scholarly journals Effect of Phosphorus Fertilization on Growth and Flowering of Scaevola aemula R. Br. `New Wonder'

HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1728-1731 ◽  
Author(s):  
Donglin Zhang ◽  
Renae E. Moran ◽  
Lois B. Stack

Scaevola aemula R.Br. (fanflower), an ornamental plant native to Australia, produces stunted growth when fertilized with high concentrations of P. To determine optimum P concentration, rooted cuttings were transplanted into 15 cm standard pots and grown with a water soluble fertilizer, where P concentrations were 0, 14.5, 29.0, 43.5, 58.0, 72.5, 87.0 mg·L-1 and all plants received 200 mg·L-1 N and 166 mg·L-1 K. Shoot growth and flowering data were taken every 21 days until the experiment was terminated after 84 days. Shoot length, number and dry weight, and leaf size were reduced significantly at P concentrations higher than 14.5 mg·L-1 with severe reduction at P levels higher than 43.5 mg·L-1. Number of flowers per plant was not affected by P concentrations in the range of 0 to 43.5 mg·L-1, but decreased significantly at P levels higher than 43.5 mg·L-1. Medium pH decreased with increase in P rate due to the acidic nature of the P fertilizer. When P was applied in every irrigation, the optimum concentration was 14.5 mg·L-1 or less. P greater than 43.5 mg·L-1 was detrimental to vegetative growth and flowering, possibly due to above optimum P or to medium acidification.

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 426-430 ◽  
Author(s):  
Ricardo González-Ponce ◽  
Esther G. López-de-Sá ◽  
César Plaza

Struvite (MgNH4PO4·6H2O) production is widely studied as a way to remove phosphorus (P) from wastewater and generate a potentially marketable P fertilizer, but its effects on crops have yet to be researched more thoroughly. This study was conducted to evaluate struvite recovered by the Spanish Research Council (CSIC) pilot process (STR) as a source of P for lettuce (Lactuca sativa L.) by comparing its effectiveness with that of single superphosphate (SUP), a common P fertilizer derived from phosphate rock. In a greenhouse pot experiment, a P-deficient loamy sand soil was amended with either SUP or STR at P rates of 0, 4, 8, 12, 16, and 20 mg·kg−1. Nitrogen and potassium were uniformly supplied to all treatments. The response of lettuce head fresh weight and P uptake to P rate exhibited statistically significant quadratic relationships for both SUP and STR. With respect to SUP, STR was significantly more effective in increasing lettuce yield and P uptake, probably because of the larger amount of magnesium (Mg) incorporated with this material and a synergistic effect on P uptake. This work supports previous findings based on other test crops in suggesting that STR can be a P source attractive to the fertilizer market with additional agronomic and environmental benefits such as providing available Mg and nitrogen, helping attenuate consumption of phosphate rock, and reducing release of P by discharge of treated wastewaters to surface and groundwater systems.


HortScience ◽  
1994 ◽  
Vol 29 (8) ◽  
pp. 858-864 ◽  
Author(s):  
John M. Dole ◽  
Janet C. Cole ◽  
Sharon L. von Broembsen

`Gutbier V-14 Glory' poinsettias (Euphorbia pulcherrima Willd. Ex. Klotzsch) grown with ebb-and-flow irrigation used the least amount of water and produced the least runoff, and plants grown with capillary mats used the greatest amount of water and produced the most runoff, compared to microtube and hand-watering systems. The maximum amount of water retained by the pots and media was greatest for the microtube and ebb-and-flow systems and became progressively lower for the hand-watering and capillary mat systems. The media and leachate electrical conductivity from plants grown with subirrigation systems was higher than those grown with top irrigation. For the two top-irrigation systems (microtube and hand-watering), plants grown with 250 mg N/liter from a 20N-4.4P-16.6K water-soluble fertilizer had greater leaf, stem, and total dry weights than those grown with 175 mg N/liter. The two subirrigation systems (ebb-and-flow and capillary mat) produced plants that were taller and had greater leaf, stem, and total dry weights when grown with 175 than with 250 mg N/liter. The higher fertilizer concentration led to increased N, P, Fe, and Mn concentration in the foliage. Nitrogen concentration was higher in top-irrigated plants than in subirrigated plants. The ebb-and-flow system produced the greatest total dry weight per liter of water applied and per liter of runoff; capillary mat watering was the least efficient in regard to water applied and runoff.


HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 475-480 ◽  
Author(s):  
Kathryn M. Santos ◽  
Paul R. Fisher ◽  
Thomas Yeager ◽  
Eric H. Simonne ◽  
Hannah S. Carter ◽  
...  

The objective was to quantify the effect of the timing of macronutrient applications on nutrient uptake, growth, and development of Petunia ×hybrida Hort. Vilm.-Andr. ‘Supertunia Royal Velvet’ during vegetative propagation. Starting with unrooted cuttings (Day 0), fertigation was applied continuously at three time intervals (Day 0 to 7, Day 8 to 14, or Day 15 to 21) using either a “complete” (C) water-soluble fertilizer containing (in mg·L−1) 75 NO3-N, 25 NH4-N, 12 phosphorus (P), 83 potassium (K), 20 calcium (Ca), 10 magnesium (Mg), 1.4 sulfur (S), 2 iron (Fe), 1 manganese (Mn), 1 zinc (Zn), 0.5 copper (Cu), 0.5 boron (B), and 0.2 molybdenum (Mo) or a micronutrient fertilizer (M) containing (in mg·L−1) 1.4 S, 2 Fe, 1 Mn, 1 Zn, 0.5 Cu, 0.5 B, and 0.2 Mo in a complete factorial arrangement. With constant fertigation using the C fertilizer, plant dry weight (DW) doubled from Day 0 (sticking of unrooted cuttings) to Day 7 (0.020 g to 0.047 g), root emergence was observed by Day 4, and by Day 7, the average length of primary roots was 2.6 cm. During any week that the M fertilizer was substituted for the C fertilizer, tissue N–P–K concentrations decreased compared with plants receiving the C fertilizer. For example, plants receiving the M fertilizer between Day 0 and 7 had 20% lower tissue-N concentration at Day 7 compared with those receiving the C fertilizer. Although both shoot DW and leaf count increased once macronutrient fertilization was resumed after Day 7, final shoot DW and leaf count were lower than plants receiving C fertilizer from Day 0 to 21. Time to first root emergence was unaffected by fertigation. Constant application of C resulted in a higher shoot-to-root ratio at Day 21 than all other treatments. Results emphasize the importance of early fertigation on petunia, a fast-rooting species, to maintain tissue nutrient levels within recommended ranges.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11463
Author(s):  
Heba I. Mohamed ◽  
Adel A. El-Sayed ◽  
Mostafa M. Rady ◽  
Gianluca Caruso ◽  
Agnieszka Sekara ◽  
...  

Many agricultural regions in arid and semiarid climate zone need to deal with increased soil salinity. Legumes are classified as salt-sensitive crops. A field experiment was performed to examine the application of phosphorus (P) fertilizer source and rate on growth, chlorophylls and carotenoid content, DNA and RNA content and ion accumulation in common bean (Phaseolus vulgaris L.) cultivated under salinity stress. An experimental design was split-plot with three replicates. The main plots included two P sources, namely single superphosphate (SP) and urea phosphate (UP). The sub-plots covered four P rates, i.e., 0.0, 17.5, 35.0, and 52.5 kg P ha–1. All applied P fertilization rates, in both forms, increased plant height, leaf area, dry weight of shoots and roots per plant, and total dry weight (TDW) in t ha−1. The highest accumulation of N, P, K+, Mg2+, Mn2+, Zn2+, and Cu2+ was determined in the shoot and root of common bean, while 35 kg of P per ha−1 was used compared to the other levels of P fertilizer. The highest P rate (52.5 kg ha−1) resulted in a significant reduction in Na+ in shoot and root of common bean. The response curve of TDW (t ha–1) to different rates of P (kg ha–1) proved that the quadratic model fit better than the linear model for both P sources. Under SP, the expected TDW was 1.675 t ha–1 if P was applied at 51.5 kg ha–1, while under UP, the maximum expected TDW was 1.875 t ha–1 if P was supplied at 42.5 kg ha–1. In conclusion, the 35.0 kg P ha–1 could be considered the best effective P level imposed. The application of P fertilizer as urea phosphate is generally more effective than single superphosphate in enhancing plant growth and alleviating common bean plants against salinity stress.


2003 ◽  
Vol 33 (11) ◽  
pp. 2089-2096 ◽  
Author(s):  
K R Brown ◽  
P J Courtin

In southern coastal British Columbia, red alder (Alnus rubra Bong.) is recommended for reforestation on some low-elevation, fertile, and moist sites (e.g., alluvial sites). Correlative data indicate that P deficiencies limit the growth of alder in low-pH soils; deficiencies of P and other elements may also develop in the presence of an alder stand. Because alder may be grown in repeated rotations on alluvial sites, we sought to determine whether elemental deficiencies were likely in soils from mature stands. We examined the effects of P additions (as triple super phosphate) and liming (as dolomitic limestone) on potted red alder seedlings grown in soils from mature alluvial alder stands. Four soils were "low-pH" (mean = 4.5) and two were "high-pH" (mean = 5.5); all were classified as very rich. Growth of unfertilized seedlings was greatest in the soil with the highest soil Bray-P levels. Growth rates increased with P supply, but the response decreased with increasing Bray-P and was less in the high-pH soils. Liming increased soil pH and uptake of Mg, but did not increase growth. Phosphorus additions increased growth mainly by increasing P uptake, leaf size, and biomass allocation to branches. Photosynthetic rates were highest in the intermediate P treatment, but instantaneous water use efficiency increased with P rate. Phosphorus deficiencies may limit the growth of alder seedlings in alluvial soils previously containing mature alder stands.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1092d-1092
Author(s):  
T.L. Prince ◽  
H.K. Tayama ◽  
T.A. Prince ◽  
N.R. Bhat ◽  
S.A. Carver

Controlled-release fertilizers (CRF), Nutricote 14N–6.2P-11.6K or Osmocote 14N-6.2P-11.6K, at the recommended rate (1×) and at half that rate (0.5×) plus 200 mg/l N of Peter's 20N-4.4P-16.6K water soluble fertilizer at every irrigation were applied to potted chrysanthemums cv. `Bright Golden Anne' and `Torch'. Production and postproduction quality was evaluated. CRF applications (1×) resulted in reductions of plant height (-10%), plant diameter (-17%), leaf area (-35%), and leaf dry weight (-47%), but did not affect number of flowers compared to plants receiving only water soluble fertilizer. Application of water soluble fertilizer with CRF (0.5×) increased foliar nutrient levels above water soluble fertilizer application alone, or above either CRF (1×). CRF applications (1×) resulted in improved floral longevity (up to +8 days) and flower color rating (up to +54%), and less foliar senescence (up to -45%) than the water soluble fertilizer application alone, or either of the CRFS (0.5×) used with water soluble fertilizer.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 453B-453 ◽  
Author(s):  
K.M. Kelley ◽  
J.A. Biernbaum

Eight species of edible flowers were grown in 12.5-cm (1.5-L) square containers during the months of November through May, in a root medium suitable for organic certification or a standard peat and perlite mixture with preplant fertilizer. Plants were fertilized with 200 mL of either a water-soluble fertilizer (19–1.8–19) at 300 ppm N, fish emulsion (5–0.4–0.8), or a certified organic, commercially available soluble fertilizer (6–2.6–5), each at 300 or 600 ppm N applied every 2 weeks. Shoot fresh and dry weights were measured and percent dry weight was calculated. The fresh weights for all species were highest for plants fertilized with the organic fertilizers. For all but one species the organic fertilizer treatments had the same or higher dry weights than the inorganic control. The percent dry weights for all species were the same or higher for the inorganic control treatment. The effect of the organic fertilizer rate on the dry weight was species-dependent. The highest flower production generally occurred with 300 ppm N. Flower size was measured for Viola tricolor and Viola ×. wittrockiana species. For both species flower size was smallest for plants fertilized with the 600 ppm certified organic fertilizer. Root media pH and EC were tested at 6-week intervals throughout the experiment. In general, the pH increased from the first to the second sampling date, but only increased or decreased slightly for later dates, and there was little effect of fertilizer type. Root media EC decreased initially with minimal change later.


HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2047-2051 ◽  
Author(s):  
Carrie L. Whitcher ◽  
Matthew W. Kent ◽  
David Wm. Reed

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.


HortScience ◽  
2011 ◽  
Vol 46 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
Chad T. Miller ◽  
Neil S. Mattson ◽  
William B. Miller

Oxalis regnellii, the shamrock plant, and O. triangularis are niche ornamental greenhouse crops produced and marketed primarily for their foliage; thus, it is imperative to produce the fullest, most colorful, and blemish-free plants as possible. An experiment was conducted using O. regnellii, comparing two irrigation methods, overhead (drip) irrigation versus subirrigation, in addition to varying 20N–2.2P–16.6K fertilizer concentrations, 50, 100, 200, 300, and 500 mg·L−1 nitrogen (N). Overhead irrigation produced larger plants with increased root mass as compared with subirrigation. Low or high fertilizer concentration (50 mg·L−1 N and 500 mg·L−1 N, respectively) led to reductions in the fresh and dry weight of overhead-irrigated plants compared with intermediate fertilizer rates. At the highest fertilizer treatment, plant height was decreased. Chlorophyll index (based on SPAD readings) increased linearly and quadratically for subirrigated and overhead-irrigated plants, respectively. A second study analyzed the effects of seven different fertilizer formulations on growth of O. regnellii and O. triangularis. The fertilizers used in this study were Jack's LX All Purpose (21N–2.2P–16.6K), Peter's Professional (20N–8.8P–16.6K), Jacks Poinsettia FeED Ca-Mg (15N–1.7P–12.5K), Jack's Petunia FeED Mg (20N–1.3P–15.7K), Peter's Professional Peat-Lite Dark Weather Feed (15N–0P–12.5K), Peter's Excel Cal-Mag (15N–2.2P–12.5K), and the slow-release fertilizer Osmocote® (14N–4.2P–11.6K). Growth of both species was significantly reduced by fertilizers that contained little or no phosphorus (P). Current water-soluble fertilizer recommendations of 21N–2.2P–16.6K or slow-release granule fertilizer of 14N–4.2P–11.6K (Osmocote®) produced acceptable, marketable plants, whereas the best O. regnellii and O. triangularis plants were produced using 15N–2.2P–12.5K and 20N–1.3P–15.7K formulations, likely as a result of the additional calcium (Ca), magnesium (Mg), and iron (Fe) in the mixtures.


1997 ◽  
Vol 12 (2) ◽  
pp. 33-40 ◽  
Author(s):  
R. F. Walker ◽  
L. M. Kane

Abstract Ectomycorrhizal inoculation with basidiospores of Pisolithus tinctorius and fertilization with two controlled release nutrient formulations, High N 24-4-7 and Sierra 16-6-10 Plus Minors, were evaluated for their effects on containerized Jeffrey pine (Pinus jeffreyi) seedlings. Noninoculated and nonfertilized seedlings and a water soluble fertilizer treatment using Peters 20-10-20 provided for comparisons of mycorrhizal and nutrient amendment effects on growth and mineral nutrition. At 6 months, inoculated seedlings had greater root dry weight while fertilization increased shoot dimensions and weight, with the response to controlled release nutrients exceeding that to water soluble fertilizer. After 12 months, inoculation increased mycorrhizal formation, and inoculated seedlings had greater shoot volume as well as root volume, dry weight, and total length. Controlled release fertilization also promoted greater shoot growth than water soluble nutrients at the final measurement, while root system development was comparable overall among fertilized seedlings regardless of nutrient formulation. Foliar analysis revealed that concentrations of most macro- and micronutrients were sufficient for adequate seedling nutrition in all treatments. However, inoculated seedlings exhibited greater uptake of P, Ca, Mg, S, Fe, Mn, and Zn. Fertilization generally increased foliar concentrations of all of the above elements except Mg and Fe, but also increased N uptake. Overall, these results suggest that inoculation with P. tinctorius and controlled release fertilization with High N 24-4-7 and Sierra 16-6-10 facilitate production of Jeffrey pine container stock suitable for outplanting on harsh sites. West. J. Appl. For. 12(2):33-40.


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