Increased Fertilizer Levels Do Not Prevent Abscisic Acid–Induced Chlorosis in Pansy

Abscisic acid (ABA) is a plant hormone involved in regulating stomatal responses to environmental stress. By inducing stomatal closure, applications of exogenous ABA can reduce plant water use and delay the onset of drought stress when plants are not watered. However, ABA can also cause unwanted side effects, including chlorosis. Pansy (Viola ×wittrockiana) has been shown to be particularly susceptible to ABA-induced chlorosis. The objective of this study was to determine if fertilization rate affects the severity of ABA-induced chlorosis in this species. ‘Delta Premium Pure Yellow’ pansy seedlings were fertilized with controlled-release fertilizer incorporated at rates from 0 to 8 g·L−1 of substrate. When plants had reached a salable size, half the plants were sprayed with a solution containing 1 g·L−1 ABA, whereas the other plants were sprayed with water. Leaf chlorophyll content was monitored for 2 weeks following ABA application. Leaf chlorophyll content increased greatly as fertilizer rate increased from 0 to 2 g·L−1, with little increase in leaf chlorophyll at even higher fertilizer rates. ABA induced chlorosis, irrespective of the fertilizer rate. Plant dry weight was lowest when no controlled-release fertilizer was incorporated, but similar in all fertilized treatments. ABA treatment reduced shoot dry weight by ≈24%, regardless of fertilization rate. This may be due to ABA-induced stomatal closure, which limits carbon dioxide (CO2) diffusion into the leaves. We conclude that ABA sprays induce chlorosis, regardless of which fertilizer rate is used. However, because leaf chlorophyll concentration increases with increasing fertilizer rates, higher fertilizer rates can mask ABA-induced chlorosis.

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Influence of Light Intensity on Optimum Fertilization Rate in Five Species of Tropical Ornamental Plants

HortTechnology ◽

10.21273/horttech.12.2.226 ◽

2002 ◽

Vol 12 (2) ◽

pp. 226-229 ◽

Cited By ~ 2

Author(s):

Timothy K. Broschat

Keyword(s):

Light Intensity ◽

Ornamental Plants ◽

Dry Weight ◽

Fertilization Rate ◽

Fertilizer Rate ◽

Shoot Dry Weight ◽

Light Intensities ◽

Palm Species ◽

Species Optimum ◽

Fertilizer Rates

Five species of tropical ornamental plants—artillery fern (Pilea serpyllacea), pleomele (Dracaena reflexa), fishtail palm (Caryota mitis), areca palm (Dypsis lutescens), and sunshine palm (Veitchia mcdanielsii)—were grown in containers under full sun, 55% shade, or 73% shade. They were fertilized every 6 months with Osmocote Plus 15-9-12 (15N-4P-10K) at rates of 3, 6, 12, 18, 24, 30, and 36 g/pot (0.1, 0.2, 0.4, 0.6, 0.8, 1.1, and 1.3 oz/pot). For pleomele and the three palm species, optimum shoot dry weights and color ratings were similar among the three light intensities tested. However, artillery fern grown in full sun required fertilizer rates at least 50% higher for optimum shoot dry weight and color than under 55% or 73% shade. Light intensit × fertilizer rate interactions were highly significant for pilea and fishtail palm color and dry weight and sunshine palm and pleomele color.

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Antitranspirational Efficacy and Longevity of Abscisic Acid and a Synthetic Abscisic Acid Analog in Pansies (Viola ×wittrockiana)

HortScience ◽

10.21273/hortsci.49.6.779 ◽

2014 ◽

Vol 49 (6) ◽

pp. 779-784 ◽

Cited By ~ 5

Author(s):

Geoffrey M. Weaver ◽

Marc W. van Iersel

Keyword(s):

Abscisic Acid ◽

Product Quality ◽

Chlorophyll Content ◽

Stomatal Closure ◽

Net Photosynthesis ◽

Dependent Manner ◽

Leaf Chlorophyll Content ◽

Rate Dependent ◽

Leaf Chlorophyll ◽

Phytotoxic Effect

Physiological antitranspirants can reduce financial risks to growers by temporarily preventing drought stress, improving product quality, and extending the shelf life of ornamental bedding plants. Exogenous abscisic acid (ABA) is an effective antitranspirant that induces stomatal closure in a rate-dependent manner, reducing transpirational water loss in many species. However, it may also cause chlorosis, which reduces product quality. Synthetic ABA analogs have similar effects on stomatal conductance (gS) but are not known to induce chlorosis. We studied the effects of ABA and its analog 8′ acetylene ABA methyl-ester (PBI 429) on gS and net photosynthesis (Pn) in pansies (Viola ×wittrockiana), compared the efficacy and longevity of each compound, and quantified the resulting chlorosis. Plants were treated with spray solutions of ABA (0 to 2000 mg·L−1) and PBI 429 (0 to 200 mg·L−1) and irrigated daily. Gas exchange and leaf chlorophyll measurements were made twice weekly for 2 weeks. Additional measurements were taken once or twice weekly through 47 days. Abscisic acid reduced leaf chlorophyll content and Pn in a rate-dependent manner for 14 days after application but reduced gS for only 11 days, whereas PBI 429 reduced Pn and gS similarly for 7 days and did not reduce leaf chlorophyll content. Reductions in gS and Pn were greatest on the first day after treatment for both compounds. Our results demonstrate that ABA is more effective than PBI 429 at 100 and 200 mg·L−1, but also causes chlorosis, whereas PBI 429 is an effective antitranspirant without this phytotoxic effect.

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(46) Response of Container-grown Cotoneaster dammeri to Rates of Dibbled and Pre-incorporated Controlled-release Fertilizer in Three Different Media

HortScience ◽

10.21273/hortsci.41.4.1054d ◽

2006 ◽

Vol 41 (4) ◽

pp. 1054D-1055

Author(s):

C. Chong ◽

P. Purvis ◽

G. Lumis ◽

M.Z. Alam ◽

E. Roesler

Keyword(s):

Controlled Release ◽

Dry Weight ◽

Pine Bark ◽

Controlled Release Fertilizer ◽

Root Dry Weight ◽

Shoot Dry Weight ◽

Positive Correlations ◽

Fertilizer Rates

Plug-rooted liners of cotoneaster (Cotoneaster dammeri C.K. Schneid. `Coral Beauty') were grown in 6-L nursery containers filled with three different media: 73 pine bark: 22 peat: 5 pea gravel (Medium 1); 60 pine bark: 25 peat: 15 compost (Medium 2); and 50 pine bark: 50 compost (Medium 3). Plants were fertilized with Polyon (Nutryon) 17–5–12 (17N–2P–5K) 6-month controlled-release fertilizer at various rates (0, 2.5, 4.5, 6.5, and 8.5 kg·m-3 incorporated or dibbled (placed under the liner at potting). Shoot dry weight of cotoneaster increased with increasing fertilizer rates in all three media, and was consistently higher with dibble (calculated maximum ranges, 269-362 g/plant at 6.1–7.5 kg·m-3) than with pre-incorporated (127-263 g/plant at 6.4-8.5 kg·m-3) fertilizer. Trends for root dry weight were similar with dibbled fertilizer but nonsignificant with incorporation, while those for shoot: root ratio were reversed to those for shoot dry weight. Positive correlations were observed between foliar contents of N, P, and K and shoot dry weight from both dibbled and incorporated treatments, as well as root dry weight from dibbled treatments. With incorporation, however, only foliar K was correlated with root dry weight.

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Balancing Act: Effects of Fertilizer and Uniconazole on Growth of Herbaceous Perennials

HortScience ◽

10.21273/hortsci.39.4.824d ◽

2004 ◽

Vol 39 (4) ◽

pp. 824D-824 ◽

Cited By ~ 1

Author(s):

Holly L. Scoggins* ◽

Joyce G. Latimer

Keyword(s):

Controlled Release ◽

Foliar Spray ◽

Dry Weight ◽

Spray Application ◽

Artemisia Vulgaris ◽

Fertilizer Rate ◽

Height Control ◽

Herbaceous Perennials ◽

Main Effects ◽

Fertilizer Rates

Increasing fertilizer levels may reduce production time but can lead to excessive growth of herbaceous perennials, requiring the application of plant growth regulators (PGRs). This study investigated the effects of ascending fertilizer rates in conjunction with two rates of uniconazole and a control. Rooted liners of Artemisia arborescens L. `Powis Castle', Artemisia vulgaris L. `Oriental Limelight, Astilbe chinensis (Maxim.) Franch. `Pumila', Filipendula rubra (Hill) Robinson `Venusta' and Perovskia atriplicifolia Benth. were potted with controlled-release fertilizer (15N-3.9P-10K) incorporated at 2.4, 4.72, and 7.11 kg·m-3. A single foliar spray application of uniconazole was applied two weeks after transplanting at a volume of 210 mL·m-3 and two rates from 15 to 60 mg·L-1 plus a control (species-dependent). Plant height and width were measured at 2,4,6, and 8 weeks after treatment (WAT). No interactions between fertilizer rate and uniconazole were observed. Main effects varied by species. The application of uniconazole controlled height and width of Artemisia `Oriental Limelight' and Astilbe for the duration of the experiment. Height, width, and dry weight of Artemisia `Oriental Limelight' increased with ascending fertilizer rates while Astilbe was not affected. Growth of Filipendula and Artemisia `Powis Castle' was unresponsive to uniconazole, though dry weight was reduced for both at the lowest fertilizer rate. Uniconazole provided height control of Perovskia, but the effect did not persist beyond 6 WAT. Ascending fertilizer rates increased Perovskia dry weight but not height.

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504 PB 242 EFFECTS OF IRRIGATION METHOD AND CONTROLLED-RELEASE FERTILIZER RATE ON LEACHATE AND GROWTH PARAMETERS OF CHRYSANTHEMUM

HortScience ◽

10.21273/hortsci.29.5.503f ◽

1994 ◽

Vol 29 (5) ◽

pp. 503f-503

Author(s):

Thomas B. Bruning ◽

Michael H. Chaplin ◽

Henry G. Taber

Keyword(s):

Controlled Release ◽

Water Contamination ◽

Growth Parameters ◽

Dry Weight ◽

The United States ◽

Ground Water Contamination ◽

Fertilizer Rate ◽

Irrigation Treatments ◽

Greenhouse Growers ◽

Liquid Fertilization

Ground water contamination resulting from continuous liquid fertilization technologies is a serious problem facing greenhouse growers in the United States. Rooted Dendranthema grandiflora Tzvelev. cultivar 'Iridon' cuttings were transplanted into 11 cm pots filled with a 50% peatmoss and 50% perlite (v/v) media containing 0.10, 0.21, 0.42, or 0.84 g N from a controlled release 12-10-17 plus minors fertilizer deposited directly below the transplanted cutting. Pots were assigned to a top-water or subirrigation treatment. Subirrigation reduced the nitrate leachate concentration by as much as 250 ppm as compared with top-watering. Fertilizer N rate linearly decreased plant height in both of the irrigation treatments. Final dry weight of the shoot peaked at the 0.21 g N rate in both the irrigation treatments.

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Use of Species-specific Controlled-release Fertilizer Rates to Manage Growth and Quality of Container Nursery Crops

HortTechnology ◽

10.21273/horttech.25.3.370 ◽

2015 ◽

Vol 25 (3) ◽

pp. 370-379 ◽

Cited By ~ 1

Author(s):

Mary Jane Clark ◽

Youbin Zheng

Keyword(s):

Controlled Release ◽

Growth Index ◽

Dry Weight ◽

Temperate Climate ◽

Controlled Release Fertilizer ◽

Shoot Dry Weight ◽

Application Rates ◽

Nursery Crops ◽

Species Specific

The objective of this study was to determine the optimal controlled-release fertilizer (CRF) application rates or ranges for the production of five 2-gal nursery crops. Plants were evaluated following fertilization with 19N–2.6P–10.8K plus minors, 8–9 month CRF incorporated at 0.15, 0.45, 0.75, 1.05, 1.35, and 1.65 kg·m−3 nitrogen (N). The five crops tested were bigleaf hydrangea (Hydrangea macrophylla), ‘Green Velvet’ boxwood (Buxus ×), ‘Magic Carpet’ spirea (Spiraea japonica), ‘Palace Purple’ coral bells (Heuchera micrantha), and rose of sharon (Hibiscus syriacus). Most plant growth characteristics (i.e., growth index, plant height, leaf area, and shoot dry weight) were greater in high vs. low CRF treatments at the final harvest. Low CRF rates negatively impacted overall appearance and marketability. The species-specific CRF range recommendations were 1.05 to 1.35 kg·m−3 N for rose of sharon, 0.75 to 1.05 kg·m−3 N for ‘Magic Carpet’ spirea, and 0.75 to 1.35 kg·m−3 N for bigleaf hydrangea and ‘Green Velvet’ boxwood, whereas the recommended CRF rate for ‘Palace Purple’ coral bells was 0.75 kg·m−3 N. Overall, species-specific CRF application rates can be used to manage growth and quality of containerized nursery crops during production in a temperate climate.

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Growth of Bedding Plants in Substrates Amended with Compost and Fertilized with Three Different Release Rates of a Controlled-release Fertilizer Product

HortTechnology ◽

10.21273/horttech.14.4.0474 ◽

2004 ◽

Vol 14 (4) ◽

pp. 474-478 ◽

Cited By ~ 2

Author(s):

Kimberly K. Moore

Keyword(s):

Controlled Release ◽

Dry Weight ◽

Application Rate ◽

Release Rates ◽

Controlled Release Fertilizer ◽

Bedding Plants ◽

Shoot Dry Weight ◽

Standard Application ◽

Impatiens Wallerana

Growth of `Aladdin Peach Morn' petunia (Petunia × hybrida) and `Accent White' impatiens (Impatiens wallerana) was compared in substrates containing 0%, 30%, 60%, or 100% compost made from biosolids and yard trimmings and fertilized with Nutricote Total 13-13-13 (13N-5.7P-10.8K) Types 70, 100, and 140 incorporated at rates of 0.5x, 1x, 2x, or 3x (x = standard application rate for a medium-feeding crop). Petunia shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x increased as the percentage of compost in the substrate increased from 0% to 60% and then decreased, while shoot dry weight of plants fertilized with Type 70 incorporated at 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 30% and then decreased. Impatiens shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x and 1x also increased as the percentage of compost increased from 0% to 30% and then decreased, while shoot dry weight of plants fertilized at 2x and 3x decreased as the percentage of compost increased from 0% to 100%. Both petunia and impatiens shoot dry weight of plants fertilized with Type 100 and Type 140 incorporated at 0.5x, 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 60% and then decreased.

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Effects of Light, Soil Moisture, and Nutrition on Greenhouse Propagation of Twinflower

HortTechnology ◽

10.21273/horttech03685-17 ◽

2017 ◽

Vol 27 (6) ◽

pp. 782-788

Author(s):

Jonathan Foster ◽

Stephanie Burnett ◽

Lois Stack

Keyword(s):

Soil Moisture ◽

Survival Rate ◽

Controlled Release ◽

Root Development ◽

Dry Weight ◽

Water Volume ◽

Native Plant ◽

Controlled Release Fertilizer ◽

Partial Shade ◽

The Impact

Twinflower (Linnaea borealis) is an understory subshrub native to northern regions of North America, Europe, and Asia. Some growers report that this native plant is difficult to propagate. Although twinflower prefers partial shade and grows in areas with naturally variable moisture, there has been no greenhouse propagation work testing the impact of light or soil moisture conditions on root development of this plant or whether fertilizer impacts root development or root:shoot ratios during propagation. The goal of the first experiment was to propagate twinflower under a variety of daily light integrals (DLI)—27.6, 14.4, or 5.8 mol·m−2·d−1—and soil volumetric water content values (θ = volume of water ÷ volume of soil) 0.30, 0.35, 0.40, and 0.45 L·L−1, both parameters aimed at reproducing a range of natural conditions. The largest roots were grown at DLIs of 5.8 and 14.4 mol·m−2·d−1 and θ values of 0.30 and 0.35 L·L−1. In the second experiment, twinflower plants were grown in substrates with 0, 2.1, or 5.0 g·L−1 of incorporated controlled-release fertilizer (14N–6.1P–11.6K). Root and shoot dry weight increased at both treatment rates. The relative percentages of nitrogen, phosphorus, and potassium, and the total concentrations of manganese in parts per million, increased in foliage, as well. In both experiments, the source of cuttings impacted results. In the first experiment, cuttings taken from the source that was in the most light were least likely to survive (26% survival rate) compared with cuttings taken from stock plants growing in partial shade (65% or 82% survival rates, by site). In the second experiment, cuttings taken from source plants that were most intensively managed for removal of weeds and competing plants had the highest survival rate and the greatest shoot and root dry weight. We recommend propagating twinflower with moderate rates of fertility (i.e., 2.1 g·L−1 of incorporated controlled-release fertilizer) under some shade (5.8–14.4 DLI) and a moderate θ (0.30–0.35 L·L−1).

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122 Minimizing Fertilizer Input for Nitrate Management and Optimum Growth of Ilex verticillata L.

HortScience ◽

10.21273/hortsci.34.3.462e ◽

1999 ◽

Vol 34 (3) ◽

pp. 462E-462

Author(s):

T.L. Schultz ◽

U.K. Schuch

Keyword(s):

Controlled Release ◽

Nitrate Leaching ◽

Block Design ◽

Dry Weight ◽

Research Station ◽

Optimum Growth ◽

Liquid Fertilizer ◽

Controlled Release Fertilizer ◽

Randomized Block Design ◽

Container Nurseries

Nitrate nitrogen is becoming a major pollutant in much of our nation's water supply. High levels of nitrate runoff are commonly found to occur from intense agricultural areas such as container nurseries. The objective of this study was to investigate combinations of liquid fertilizer (LF) plus controlled-release fertilizer (CRF) that would both minimize nitrate runoff and provide nutrient levels for optimum growth of Ilex verticillata L. The experiment was established in 1998 at the Iowa State Univ. Horticulture Research Station, Ames. Six fertilizer treatments were arranged in a randomized block design with eight replications. Treatment combinations of liquid fertilizer (LF) and controlled-release fertilizer (CRF) were [LF (mg/L)/CRF (g)]: 90/0, 90/8.5, 90/17, 180/0, 180/8.5, 180/17 (Peter's Excel 21-5-20 and Osmocote 18-6-12, 9-month release, respectively). Analysis of nitrate leaching showed that in 12 out of 16 weeks, the 180 mg/L LF treatments resulted in twice the amount of nitrate leached compared to the 90 mg/L LF. In 3 out of 16 weeks, treatments containing 0 g CRF leached significantly less nitrate than those containing 17 g CRF. None of the treatments produced a difference in total dry weight or caliper of Ilex verticlillata L. This data suggests that plant growth remains similar over a range of fertilizer input and higher rates of applied LF result in higher nitrate leaching.

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INPUTS OPTIMIZATION IN THE SEEDLINGS PRODUCTION OF Corymbia citriodora E Eucalyptus dunnii

FLORESTA ◽

10.5380/rf.v52i1.78100 ◽

2022 ◽

Vol 52 (1) ◽

pp. 103

Author(s):

Claudia Costella ◽

Maristela Machado Araujo ◽

Álavro Luís Pasquetti Berghetti ◽

Suelen Carpenedo Aimi ◽

Marllos Santos de Lima ◽

...

Keyword(s):

Controlled Release ◽

Dry Weight ◽

Growth Potential ◽

Morphological Attributes ◽

Controlled Release Fertilizer ◽

Physiological Variables ◽

Eucalyptus Dunnii ◽

Chlorophyll A And B ◽

Corymbia Citriodora

Corymbia citriodora and Eucalyptus dunnii are species of relevant importance due to the quality of the wood and growth potential in Southern Brazil. Therefore, we aimed to identify containers and doses of controlled-release fertilizer capable of enhancing the morphophysiological quality and growth of these species in the nursery, aiming for the proper management of these inputs. The seedlings were produced in two volumes of containers (50 e 110 cm³), filled with Sphagnum peat-based substrate, mixed with different doses of controlled-release fertilizer (CRF) NPK 15-09-12 (0, 3, 6, 9 e 12 g L-1 of substrates). In addition, the morphological (height, stem diameter, leaf area, dry weight of shoot, root, and total) and physiological (chlorophyll a and b index and quantum yield of the photosystem II) attributes were evaluated. The morphological attributes proved to be suitable indicators of the quality of C. citriodora and E. dunnii seedlings, allowing to recommend the container of 50 cm³ and the doses of 9.0 g L-1 of controlled-release fertilizer for both species. At the same time, the physiological variables evaluated were not responsive to the effect of the treatments.

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