scholarly journals Nitrogen Nutrition of New Guinea Impatiens and Spathiphyllum in a Subirrigation System

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 859A-859
Author(s):  
Matthew W. Kent ◽  
David Wm. Reed
Keyword(s):  
Nitrogen Nutrition ◽  
Chlorophyll Concentration ◽  
New Guinea ◽  
Dry Weight ◽  
Maximum Growth ◽  
Fertilization Rate ◽  
Relative Distribution ◽  
Soluble Salts ◽  
New Guinea Impatiens ◽  
Peace Lily

Greenhouse cultural methods must change rapidly to minimize runoff and to keep pace with environmental regulation aimed at protecting water resources. Two experiments were designed to investigate the effect of N fertilization rate on New Guinea impatiens (Impatiens ×hawkeri) and peace lily (Spathiphyllum Schott) in an ebb-and-flow subirrigation system. Maximum growth response for impatiens was centered around 8-mM N levels as measured by root and shoot fresh and dry weight, height, leaf number, leaf area, and chlorophyll concentration. For peace lily, growth peaked around 10 mM N. Growing medium was divided into three equal layers: top, middle, and bottom. Root distribution favored the middle and bottom layers, and the relative distribution of roots was consistent as N level increased. Soluble salts remained low in middle and bottom layers at N concentrations below 10 mM, but increased significantly for all soil layers at levels above 10 mM. The top layer contained two to five times higher soluble salt levels than in the middle or bottom layers at all N levels. Increased nitrate concentration mimicked increases in soluble salts, while pH decreased as N concentration increased for both impatiens and peace lily.

scholarly journals Nitrogen Nutrition of New Guinea Impatiens `Barbados' and Spathiphyllum `Petite' in a Subirrigation System

1996 ◽  
Vol 121 (5) ◽  
pp. 816-819 ◽  
Author(s):  
Matthew W. Kent ◽  
David Wm. Reed
Keyword(s):  
Nitrogen Nutrition ◽  
Chlorophyll Concentration ◽  
New Guinea ◽  
Dry Weight ◽  
Maximum Growth ◽  
Fertilization Rate ◽  
N Fertilization ◽  
Relative Distribution ◽  
New Guinea Impatiens ◽  
Peace Lily

Greenhouse cultural methods must minimize runoff to keep pace with environmental regulation aimed at protecting water resources. Two experiments were designed to investigate the effect of N fertilization rate on New Guinea impatiens (Impatiens ×hawkeri) and peace lily (Spathiphyllum Schott) in an ebb-and-flow subirrigation system. Maximum growth response for impatiens was centered around 8 mm N levels as measured by root and shoot fresh and dry weight, height, leaf number, leaf area, and chlorophyll concentration. For peace lily, growth peaked at about 10 mm N. Growing medium was divided into three equal layers: top, middle, and bottom. Root distribution favored the middle and bottom layers, and the relative distribution of roots was consistent as N level increased. EC remained low in middle and bottom layers at N concentrations below 10 mm, but increased significantly for all layers at levels above 10 mm. The EC for the top layer was 2 to 5 times higher than in the middle or bottom layers at all N levels. Increased nitrate concentration paralleled increased EC, while pH decreased as N concentration increased for impatiens and peace lily.

scholarly journals SOLUBLE SALTS BUILDUP AS A CAUSE OF EARLY GROWTH SUPPRESSION OF NEW GUINEA IMPATIENS

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1162g-1162
Author(s):  
Laura K. Judd ◽  
Douglas A. Cox
Keyword(s):  
Growth Medium ◽  
Growth Response ◽  
New Guinea ◽  
Dry Weight ◽  
Early Growth ◽  
Growth Suppression ◽  
Soluble Salts ◽  
Shoot Dry Weight ◽  
New Guinea Impatiens ◽  
Similar Growth

To test the effect of soluble salts on the growth of New Guinea impatiens (Impatiens platypetala), `Selenia' was grown for 70 days in a soilless medium and irrigated with solutions of 20N-4.3P-16.6K at rates of 0.5, 1.0, 1.5, or 2.0 g·liter-1. A fifth treatment was no fertilization for the first 14 days, 0.5 g·liter-1 for the next 14 days and 1.0 g·liter-1 till finish. At 14-day intervals shoot dry weight and growth medium soluble salts were measured. By 42 days after planting, differences between treatments were statistically significant with respect to dry weight. Over a 70-day period, growth was greatest with 0.5 g·liter-1. The 1.0 g·liter-1 treatment caused a similar growth response. Plants in delay treatment responded similarly to 0.5 and 1.0 g·liter-1. Higher rates, 1.5 and 2.0 g·liter-1, caused growth suppression and resulted in soluble salts buildup in the growth medium. Soluble salts levels of 1.5 dS·m-1 and above suppressed early growth. Results show that during the first 42-56 days of growth, New Guinea impatiens are sensitive to soluble salts and levels over 1.5 dS·m-1 are cause for concern.

scholarly journals RESPONSE OF NEW GUINEA IMPATIENS TO FERTILITY LEVEL IS AFFECTED BY APPLICATION FREQUENCY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 688c-688
Author(s):  
Laura K. Judd ◽  
Douglas A. Cox
Keyword(s):  
Growth Medium ◽  
Significant Interaction ◽  
New Guinea ◽  
Dry Weight ◽  
Fertility Level ◽  
Soluble Salts ◽  
Fertilizer Rate ◽  
Shoot Dry Weight ◽  
Application Frequency ◽  
New Guinea Impatiens

New Guinea impatiens (Impatiens sp. hybrids) are particularly sensitive to growth medium soluble salts level during the first four to six weeks after potting. Results of this experiment show that this response is affected by the interaction of fertilizer rate and application frequency. Solutions containing 20N-4.3P-16.6K at 0.5, 1.0, 1.5, or 2.0 g·liter-1 were applied to `Selenia' growing in 520 ml pots 4, 8, 12, or 16 times (evenly-spaced) during a 70 day experiment. A significant interaction occurred between fertilizer rate and application frequency. Shoot dry weight (DW) increased linearly with application frequency at 0.5 g·liter-1. Overall 16 applications of 0.5 g· liter-1 resulted in the most growth of all rate and frequency combinations. Maximum DW at 1.0 g·liter-1 was achieved with 12 applications and 8 applications resulted in the most DW with 1.5 and 2.0 g·liter-1. In treatments where growth was inhibited, growth medium EC exceeded 1.0 dS·m-1. EC did not exceed 0.4 dS·m-1 at any application frequency with 0.5 g·liter-1.

scholarly journals Interaction of Light Intensity and Controlledrelease Fertilization Rate on Growth and Flowering of Two New Guinea Impatiens Cultivars

2004 ◽  
Vol 14 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Wagner Vendrame ◽  
Kimberly K. Moore ◽  
Timothy K. Broschat
Keyword(s):  
Light Intensity ◽  
New Guinea ◽  
Dry Weight ◽  
Fertilization Rate ◽  
Plant Quality ◽  
Flower Number ◽  
Shoot Dry Weight ◽  
Quality Ratings ◽  
Quality Rating ◽  
New Guinea Impatiens

New guinea impatiens (Impatiens hawkeri) (NGI) `Pure Beauty Rose' (PBR) and `Paradise Orchid' (PO) were grown in full sun, 55% shade, or 73% shade and fertilized with a controlled-release fertilizer (CRF) [Nutricote Total 13-13-13 (13N-5.7P-10.8K), type 100] incorporated at rates of 2, 4, 6, 8, 12, 16, 20, 24, 28 and 32 lb/yard3 of growing media (1.2, 2.4, 3.6, 4.7, 7.1, 9.5, 11.9, 14.2, 16.6, and 19.0 kg·m-3). Plant quality rating, shoot dry weight, and flower number were measured at harvest and substrate samples were collected to analyze final substrate pH and electrical conductivity (EC). For both cultivars, light intensity and fertilization rate interactions were different for shoot dry weight and flower number, but there was no difference in plant quality rating between the light levels. Quality ratings of both PBR and PO plants increased as CRF rate increased to 12 to 16 lb/yard3 above these levels quality was not improved. Shoot dry weight of PBR plants grown in full sun increased as CRF rate increased to 28 lb/yard3 and then decreased, while shoot dry weight of plants grown with 55% and 73% shade increased as CRF rate increased to 20 and 16 lb/yard3, respectively, with no further increases. Shoot dry weight of PO plants grown in full sun and 55% shade increased as CRF rate increased to 28 and 24 lb/yard3, respectively, with no further increases, while shoot dry weight of plants grown with 73% shade increased as CRF rate increased to 24 lb/yard3 and then decreased. Flower number of PBR plants grown in full sun, 55% shade, and 73% shade increased as CRF rate increased to 24 lb/yard3 and then decreased. Flower number of PO plants grown in full sun increased as CRF rate increased to 28 lb/yard3 and then decreased, while flower number of plants grown in 55% and 73% shade increased as CRF rate increased to 24 lb/yard3 and then decreased.

scholarly journals Optimum Potassium Concentrations in Recirculating Subirrigation for Selected Greenhouse Crops

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1441-1444 ◽  
Author(s):  
Trisha Blessington Haley ◽  
David Wm. Reed
Keyword(s):  
Growth Parameters ◽  
New Guinea ◽  
Middle Layer ◽  
Maximum Growth ◽  
Bottom Layer ◽  
Growing Medium ◽  
K Fertilizer ◽  
K Concentration ◽  
New Guinea Impatiens ◽  
Recommended Level

Two experiments were conducted to investigate the effect of K fertilizer rates on growth of New Guinea impatiens (Impatiens Hawkeri Bull.), vinca (Catharanthus roseus (L.) G. Don) and petunia (Petunia ×hybrida Hort. Vilm.-Andr.) in a recirculating subirrigation system. Based on a variety of growth parameters, a broad range of K concentrations allowed maximum growth, notably 1 to 6 mM for New Guinea impatiens `Ovation Salmon Pink Swirl', 2 mm for New Guinea impatiens `Cameo' and `Illusion', 2 to 8 mm for vinca `Pacifica Apricot', and 2 to 16 mm for petunia `Trailing Wave Misty Lilac'. Thus, the lowest concentration that allowed maximum growth was 1 to 2 mm K. A third experiment compared the optimum K concentration and K balance of vinca grown with recirculating subirrigation versus top-watering. Based on a variety of growth parameters of vinca `Pacifica Red', the lowest concentration that allowed maximum growth was 2 mm K with recirculating subirrigation and 4 mm K with top-watering. The K balance demonstrated that subirrigated plants were twice as efficient in K use compared to the top-watered plants. Leachate loss was the major contributor to inefficiency in top-watered plants. Electrical conductivity (EC) of the growing medium remained below the recommended level of 1.2 dS·m-1 in both irrigation methods at K concentrations of 16 mm and below in the bottom layer and 8 mm and below in the middle layer. In the top layer of the growing medium, EC was above the recommended level at all K concentrations tested in subirrigation at all concentrations, and in top-watering at 16 mm and above.

scholarly journals Response of Kientzler New Guinea Impatiens to Manual and Chemical Pinching

HortScience ◽  
1991 ◽  
Vol 26 (7) ◽  
pp. 856-857 ◽  
Author(s):  
Terri Woods Starman
Keyword(s):  
Plant Height ◽  
Shoot Apex ◽  
New Guinea ◽  
Dry Weight ◽  
Plant Size ◽  
Flowering Plant ◽  
Potted Plants ◽  
Delayed Flowering ◽  
New Guinea Impatiens

Manually and chemically pinched plants of 18 cultivars of Impatiens hybrids (Kientzler New Guinea impatiens) were compared to control plants to determine the effect of shoot apex removal on flowering, plant size, and branching characteristics. Either pinching treatment delayed flowering by ≈3 days compared with nonpinched controls. Pinching had no effect on plant height or fresh or dry weight. Plant diameter and form changes due to pinching depended on cultivar. Total branch count was increased by chemical but not manual pinching although both pinching methods affected mode of branching. The 18 cultivars of Kientzler New Guinea impatiens were best grown as 0.4-liter potted plants without the aid of pinching.

scholarly journals Effects of Fertilizer Concentration and Minimum-leach Drip Irrigation on the Growth of New Guinea Impatiens

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 683-688 ◽  
Author(s):  
Harvey J. Lang ◽  
Timothy R. Pannkuk
Keyword(s):  
Drip Irrigation ◽  
Root Zone ◽  
Irrigation System ◽  
Irrigation Treatment ◽  
Growth Index ◽  
New Guinea ◽  
Maximum Growth ◽  
Dry Mass ◽  
Leaching Fraction ◽  
New Guinea Impatiens

New Guinea impatiens `Barbados' (Impatiens ×hawkeri) were fertilized with solutions containing N at 6, 12, or 18 mmol·L-1 delivered from a drip irrigation system with either minimum leaching or standard leaching (0.3 to 0.4 leaching fraction). Irrigation was monitored and controlled by computers using microtensiometers placed in representative pots of each treatment. In two separate experiments, growth index, fresh mass, and dry mass were dependent upon both fertilizer concentration and irrigation treatment. Maximum growth overall was achieved at 12 mmol·L-1 N regardless of irrigation treatment; however, standard-leached plants receiving N at both 6 and 18 mmol·L-1 produced larger plants than did similarly fertilized minimum-leached plants. Leaf scorch, spotting, or marginal necrosis did not occur in any of the treatments. Leaf N, P, and K concentrations were highest in plants treated with N at 18 mmol·L-1, but Ca, Mg, and several micronutrients were highest in plants at 6 mmol·L-1 N. At the end of the cropping period for both experiments, growing medium electrical conductivity (EC) in the uppermost one-third layer of the pot was two to four times as high as that in the bottom two-thirds (root zone) layer. Root-zone EC ranged from 0.6 to 4.0 dS·m-1 and increased as fertilizer concentration increased. Standard leaching had little effect in reducing root-zone EC except in plants fertilized with N at 18 mmol·L-1. All plants continued to perform well and flower after 4 weeks in a simulated interior environment. Minimum-leach drip irrigation used ≈35% less solution than did standard irrigation with leaching, and eliminated N runoff.

scholarly journals Phosphorus Concentration Affects New Guinea Impatiens and Vinca in Recirculating Subirrigation

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2047-2051 ◽  
Author(s):  
Carrie L. Whitcher ◽  
Matthew W. Kent ◽  
David Wm. Reed
Keyword(s):  
Linear Models ◽  
Growth Parameters ◽  
Growth Parameter ◽  
New Guinea ◽  
Dry Weight ◽  
Water Soluble ◽  
Phosphorus Concentration ◽  
Flower Number ◽  
P Rate ◽  
New Guinea Impatiens

The objective of this study was to quantify the optimum rates of water-soluble phosphorus (P) under constant nitrogen and potassium on the growth of new guinea impatiens (Impatiens hawkeri Bull.) `Paradise Violet' and vinca Catharanthus roseus `Pacifica Red' in soilless media in a recirculating subirrigation system. The experiment was designed so that only phosphate varied between treatments while all other nutrients remained constant. The ammoniacal N to nitrate N ratio was varied to counter balance increases in phosphate. Sodium was used as a counter ion to phosphate at higher concentrations of phosphate; sodium proved to be toxic at concentrations above 6 mm. In the new guinea impatiens experiment, there was a small increase in K due to the use of dibasic K phosphate to buffer pH. All growth parameters measured (height, leaf number, flower number, and shoot fresh and dry weight) showed significant differences with increasing P rate. Depending on the growth parameter measured, quadratic–linear models revealed an optimum P rate of 0.1 to 0.96 mm for new guinea impatiens `Paradise Violet' and 0.45 to 1.25 mm P for vinca `Pacifica Red'. For dry shoot weight, a common measure of optimum plant growth, the optimum P rate was 0.75 mm P for new guinea impatiens `Paradise Violet' and 0.67 mm P for vinca `Pacifica Red'. For flower number, a common measure of floral quality, the optimal P rate was 0.96 mm P for new guinea impatiens `Paradise Violet' and 1.25 mm P for vinca `Pacifica Red'. Electrical conductivity (EC) of the growing media increased significantly with increasing rate of P. At all rates, EC was significantly greater in the top layer than in the bottom and middle layers. The pH of the growing medium did not vary in relation to P concentration.

scholarly journals Effects of Heat Stress on Floral and Vegetative Development in New Guinea Impatiens

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 570f-571
Author(s):  
Kerry M. Strope ◽  
Mark S. Strefeler
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Selection Index ◽  
New Guinea ◽  
Dry Weight ◽  
Flower Number ◽  
Flower Bud ◽  
Combining Abilities ◽  
Heat Tolerant ◽  
New Guinea Impatiens

Fifty-three commercial New Guinea Impatiens cultivars (Impatiens hawkeri Bull.) from six different breeding series were tested for level of heat tolerance. Five floral (flower number, flower length, flower width, floral dry weight, and flower bud number) and five vegetative characteristics (leaf dry weight, stem dry weight, total dry weight, number of nodes, and number of branches) were evaluated with emphasis placed on continued flowering under long term heat stress. Significant differences among cultivars were found in each data category (P ≤ .0001). Flower number varied from 0 to 6, flower length varied from 10 to 51 mm, flower width varied from 10 to 47 mm, floral dry weight varied from 0 to 0.5 g, and flower bud number varied from 0 to 14. Four heat tolerant (Celebration Cherry Red, Celebration Rose, Lasting Impressions Shadow, and Paradise Moorea) and three nonheattolerant (Lasting Impressions Twilight, Danziger Blues, and Pure Beauty Prepona) cultivars were identified using a Weighted Base Selection Index. These cultivars were used as parents in a full diallel crossing block with reciprocals and selfs. One hundred seedlings from each of 49 crosses were evaluated for heat tolerance. General and specific combining abilities of the parents were evaluated as was heritability. It was found that the four heat tolerant cultivars had higher general combining abilities. Heat tolerance has low heritability and is controlled by many genes. Superior genotypes were identified (selection intensity of 0.05) and retained for further evaluation and breeding efforts.

scholarly journals New Guinea Impatiens Growth Response and Nutrient Release from Controlled-release Fertilizer in a Recirculating Subirrigation and Top-watering System

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 280-286 ◽  
Author(s):  
Daphne L. Richards ◽  
David Wm. Reed
Keyword(s):  
Controlled Release ◽  
Lower Bound ◽  
Growth Response ◽  
Growth Parameters ◽  
Dry Weight ◽  
Maximum Growth ◽  
Controlled Release Fertilizer ◽  
Shoot Dry Weight ◽  
Quadratic Response ◽  
New Guinea Impatiens

New Guinea impatiens (Impatiens hawkeri Bull.) `Illusion' were grown in a recirculating subirrigation system under various rates and placements of 14N-6.1P-11.6K (Osmocote; Scotts-Sierra, Marysville, Ohio) resin-coated, controlled-release fertilizer (CRF). Four CRF placements (incorporated, top-dressed, bottom, and dibble) were tested. Incorporated placement yielded slightly greater dry weights than the other placements. A rate experiment tested incorporating from 0.5 to 2 times the fertilizer manufacturer's recommended rate of 7.11 kg·m-3. All shoot growth parameters (height, leaf number, shoot, and root fresh and dry weight) exhibited a significant quadratic response, as exemplified by shoot dry weight, where shoot dry weight increased up to the 1.5× rate, after which shoot dry weight decreased. A quadratic response surface model revealed that the optimum rate response ranged from 1.16× rate for height to 1.47× rate for shoot dry weight. The lower bound of the 95% confidence interval (CI) would be the lowest rate at which one could expect maximum growth response. The lower bound of the 95% CI varied from 0.56× rate for height to 1.30× rate for shoot dry weight. Thus, the lowest rate that would be within the 95% CI for all growth parameters, and thus yield maximum growth response, would be the 1.30× rate. Electrical conductivity (EC) of the growing media increased significantly with increasing CRF rate. At all rates, EC was significantly greater in the top layer than in the middle and bottom layers. Only in the 1.75× and 2× rates did EC exceed the recommended EC levels in the middle and bottom layer. All rates >0.75× exceeded recommended EC in the top layer. Release characteristics and total nutrient balance of the CRF was compared in subirrigated and top-watered systems. There was no significant difference between top-watered and subirrigated treatments for the amount of K recovered in plant tops and released from prills. By day 84, in subirrigation, 46% of the K was still in the prills, 41% was recovered in the plant tops, and 22% was recovered in the medium. Similar results were obtained in the top-watering treatment, except that a lesser amount was recovered in the medium (9%) and a small amount (4%) was recovered in the leachate. The uptake of K by plants and release of K by the CRF were inversely proportional and linear with respect to time. Of the K released from the prills, 77% and 83% were recovered in the plant tops for subirrigation and top-watering, respectively, indicating very high fertilizer use efficiency.

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