ISSN: 2231-0606. https://doi.org/10.9734/AJEA/2015/13602.)
Where:
NSG: number of germinated seeds
NSS: number of sown seeds
Partial germination percentage (PGP, %) at five DAS, 10 DAS, 15 DAS and 20 DAS according to the formula (Ede et al. 2015Ede, A.E., Ndubuaku, U.M. & Baiyeri, K.P. 2015. Media Effects on Emergence and Growth of Moringa (Moringa oleifera Lam) Seedlings in the Nursery. American Journal of Experimental Agriculture, 7(3): 182–189, ISSN: 2231-0606. https://doi.org/10.9734/AJEA/2015/13602.)
Where:
NSGti: number of seeds germinated in ti (time in which the seeds were sprout).
NSS: number of sown seeds
Index of phase germination (IG), according to the formula (Islam et al. 2012Islam, S., Mia, A.B., Hossain, J., Ahmed, J., Uddin, S.J., Haider, I. & Khan, M.A. 2012. Priming on embryo emergence and seedling vigor of small fruited bitter gourd (Momordica charantia L.) under suboptimal temperature. Agricultural and Food Sciences, 2: 1-10, ISSN: 0975-9107.)
Where:
ti: days elapsed since sowing
ni: number of seeds germinated in ti
N: total seeds
Total germination index (IG), according to the formula Scott et al. (1984)Scott, S.J., Jones, R.A. & Williams, W.A. 1984. Review of data analysis methods for seed germination. Crop Science, 24: 1129-1199, ISSN: 1435-0653. https://doi.org/10.2135/CROPSCI1984.0011183X002400060043X.:
Where:
ti: days elapsed since sowing (sum of time periods)
ni: number of germinated seeds in ti (sum of germinated seeds in each period)
N: total seeds
Germination speed index (IVG), according to the formula of Terry et al. (2014)Terry, E., Ruiz, J., Tejeda, T. & Reynaldo, I. 2014. Efectividad agrobiológica del producto bioactivo Pectimorf® en el cultivo del Rábano (Raphanus sativus L.). Cultivos Tropicales, 35(2): 105-111, ISSN: 1819-4087.:
Where:
ni: number of seeds germinated in you ti
ti: time elapsed since sowing
Inoculation efficiency index (IEI, %) based on the final cumulative germination percentage (PG), according to the formula of Santillana et al. (2012)Santillana, N., Zúñiga, D. & Arellano, C. 2012. Capacidad promotora del crecimiento en cebada (Hordeum vulgare) y potencial antagónico de Rhizobium leguminosarum y Rhizobium etli. Agrociencia Uruguay, 16: 11-17, ISSN: 2730-5066.:
Where:
TI: PG of inoculated treatment
CA: PG of absolute control
Results and Discussion
⌅In the five DAS phase (figure 1), the fertilized treatment was superior to the absolute control and the inoculated treatments, although it shared letters with treatment 3
In this phase, most of the inoculated treatments did not present germination, except those where EcoMic® (sowing) and each biostimulant were applied at five DAS. There were no significant differences among the germinated treatments, neither with the fertilized control nor with the negative control. It is interesting to note that the absolute control, as well as the fertilized control and three of the inoculated treatments, presented germination in this phase. Meanwhile, the rest of the inoculated treatments did not germinate. This could be associated with an initial inhibition of germination due to the effect of absicic acid (ABA) (Posada et al. 2021Posada, L.F., Moreno, A.E., Santos, M.T. & Estrada, G.A. 2021. Mecanismos de promoción de crecimiento de las PGPB. Pp. 80-104. En: Bacterias promotoras de crecimiento vegetal en Sistemas de Agricultura Sostenible. Ruth Bonilla Buitrago, Luz Estela González de Bashan, Raúl Osvaldo Pedraza (Eds.). Corporación colombiana de investigación agropecuaria – Mosquera (Colombia): AGROSAVIA. 372 p. ISBN E-book: 978-958-740-501-9. ISBN: 978-958-740-500-2.), caused by the presence of AMF in some treatments. However, this possibility has not yet been defined because the changes in hormonal levels in plants when inoculated seem to depend on the type of AMF and the plant species (Bernardo et al. 2020Bernardo, V., Garita, S., Ripodas, J. I., González, M., Arango, C. & Ruscitti, M. 2020. Micorrizas arbusculares, aplicaciones en el sector agro-forestal. Pp. 64-88. En: Micorrizas arbusculares. Biología y aplicaciones en el sector agro-forestal. Mario Carlos Nazareno Saparrat, Marcela Fabiana Ruscitti y Maria Cecilia Arango (coordinadores). EDULP. Libro digital. 135 p. ISBN 978-987-8348-41-4.). Noguera-Talavera et al. (2018)Noguera-Talavera, A., Reyes-Sánchez, N. & Mendieta-Araica, B. 2018. Guía de establecimiento vivero moringa (Moringa oleifera). Manejo de viveros de Marango. Guía Técnica N°21. Una alternativa sostenible de alimentación animal ante el cambio climático. Universidad Nacional Agraria Promarango. 27 p. state that moringa germination begins on the third day with the highest number of germinations between 9 and 11 d. These results also contradict Cadillo (2022)Cadillo, G.A. 2022. Efecto de bioestimulantes en las características agronómicas del cultivo de Moringa (Moringa oleifera) bajo condiciones de vivero en Vegueta- Huaura. Tesis en opción al título de Ingeniero Agrónomo. Universidad Nacional José Faustino Sánchez Carrión. Facultad de ingeniería agraria, industrias alimentarias y ambiental. Huacho, Perú. 126 p., who obtained, under nursery conditions, emergence percentages of 61 to 85 % at seven DAS for M. oleifera seeds, treated with different synthetic biostimulants.
The accumulated germination at 10 DAS (figure 2) showed that treatment 10 was superior (p<0.05) to absolute control and treatments 3, 4, 5 and 7, but had equal letters with respect to treatments 6, 8 and 9. Regarding partial germination, treatments 10, 8 and 6 were superior (p<0.05) to the rest, except for 9, with which they shared the same letters.
In the germination phase at 10 DAS, the effect of the inoculated treatments is better defined. In partial germination, the fertilized control was inferior to the treatments that stood out, a fact that indicates the superior effect of the bioproducts on germination in this phase. The common denominator for these treatments is the application of EcoMic®, which contains Glomus cubense. This genus of fungus is well known for its effect on increasing the germination of different species (Wasy et al. 2010Wasy, A.A., Shyanmalamma, S. & Nache, G.V. 2010. Influence of bio-inoculants on nursery establishment of papaya cv Solo. Acta Horticulturae, 851: 389-394, ISSN: 2406-6168.). Ballina et al. (2017)Ballina, H.S., Ruiz-Sánchez, E., Ambriz, E. & Alvarado, C.J. 2017. Efecto de la luz y micorrizas en la germinación de semillas de árboles de selvas secas. Madera y Bosques, 23(3): 29-37, ISSN: 2448-7597. https://doi.org/10.21829/myb.20117.2331531. reported the superior effect of AMF Glomus intraradice on the germination of Senna racemosa and Bahuinia forficata (both belonging to the Fabaceae family).
In the case of treatment 10, in addition to EcoMic®, VIUSID® AGRO was applied to the sowing at five DAS. This compound is known because of its high content of amino acids (alanine, glycine, glutamic acid, proline and arginine). This last amino acid constitutes 40% of proteins in seeds. Angelovici et al. (2011)Angelovici, R., Fait, A., Fernie, A.R. & Galili, G. 2011. A seed high-lysine trait is negatively associated with the TCA cycle and slows down Arabidopsis seed germination. New Phytologist, 189(1): 148–159, ISSN: 1469-8137. https://doi.org/10.1111/j.1469-8137.2010.03478.x. pointed out that proteins in seeds are not only an important source of amino acids during germination, they are also essential for energy production, so the importance of this amino acid in the germination results of M. oleifera is not ruled out.
The application of TOMATICID did not show a significant effect as in the inoculation of EcoMic® with VIUSID® AGRO. However, in the values obtained with treatment 6 (EcoMic®, ST + TOMATICID, ST), as well as with treatment 9 (EcoMic®, ST + TOMATICID, five DAS), in partial and accumulated germination, it was observed that they share letters with the treatments that had the greatest effect, so the influence of the 4-chloro phenoxyacetic acid contained in TOMATICID is not rejected. According to Barberá (1989)Barberá, C. 1989. Pesticidas agrícolas. Productos de acción fisiológica. 4ta edición. Ediciones Omega S.A. Barcelona. 350 p., many applications replace naphthaleneacetic acid and indoleacetic acid (important hormones for cell division), due to the occasional irregular results of these last two compounds.
In the 15 DAS phase (figure 3), the accumulated germination showed that absolute control, as well as the fertilized treatment, were superior (p<0.05) to treatments 3, 5 and 9, although they shared the same letters with the rest. In partial germination, the absolute control was superior (p<0.001) to the other treatments, except the fertilized one and 7, which had statistical similarity.
The 15 DAS phase showed germination marked by lower values of the inoculated treatments compared to the absolute control and the fertilized control in partial germination, except in treatment 7. Also, in this phase, the fertilized control and the negative control are equal in their values. Regarding cumulative germination, although the values of inoculated treatments are mostly equal to the fertilized control, they also do so with the absolute control. These results contradict what Noda and Castañeda (2012)Noda, Y. & Castañeda, L. 2012. Efecto de EcoMic® en la emergencia de plántulas de Jatropha curcas (Nota Técnica). Pastos y Forrajes, 35(4): 401-406, ISSN: 2078-8452. reported, who obtained the highest percentage of germination at 15 and 16 DAS in Jatropha curcas seeds (Euphorbiaceae family), when inoculating them with EcoMic®. However, Serbelló et al. (2014)Serbelló, F.G., Mesa, J. R. & Soto, R. 2014. Efecto de diferentes alternativas biológicas, sobre el porcentaje y velocidad de germinación de las semillas de fruta bomba (Carica papaya L.). Revista Científica Agroecosistemas, 2(1): 247-253, ISSN: 2415-2862. demonstrated the inhibitory effect of Glomus fasciculatum on seeds of Carica papaya L. (Caricaceae family) in the first days after sowing, although this effect decreases until reaching a germination percentage similar to the rest of the treatments after 28 d. This result should be further studied in other experiments, due to its physiological basis.
There are no references to the effect of TOMATICID and VIUSID® AGRO in this phase of the variable under study. Inferior values of the treatments inoculated with said bioproducts, as well as the statistical similarity of the fertilized control with the control, could be attributed to insufficient mobilization of the compounds from the seed reserve in this phase.
At 20 DAS (figure 4), in the accumulated germination, treatment 10 was superior (p<0.001) to the rest, except for the fertilized control and treatment 8. In the partial, it was also found that treatment 10 and 8 were superior (p<0.001) to the rest, except for the fertilized control, with which they shared the same letters.
With respect to the inoculation efficiency index based on the final accumulated germination (IEI, %) in the 20 DAS phase (figure 5), treatments 10 and 8 presented positive values in their IEI, while it was negative in the rest.
In this last phase of germination, it was observed that the greatest effect of bioproducts occurred in the treatments where EcoMic® was applied at sowing and VIUSID® AGRO at five DAS. This was followed by the application of the three bioproducts at the same time, during sowing (figure 4). Note that these treatments, which presented a higher IEI (figure 5), included EcoMic® combined with VIUSID® AGRO. The treatment in which EcoMic® (ST) + VIUSID® AGRO (five DAS) was applied was considered to have high efficiency. Hernández (2016)Hernández, S.A.H. 2016. Efecto de la aplicación de Biozyme TF sobre la germinación de semilla de Moringa oleifera Lam. Tesis de Licenciatura. Universidad Autónoma Agraria Antonio Narro, Buenavista, Saltillo, Coahuila, México. 65pp. assured that the application of the biostimulant Biozyme TF (hormonal complex of gibberellin, auxin and cytokinin-zeatin) had a superior effect on the final germination of M. oleifera seeds.
The application of EcoMic®, as well as VIUSID® AGRO, showed the high efficiency of these bioproducts. The effect of EcoMic® on this variable coincides with Noda and Castañeda (2012)Noda, Y. & Castañeda, L. 2012. Efecto de EcoMic® en la emergencia de plántulas de Jatropha curcas (Nota Técnica). Pastos y Forrajes, 35(4): 401-406, ISSN: 2078-8452., who considered that the use of EcoMic® as seed inoculum could be a satisfactory practice to obtain good emergence percentages, which would represent a greater number of seedlings in relatively short periods of time. Reyes-Pérez et al. (2021)Reyes-Pérez, J.J., Rivero-Herrada, M., Andagoya-Fajardo, C.J., Beltrán-Morales, F.A., Hernández-Montiel, L.G., García Liscano, A.E. & Ruiz-Espinoza, F.H. 2021. Emergencia y características agronómicas del Cucumis sativus a la aplicación de quitosano, Glomus cubense y ácidos húmicos. Biotecnia, 23(3): 38-44, ISSN: 1665-1456. also found that the percentage of highest emergence in Cucumis sativus seeds (Cucurbitaceae family) was shown with the application of Glomus cubense. However, Bover-Felices et al. (2017)Bover-Felices, K., López-Vigoa, O., Rizo-Álvarez, M. & Benítez-Álvarez, M.Á. 2017. Efecto del EcoMic® y el Pectimorf® en el crecimiento de plántulas de Leucaena leucocephala cv. Cunningham. Pastos y Forrajes, 40(2): 102-107, ISSN: 2078-8452. did not obtain superior results in the emergence of seeds of Leucaena leucocephala (Fabaceae family), when inoculating them with G. cubense. Knopf et al. (2013)Knopf, E., Blaschke, H. & Munch, J. 2013. Improving Moringa Growth by Using Autchthonous and Allochthonous Arbuscular Mycorrhizal Fungi in Lake Victoria Basin. West African Journal of Applied Ecology, 21(1): 47-57, ISSN: 2661-9040. observed that M. oleifera seeds, sown in soils with a high population of AMF, had better germination than seeds sown in soils with a low population of these fungi.
The high zinc content in VIUSID®AGRO favors the formation of new tissues and, specifically, germination (Catalysis 2016). It is noteworthy that, although the application of EcoMic® did not favor seed germination in other treatments in this last phase, the combination of this biofertilizer at the time of sowing with VIUSID® AGRO at five DAS showed a synergistic effect superior to the other combinations. However, the presence of TOMATICID had no marked influence on this variable.
It should be stated that low germination percentages were obtained, even in the best treatments. This can be related to the quality of the seed used, which could have lost its viability due to the storage time to which it was subjected. Ramírez (2019)Ramírez, E.A. 2019. Efecto de consorcios PGPR sobre el desarrollo de plantas de Plukenetia volubilis y Moringa oleifera hasta fase vegetativa en comparación a fertilización convencional y orgánica en campo. Trabajo de grado para optar por el título de microbiólogo industrial. Universidad de Santander, facultad de ciencias exactas, naturales y agropecuarias. Bucaramanga, Santander, Colombia. 100 p. indicated that storage time of moringa seeds may influence on low germination percentage, even after the inoculation with mycorrhizal fungi. Vital et al. (2018)Vital, V.I., Quiñones, A.E., Hernández, M.L. & Rincón, E.G. 2018. Viabilidad de esporas de hongos micorrízicos arbusculares y semillas de girasol para el establecimiento de la simbiosis micorrízica. Biotecnología y Sustentabilidad, 3(2): 15-25, ISSN: 2448-7562. pointed out that, when applying AMF to sunflower seeds (Helianthus annuus, Asteraceae family), the germination of these seeds depended on their genotype and storage time. Knopf et al. (2016)Knopf, E., Blaschke, H., Munch, C., Murage, A., Kirika, P & Osaka, S. 2016. Impacts of soil on Mycorrizal fungi: growth responses of Moringa spp. Plants sampled from Lake Victoria Basin. Journal of Biological Sciences, 16(1-2): 12-21, ISSN: 1812-5719. evaluated the use of mycorrhizal fungi in Moringa spp. and they found that there were low percentages of germination in five days (62.5 %, 33 %), as well as in 8 and 10 days (58 %), depending on the type of soil.
Figure 6 shows that treatment 10 surpassed (p<0.001) the rest, except for treatment 8 and the fertilized control, which has the same letters.
Total germination index provides a measure of germination time relative to germination capacity. This index affected this germination capacity and does not provide information about the distribution of germination events over time (González-Zertuche and Orozco-Segovia 1996González-Zertuche, L. & Orozco-Segovia, A. 1996. Métodos de análisis de datos en la germinación de semillas, un ejemplo: Manfreda brachystachya. Boletín de la Sociedad Botánica de México, 58: 15-30, ISSN: 0366-2128. https://doi.org/10.17129/botsci.1484.), as does the phase germination index (Islam et al. 2012Islam, S., Mia, A.B., Hossain, J., Ahmed, J., Uddin, S.J., Haider, I. & Khan, M.A. 2012. Priming on embryo emergence and seedling vigor of small fruited bitter gourd (Momordica charantia L.) under suboptimal temperature. Agricultural and Food Sciences, 2: 1-10, ISSN: 0975-9107.). However, it serves for having a general confirmation about how the germination capacity of the seeds behaves depending on the total germination time.
In this variable, it was observed that treatment 10 surpassed most of the treatments, although it presented statistical similarity with treatment 8 and the fertilized control. The presence of the EcoMic® biofertilizer in this treatment influenced, as well as other variables, on the germination capacity of Moringa oleifera seeds. It is known that the inoculation of plants with effective AMF species caused a marked increase in the 17 processes of nutrient absorption and translocation, whether by interception, mass flow or diffusion (Bennett and Cahill Jr 2016Bennett, J.A. & Cahill Jr, J.F. 2016. Fungal effects on plant–plant interactions contribute to grassland plant abundances: evidence from the field. Journal of Ecology, 104(3): 755–764, ISSN: 1365-2745. https://doi.org/10.1111/1365-2745.12558.). In a study by Murali et al. (2023)Murali, M., Raj., A.J. & Wani, A.M. 2023. Effect of Seed Treatment with Bio Fertilizers on Germination Plant Height and Total Biomass of Annual Moringa (Moringa oleifera L.). Current Journal of Applied Science and Technology, 42 (34): 15-22, ISSN: 2457-1024. https://doi.org/10.9734/CJAST/2023/v42i344229., it was recorded that the application of AMF in M. oleifera, for three consecutive years, had a greater effect on germination, compared to the inoculation of rhizospheric bacteria in the same period.
The presence of growth regulators in the composition of VIUSID® AGRO is another factor that must have had an important value in this variable. Catalysis (2018)CATALYSIS. 2018. VIUSID® Agro, promotor del crecimiento. Available at: http://www.catalysisagrovete.com Consulted: December 14, 2023 stated that the Ascophyllum nodosum algae, present in the formulation of this biostimulant, also contributes to growth inducers to the formulation. This alga contains gibberellins and cytokinins, especially zeatin, which is highly biologically active, and both stimulate germination (Sandoval et al. 2018Sandoval-Rangel, A., Tapia, A., Cabrera-De la Fuente, M., González, J.A. & Benavides-Mendoza, A. 2018. Edad, beneficio y ácido giberélico afectan la germinación y producción de planta de chile piquín. Revista Mexicana de Ciencias Agrícolas, 9(20): 4199-4209, ISSN: 2007-9230. https://doi.org/10.29312/remexca.v0i20.990. and Borjas-Ventura et al. 2020Borjas-Ventura, R., Julca-Otiniano, A. & Alvarado-Huamán, L. 2020. Las fitohormonas, una pieza clave en el desarrollo de la agricultura. Journal of the Selva Andina Biosphere, 8(2): 150-164, ISSN: 2308-3859. http://doi.org/10.36610/j.sab.2020.080200150.).
Although there are no references on the effect of TOMATICID on this variable, as it is one of the components of the treatment in which EcoMic® (ST) + VIUSID® AGRO (ST) + TOMATICID (ST) was inoculated, it is inferred that it did not present a negative interaction with the rest of the bioproducts, despite the fact that no significant effect on the seed was demonstrated.
Figure 7 shows that at five DAS, treatment 10, as well as 9, were superior (p<0.01) to treatments 4, 6, 7 and 8. However, it showed letters equal to the fertilized control, and to the treatments 3 and absolute control. At 10 DAS, treatments 10, 6 and 8 showed superiority (p<0.05) with respect to the absolute control, fertilized control, treatment 5 and 7, although they shared the same letters with treatments 3, 4 and 9. At 15 DAS, treatment 10 decreased its values and was lower (p<0.01) than absolute control and fertilized control and shared the same letters with the rest. At 20 DAS, treatment 10 was superior (p<0.05) to the others.
The index of phase germination provides a measure of germination time in relation to germination capacity and is sensitive to changes in germination capacity (González-Zertuche and Orozco-Segovia 1996González-Zertuche, L. & Orozco-Segovia, A. 1996. Métodos de análisis de datos en la germinación de semillas, un ejemplo: Manfreda brachystachya. Boletín de la Sociedad Botánica de México, 58: 15-30, ISSN: 0366-2128. https://doi.org/10.17129/botsci.1484.). This variable, in general, increased as days passed, which coincided with the reports of Mehta et al. (2014)Mehta, D., Kanwar, H., Thakur, A., Thakur, S. & Thakur, K. 2014. Standardization of seed hydro-priming duration in bitter gourd, Momordica charantia L. International Journal of Bio-resource and Stress Management, 5(1): 98 – 101, ISSN: 0976-4038.. However, from 15 DAS, there was a decrease in all treatments, except for the one in which EcoMic® was applied at sowing and VIUSID® AGRO at five DAS.
Considering that the index of phase germination is more sensitive to changes in germination capacity, it can be deduced that there was more intense germinative acceleration for treatments 10, 6 and 8, at 10 DAS. However, at 15 DAS, the absolute control showed letters equal to treatments 2, 4 and 5, and higher than treatments 10, 9, 8, 7, 6 and 3. This indicates that the bioproducts that induced germinative acceleration at 10 DAS did not exert a superior effect on the subsequent phase. In general, all treatments, except EcoMic® (ST) + VIUSID® AGRO (five DAS), decreased in their values after 15 DAS, indicating that there was a normal bell-shaped distribution pattern, which agrees with the results of Barraza et al. (2016)Barraza F.A., Benavides O.B. & Torres, F.M. 2016. Calidad fisiológica y energía de germinación de semillas de balsamina (Momordica charantia L.). Revista de Ciencias Agrícolas, 33(1): 43-52, ISSN: 2256-2273. http://dx.doi.org/10.22267/rcia.163301.5. with higher values at 10 DAS in most treatments.
The application of EcoMic® (ST) + VIUSID® AGRO (five DAS) was superior to the rest of the treatments at 20 DAS and showed a higher index than that at 15 DAS. The above could be explained by the gibberellin content in VIUSID® AGRO, which can break seed dormancy and frequently replace the need for environmental stimuli, such as light and temperature. These phytohormones are important during the initial and final phases of germination (Weitbrecht et al. 2011Weitbrecht, K., Muller, K. & Leubner-Metzger, G. 2011. First off the mark: early seed germination. Journal of Experimental Botany, 62(19): 3289-3309, ISSN: 1460-2431. https://doi.org/10.1093/lxb/err030.).
VIUSID® AGRO has a molecular activation process, which allows it to accelerate and facilitate the process of enzymatic and metabolic reactions (Gavica and Gómez 2019Gavica, B.E. & Gómez, A.S. 2019. Efecto de diferentes dosis de VIUSID ®agro aplicadas durante cuatro etapas de crecimiento y desarrollo del cultivo de frijol (Phaseolus vulgaris L.). Proyecto especial de graduación presentado como requisito parcial para optar al título de Ingeniero Agrónomo. Escuela Agrícola Panamericana, Zamorano, Honduras. 22 p.). Regarding the effect of EcoMic®, it is known the ability of AMF to exude compounds that stimulate microbial activity in the ecological niche. Consequently, they all have influence on the germination process, since breaking seed dormancy favors the entire process (Rivera et al. 2011Rivera, R., Fernandez, F., Fernandez, K., Ruiz L., Sánchez, C. & Riera, M. 2011. Advances in the management of effective arbuscular mycorrhizas symbiosis in tropical ecosystems. In Chantal Hamel and Christian Plenchette (eds.) Mycorrhizas in Crop Production (pp. 151-196). Binghamton, NY: Haworth Press.).
Germination speed index (figure 8) showed that the treatment in which EcoMic® was applied at sowing and VIUSID® AGRO at five DAS was superior (p<0.0001) to the rest of inoculated treatments, including absolute control and fertilized control. The latter was superior to the absolute control and treatments 3, 4, 5, 6 and 7, in addition to sharing letters equal to 8 and 9.
The treatment in which EcoMic® was applied at sowing and VIUSID® AGRO (five DDS) was the one that had superior effect on germination speed of M. oleifera seeds.
The concept of germination speed index is important because it is related to seed vigor, considering the number that germinate and the time required to achieve it (Meot-Duros and Magné 2008Meot-Duros, L. & Magné, C. 2008. Effect of salinity and chemical factors on seed germination in the halophyte Crithmum maritimum. Plant and Soil, 313(1-2): 83-87, ISSN: 1573-5036.). In summary, this index expresses the speed in number of seeds germinated per day (Espindola et al. 2018Espindola, Y., Romero, L., Ruiz, R. & Luna, C. 2018. Influencia de las condiciones de incubación sobre la germinación de semillas de diferentes individuos de Pterogyne nitens. Quebracho-Revista de Ciencias Forestales, 26(1): 5-17, ISSN: 1851-3026.). According to Venter (2000)Van de Venter, A. 2000. Seed vigor testing. Journal of New Seeds, 2(4): 51-58, ISSN: 1522-9025. https://doi.org/10.1300/j153v02n04_06., under field (nursery) conditions, rapid germination is obviously an advantage for seedling establishment. Germination speed is, therefore, an expression of vigor. High vigor seeds germinate faster than low vigor seeds under any conditions. The influence of seed storage conditions on the germination speed of M. oleifera is also known (Silva et al. 2012Silva, P., Andrade, L.A., Venia, C.S., Fabricante, J.R. & Silva, M. 2012. Comportamiento germinativo de sementes de Moringa oleifera Lam diferentes ambientes y tiempos de almacenamiento. Agropecuaria Científica no Semiárido, 8: 1-6, ISSN: 1808-6845.).
In the variable that is discussed, it can be inferred that functionally the seeds were affected in terms of the speed with which the germination process occurred, according to the treatments. Among the bioproducts that were applied, the combination (in a fractional way) of EcoMic® and VIUSID® AGRO in treatment 10 markedly influenced, not only germination speed, but also the uniformity of seed vigor, which allowed that the latter could be expressed through a higher percentage of germination and at a higher speed compared to the other treatments. This could constitute an advantage for the establishment of seedlings in the nursery, since the seeds would germinate faster with the application of these bioproducts at different times. Peña et al. (2015)Peña, C.K., Rodríguez, F.J.C. & Meléndrez, G.J.F. 2015. Efecto de un promotor del crecimiento activado molecularmente sobre la germinación y la producción de frijol (Phaseolus vulgaris L.). Infociencia, 19 (3): 1-12, ISSN: 1029-5186. determined the effect of VIUSID® AGRO on the germination of beans (Phaseolus vulgaris L., family: Fabaceae), as well as on the growth of seedlings under in vitro conditions. These authors concluded that immersion of bean seeds for three hours in a 0.02% VIUSID® AGRO solution favors germination speed and seedling development.
The results of this variable with the simple inoculation of EcoMic® contradict those found by Laínez (2021)Laínez, P.E. 2021. Efecto de dos bioestimulantes en la producción de mudas de melón (Cucumis melo). Trabajo de Integración Curricular para la obtención del título de Ingeniera Agrónoma. Universidad Estatal de Santa Elena, Ecuador. 46 p., who observed an increase in this variable compared to control, when inoculating AMF (different species) in Cucumis melo seeds (Cucurbitaceae family). It is possible that AMF do not have the same effect on the seeds of different plant species because they have different morphological, germination and dormancy characteristics. There is also the possibility that mycorrhizae cause a coating effect on seeds, which delays the breakdown of the testa by other soil microorganisms (Ballina et al. 2017Ballina, H.S., Ruiz-Sánchez, E., Ambriz, E. & Alvarado, C.J. 2017. Efecto de la luz y micorrizas en la germinación de semillas de árboles de selvas secas. Madera y Bosques, 23(3): 29-37, ISSN: 2448-7597. https://doi.org/10.21829/myb.20117.2331531.).
The application of TOMATICID, despite having a positive influence on germination percentage when combined with the other bioproducts, did not have a superior effect on the speed of germination of the seeds. This result decreases the importance of said bioproduct for stimulating germination in moringa.
It is concluded that the combination of EcoMic® (ST) and VIUSID® AGRO (five DAS), as well as the mixture of EcoMic® + VIUSID® AGRO + TOMATICID (ST) and EcoMic® (ST) + TOMATICID (ST) accelerated partial germination at 10 DAS regarding the rest of treatments. The combination of EcoMic® (ST) and VIUSID® AGRO (five DAS) significantly influenced the speed of germination and uniformity of seed vigor, which could constitute an advantage for the establishment of seedlings in the nursery. Results indicate that the effect of the bioproducts on the germination capacity of seeds was in line with the effect on their vigor and uniformity.
It is recommended to carry out tests to evaluate germination and initial development of seedlings in the nursery, with the application of the studied bioproducts and the combinations that had better effect in the present study.