Puakenikeni (Fagraea berteroana) is a popular flower in lei making in Hawaii, especially during graduation season and mothers day, which coincide with the flowering period. Most of the propagation is done via air layers, to promote early flowering. Propagation via rooted cuttings has been reported in the literature, however, there are is no information in regards to best practice, and it is a common question asked to the the University of Hawaii at Manoa Cooperative Extension Services. This trial used different powder rooting hormones to compare their effectiveness in propagating semi hardwood cuttings of puakenikeni. Cuttings were dipped in the rooting hormone, and the lower 2 inches of each cutting was inserted in a mix of 50% perlite and 50% vermiculite and placed in a mist bench for 2 months. Three treatments were compared (no rooting hormone, and 0.1%, 0.3% and 0.8% IBA). A total of 80 cutings were used, or 20 cuttings per treatment. After two months the control treatment with no rooting hormone had only 10% rooting. The 0.1% IBA and 0.3% IBA had 30% and 10% rooted cuttings, respectively. The 0.8% IBA treatment had 85% rooting success. Results from this trial indicate that a rooting hormone with 0.8% IBA should be used when rooting semi hardwood cuttings of puakenkeni (Fagraea berteroana). Future trials may be performed to compare other concentrations and types of rooting hormones (powder, liquid and gel), in order to achieve higher rooting percentage rates.
The growing demand for sustainable landscapes and eco-friendly practices has significantly influenced consumer interest in native plant species. Agastache spp. is a xeric species naturally acclimated to the Rocky Mountain region and is valued for its ornamental flowering and exceptional landscape resilience, particularly in arid environments. However, one challenge is the limited availability of saleable plants due to challenges during asexual propagation, in particular, successful adventitious rooting of cuttings. Therefore, a study was conducted to evaluate the impact of different indole-3-butyric acid (IBA) rooting hormone concentrations on root initiation and development of Agastache ‘Coronado Red’. A total of 72 uniform stem cuttings were collected and 18 stems were treated with one of four experimental treatments that included, control (water), 1000, 3000, and 8000 ppm IBA concentrations. Cuttings were stuck in 72-cell trays and placed on a propagation misting bench, using a randomized complete block design. Destructive data collection occurred on a bi-weekly basis, with three collections. The experiment was repeated over the course of two production seasons. Two weeks after sticking, while callus initiation was present on cuttings for all treatments, an increase in both the number of primary roots and root length was observed as the concentration of IBA increased. For example, the number of primary roots was greatest for cuttings provided the IBA concentration of 8000 ppm (16) compared to the control (0.2) and IBA concentrations of 1000 (3.4) and 3000 ppm (6.3). Similarly, length of the longest root was 1891%, 144%, and 62% greater under the IBA concentration of 8000 ppm compared to the control and IBA concentrations of 1000 and 3000 ppm, respectively. Stem length and the number of nodes were similar for all treatments. These results indicate that higher IBA concentrations promote root initiation and growth as early as two weeks after sticking for Agastache ‘Coronado Red’. While results from the present study indicate that an IBA concentration of 8000 ppm is optimal for early establishment of Agastache ‘Coronado Red’ cuttings, future research is required to determine propagation strategies for other cultivars.
Plant growth and development depends on essential macronutrients such as nitrogen (N), phosphorus (P), and potassium (K), and deficiencies in these nutrients result in significant physiological and morphological changes. Leaf biochemical and biophysical properties influence light absorption and reflectance across various wavelengths, providing insights into canopy health. Advancements in high-throughput (HT) digital phenotyping technologies, including high-resolution scanning and multispectral imaging, have improved plant health assessment and monitoring. The TraitFinder, a digital phenotyping system developed by Phenospex, is equipped with two PlantEye-600 multispectral 3D laser scanners that generate three-dimensional plant models while capturing multispectral data. The system directs light in green (G), blue (B), red (R), and near-infrared (NIR) wavelengths onto the plant canopy and captures the reflected signals, which are then used to compute vegetation indices for plant health evaluation. This study utilized the TraitFinder system to determine reference values for vegetation indices associated with healthy plants and those deficient in N, P, and K. Four ornamental species—coleus (Solenostemon scutellarioides), marigold (Tagetes patula), petunia (Petunia × hybrida), and celosia (Celosia plumosa)—were evaluated over time. The experiment followed a randomized complete block design with eight replications and four nutrient treatments: a complete Hoagland’s solution and three modified versions, each lacking one macronutrient (N, P, or K). Morphological traits, such as biomass, showed reduced plant growth under nutrient-deficient conditions. Spectral data revealed common trends in nutrient-deficient plants, including decreased Green Leaf Index (GLI) and Normalized Difference Vegetation Index (NDVI) and increased Normalized Pigment Chlorophyll Ratio Index (NPCI) and Plant Senescence Reflectance Index (PSRI) compared to controls. In healthy plants, GLI ranged from 0.2 to 0.35, NDVI from 0.4 to 0.75, NPCI from 0.10 to 0.45, and PSRI from 0.07 to 0.25. However, species-specific responses to nutrient deficiencies were also observed. This study highlights the distinct morphological and physiological responses of ornamental species to macronutrient deficiencies and demonstrates the effectiveness of digital phenotyping using the TraitFinder system for tracking plant health over time. The findings emphasize the potential of HT digital phenotyping which could enhance ornamental crop management.
High fertilizer costs and environmental impacts are growing concerns in modern agriculture, and the floriculture industry is increasingly adopting the use of biostimulants to enhance plant growth, stress tolerance, and nutrient use efficiency. Despite their potential, the effectiveness and specificity of many biostimulants remain poorly understood. This study evaluated the growth-promoting effects of Lalrise Vita, a commercial biostimulant containing the phosphate solubilizing bacteria Bacillus velezensis. Lalrise Vita's impact on plant growth and health was evaluated using Tagetes patula ‘Durango Yellow’ (French marigolds) and Viola × wittrockiana ‘Clear Yellow’ (pansies). The first experiment evaluated how fertilizer at increasing concentrations affected the plant responses to the biostimulant. A water-soluble fertilizer delivered 50, 150, 300, or 600 mg·L–1 nitrogen (N) from 15N–2.2P–12.5K–2.9Ca–1.2Mg applied once weekly with 100 mL of solution per pot. Lalrise Vita was applied once at transplant at 0.25 g per plant as a substrate drench of 100 mL of solution per pot, with untreated plants as controls for both experiments. The second experiment focused on phosphorus (P) fertilization, with plants receiving increasing P concentrations of 2.5, 5, 10, or 20 mg·L–1 from KH₂PO₄ once a week along with the fertilizer. Plants were fertilized weekly with 100 mL of solution delivering 200 mg·L–1 N from 15N–0P–12.5K–2.9Ca–1.2Mg. Plants were scanned using the Trait Finder (Phenospex), and digital biomass, normalized pigment chlorophyll ratio index, plant senescence reflectance index, and HUE were used to identify differences in plant growth and health. In marigolds, Lalrise Vita improved digital biomass and plant health across all fertilizer rates compared to untreated plants. The greatest differences were observed at lower fertilizer concentrations (50 and 150 mg·L–1 N). Significant improvements were observed in pansies at 50 mg·L–1 N, including increased biomass and improved health indicators. Marigold plants treated with Lalrise Vita at 5 and 10 mg·L–1 P had greater growth, although spectral variables indicated greener foliage at higher P rates in untreated plants. There were no significant differences in pansies between treated and untreated plants, suggesting that Lalrise Vita-treated plants receiving 2.5 mg·L–1 P performed comparably to those receiving 20 mg·L–1 P without Lalrise Vita. Excessive fertilizer (300 and 600 mg·L–1 N) reduced Lalrise Vita’s benefits, as phosphate-solubilizing bacteria are less effective when P is not limiting. However, Lalrise Vita can be used to grow quality crops with reduced fertilizer applications.
Easter lilies (Lilium longiflorum) cultivated in the greenhouse industry are often treated with plant growth regulators (PGRs) to control their height by reducing stem length. A greenhouse study was conducted to examine the effects of uniconazole “Sumagic” on the growth of a new cultivar of Easter lilies ‘White Spring’. Treatments consisted of five bulb sizes based on circumference (12/14, 14/16, 16/18, 18/20, 20/22 cm) and uniconazole rates of 0, 2.5, and 5.0 mg•liter-1 with eight replications. Data collection consisted of stem height measured weekly, days until anthesis, number of flowers, and phytotoxicity rating. The results of the study showed a relationship between the uniconazole treatments and plant height, control plants had a greater average height (57.8 cm) than the bulbs soaked in 2.5 and 5.0 mg•liter-1 uniconazole, (33.5 cm) and (23.8 cm), respectively. Plant heights were also influenced by bulb size as they increased in height with increase in bulb circumference. The average number of days until anthesis increased with smaller bulb circumference, as anthesis was delayed. Days until anthesis were also affected by the uniconazole treatments, the bulbs treated with 2.5 and 5.0 mg•liter-1 solutions took approximately 6 and 8 days longer, respectively. Phototoxicity effects displayed as chlorosis on leaf tips and margins occurred in both the 2.5 and 5.0 mg•liter-1 solutions with symptoms more prominent in larger bulb sizes.
Soil pH shapes rhizosphere microbial structure and diversity, influencing nutrient cycling, plant growth, and ecosystem health. However, the effects of pH on the microbiome in greenhouse-grown ornamental plants in peat-based soilless substrates are less well understood. This study examined the impact of substrate pH and plant species on rhizosphere bacterial communities to see how the interaction of these factors influenced microbial diversity. A two-factor experiment with substrate pH (4.5, 5.5, 6.2, and 7) and plant species (geranium, marigold, petunia, and tomato) was conducted in a greenhouse with six replicates per treatment (n=6) in a random complete block design. Substrate-only controls were included at each pH level to evaluate plant species influence on the bacterial community. The peat-based substrate pH was adjusted with dolomitic limestone. Plants were fertilized at each irrigation with 100 µg·g-1 N from 15-5-15-Ca-Mg fertilizer. After eight weeks of growth, the ornamental plants were fully flowering, and the tomato plants were beginning to bud. At that time, plant morphology and vegetative indices were evaluated by 3D image analysis, vegetive tissue and substrate leachate were evaluated for nutrient content, and rhizosphere samples were collected to evaluate bacterial composition and diversity by 16S amplicon sequencing. Plant species differentially modified the substrate pH from the starting levels. Geranium and marigold acidified the substrate, tomato tended to increase substrate pH, and petunia maintained pH close to the initial values. Shannon diversity indices indicated that bacterial diversity varied across the pH and plant species treatments. At pH 4.5, geranium, marigold, and tomato plants reduced the diversity relative to the no plant control. Geranium and tomato plants also reduced diversity at pH 5.5, while petunia plants at 5.5 exhibited the highest diversity across all plant species (p=0.0159). Beta diversity analysis identified pH as the dominant factor explaining 53.7% in Bray-Curtis dissimilarity and 68.5% in the weighted UniFrac distance metrics (both p
