Solidago canadensis L. cv. Tara and Delphinium elatum, the hybrid White River are summer flowers with great agronomic potential. The goal of this study was to establish the phenology of these species grown under greenhouse conditions, as well as to determine the correlation between climatic elements (relative humidity - RH, growing degree-days for development - GDD and soil moisture - SM) with growth variables (stem length and diameter, fresh weight FW - and dry weight - DW) in S. canadensis and D. elatum. The life cycle for S. canadensis and D. elatum ended when reaching 30% of the flower opening, the stem length reached 118.05 and 123.74 cm, at 94 and 77 days, respectively. The growth of both species showed a logistic curve pattern throughout the crop cycle; S. canadensis showed maximum values for absolute growth rate (AGR) and relative growth rate (RGR) at 77 and 42 days after transplanting (DAT), respectively; in contrast to D. elatum which occurred at 77 and 28 DAT. On the other hand, for the correlation between climatic elements and growth variables in S. canadensis, the GDD and RH were directly correlated with both FW and DW, stem diameter and length, while an inverse correlation occurred for SM. D. elatum showed a direct correlation between climatic conditions and growth variables.

Light supplementation with HPS lamps is widely used in the production of short-day cut-flowers, such as Aster sp. and Solidago canadensis; In turn, LEDs are an affordable energy-saving alternative to replace HPS lamps, but its effectiveness in Aster sp. and S. canadensis was not studied yet. Thus, the aim of this study was to evaluate the influence of HPS and LED lamps on growth, development, flowering inhibition, and profitable value of Aster sp. and S. canadensis. For this, two assays with five hours of light supplementation were conducted, each one corresponding to one species. Aster sp. varieties were: Annency, Cirina, and White; light sources: HPS or LED lamps; and light intensities: intense or diffuse. The phenological development was not affected by light sources or intensities, with all treatments effectively inhibiting premature flowering in both species. Stem length was reduced under LED lamps in A. White, while the other growth parameters were unaffected or improved in the other varieties and species. The fewer “carnival” stems (exportation market) under LED lamps had a lower income; however, LEDs resulted in higher profits due to its lower energy consumption (47.35% lower than HPS). Therefore, LED lighting effectively inhibited premature flowering in Aster sp. and S. canadensis and maintained the quality of the cut-flowers at a lower production cost.

El objetivo del estudio fue analizar cómo el uso de tutoreo influye en la obtención de flores de corte de Hypericum spp. Se empleó un diseño de bloques completos al azar con parcelas divididas, donde las parcelas principales representaron el manejo con y sin tutoreo, y las subparcelas incluyeron tres variedades de Hypericum spp. (Vulcano, Rubí y Código V71), distribuidas en cuatro bloques, con diez plantas/bloque como unidad experimental. En relación con la variable de acame de tallos, Vulcano presentó una media de 2,5 tallos por planta. El número de yemas axilares inducidas en las tres variedades no se vio afectado por el tutoreo. La estimación del IAF ubicó a V71 con el mejor índice de 0,66, sin que el uso o no de mallas tutoras tuviera influencia en esta variable. La rectitud de tallos se observó en Rubí y V71, con disposición a un crecimiento de tallos rectos, mientras que Vulcano, debido a su hábito de crecimiento, presentó diversas curvaturas en los tallos. En cuanto al número de bayas, Rubí exhibió hasta el 60 % de tallos con más de 12 bayas, indicando una calidad destacada para la comercialización. Los tallos comerciables de Rubí y V71 fueron de 140,63 y 136,13 tallos m-2, respectivamente, y demostraron su potencial de rendimiento en comparación con Vulcano. En contraste, en el caso de tallos no comerciales, la variedad V71 exhibe una mayor cantidad con un promedio de 49,25 tallos m-2. No obstante, se recomienda aplicar el tutoreo únicamente en la variedad Vulcano debido a su rendimiento más bajo. Estos resultados demuestran la relevancia de estudiar y aplicar el tutoreo de manera específica según las características de cada variedad de Hypericum spp. destinada a la exportación.

Biostimulants from Ascophyllum nodosum (L.) are effective as regulators of molecular, physiological and biochemical processes in plants. Two independent experiments were conducted using foliar application in Rosa × hybrida variety White O’Hara of two A. nodosum-based biostimulant formulations (B1: A. nodosum (10% w/v), N, P₂O₅, K, Ca, Mg, oxidizable total organic carbon (3% w/v), minor elements, and free amino acids (3.9% w/v); B2: A. nodosum (11% w/v), oxidizable total organic carbon (6.8% w/v) N (37.2% w/v), and P₂O₅ (50% w/v)). Each experiment was conducted in a Randomized Complete Block Design (RCBD) with a factorial arrangement including four treatments (0; 0.5; 1.0; and 1.5 mL L⁻¹), which were evaluated over two production cycles. Foliar chlorophyll (μmol m⁻²), stomatal conductance (mmol m⁻² s⁻¹), and leaf vapor pressure deficit were measured every two weeks, and productivity was evaluated at the end of the cycle. Statistical differences were detected in chlorophyll content for the application of B1 and B2 over two production cycles with increases of around 16–17% in chlorophyll compared to the control. Significant differences in stomatal conductance were detected during weeks 20 and 22 for all doses. The control treatment consistently exhibited lower means for the leaf vapor pressure deficit compared to B1 and B2. Biostimulants improved photosynthetic activity and carbon assimilation and also delayed leaf senescence. B1 at 1 mL L⁻¹ reduced unproductive stems from 54% to 38% compared to the control. Biostimulant treatments enhanced physiological tolerance to temperature extremes (2.2–32.6 °C). Based on the results, 1.5 mL L⁻¹ of the B1 biostimulant and 1 mL L⁻¹ of the B2 are recommended; these findings offer key insights for optimizing rose cultivation and prove that intensive floriculture can be both productive and sustainable.

The aim of this research was to characterize the phenology and phenometric variables of Gypsophila paniculata L. ‘Overtime®’ in managed field conditions, as well as to determine the correlation between abiotic factors (mean temperature, relative humidity, vapor pressure deficit, growing degree days) and phenometric variables (stem length and diameter, number of nodes, internodes, leaves and shoots and dry matter) and to calculate growth rates absolute and relative. To collect field data, a randomized complete block design with six blocks was employed, each block contained four to five plants, which served as experimental units. The crop cycle of G. paniculata was evaluated from transplanting to the senescence phase, for a total duration of 132 days after transplanting. The developmental stages of the species were characterized in detail, with the commercial harvest stage reached at 91 days after transplanting during flowering, corresponding to a cumulative growing degree of 1255.1 °C day. A sigmoid growth pattern was observed throughout the successive phenological stages, with the maximum absolute growth rate occurring between 60 - 75 days after transplanting, during this period, exogenous factors were integrated, including supplemental artificial lighting and gibberellic acid treatment, to enhance growth and induce flowering. After 75 days after transplanting, the relative growth rate declines as assimilates shift toward flowering. Among the phenometric variables, only stem length was significantly affected by temperature, relative humidity, and vapor pressure deficit, indicating that these environmental factors modulate growth dynamics throughout the crop cycle. These findings provide new insights into the growth dynamics and developmental responses of the species and contribute to the refinement of agronomic management practices under variable environmental conditions.