scholarly journals Fertilization of Young `Hamlin' Orange Trees with Controlled-release Fertilizer

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 774A-774
Author(s):  
J.J. Ferguson ◽  
F.S. Davies
Keyword(s):  
Controlled Release ◽  
Tree Height ◽  
Leaf Nitrogen ◽  
N Fertilizer ◽  
Water Soluble ◽  
Slight Reduction ◽  
Leaf Nitrogen Content ◽  
Controlled Release Fertilizer ◽  
Trunk Diameter ◽  
Orange Trees

Young `Hamlin' orange trees [Citrus sinensis (L.) Osbeck] were fertilized six times/year with water-soluble N fertilizer at recommended rates (0.20, 0.34, and 0.38 kg N/tree per year) and with controlled-release fertilizer one time/year [Osmocote, IDBU, and a 44.5% urea-N fertilizer coated with a sulfonated ethylene-propylene-diene polymer (Sherritt, Inc.)] at 0.04, 0.06, and 0.08 kg N/tree per year for years 1, 2, and 3, respectively. There were no differences in trunk diameter, tree height, or tree rating among treatments in any year, although there was a slight reduction in tree rating for some trees with biuret symptoms in the Sherritt treatment in year 2. Leaf nitrogen content was acceptable for all treatments in all 3 years, except for the Osmocote treatment in year 2, which had low to deficient levels. Levels of other nutrients were all within acceptable ranges, except for low potassium levels for the Osmocote in year 2. There were no significant differences in yields of young trees in year 3, the first bearing year. Given its 44.5% N analysis, the total amount of Sherritt controlled-release fertilizer applied to young citrus trees was 4% that of the standard, water-soluble fertilizer and from 39% to 45% that of the two other controlled-release fertilizers in years 1, 2, and 3.

Improvement of leaf nitrogen content inference in Valencia-orange trees applying spectral analysis algorithms in UAV mounted-sensor images

2019 ◽  
Vol 83 ◽  
pp. 101907 ◽  
Author(s):  
Lucas Prado Osco ◽  
Ana Paula Marques Ramos ◽  
Érika Akemi Saito Moriya ◽  
Maurício de Souza ◽  
José Marcato Junior ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Nitrogen Content ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Content ◽  
Valencia Orange ◽  
Orange Trees

scholarly journals 503 PB 219 RECYCLING SOLUTIONS AND METHOD OF FERTILIZATION INFLUENCE GROWTH OF HYBRID GERANIUM

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 503e-503
Author(s):  
Patricia R. Knight ◽  
D. Joseph Eakes ◽  
Charles H. Gilliam ◽  
Harry G. Ponder
Keyword(s):  
Controlled Release ◽  
Water Soluble ◽  
Plant Quality ◽  
Pine Bark ◽  
Peat Moss ◽  
Production Medium ◽  
Controlled Release Fertilizer ◽  
Soluble Fertilizer ◽  
Receiving Water

Seed geranium (Pelargonium × hortorum Bailey `Scarlet Elite') were grown in subirrigation troughs in 10-cm pots from 25 June to 3 August 1993. Production medium was a 1 pine bark:3 peat moss:1 perlite (v:v:v) mixture. Plants were irrigated using fresh or recycled solutions and fertilized using Peter's Geranium Special 15N-6.5P-12.5K or Osmocote 14N-6.1P-11.6K. Controlled release fertilizer produced greater shoot dry weights and foliar color ratings than plants receiving water soluble fertilizer. Plants receiving a controlled release fertilizer had lower shoot N concentrations than plants receiving water soluble fertilizer. Recycled irrigation solutions reduced plant quality regardless of method of fertilization.

scholarly journals Controlled-release Fertilizer during Cutting Propagation Affects Growth and Tissue Nutrient Concentrations of Rooted Cuttings of Annual Bedding Plants

HortScience ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 152-159 ◽  
Author(s):  
Christopher J. Currey ◽  
Roberto G. Lopez
Keyword(s):  
Controlled Release ◽  
Dry Mass ◽  
Water Soluble ◽  
Nutrient Concentrations ◽  
Controlled Release Fertilizer ◽  
Bedding Plants ◽  
Tissue Nutrient Concentrations ◽  
Soluble Fertilizer ◽  
Soilless Substrate ◽  
The Impact

Our objectives were to quantify the effects of controlled-release fertilizer (CRF) on the growth, morphology, and tissue nutrient concentration of annual bedding plants during propagation. Unrooted cuttings of Angelonia angustifolia ‘AngelFace White’ and ‘Sundancer Pink’, Impatiens hawkeri ‘Celebrette Apricot’ and ‘Celebrette Rose Hot’, Nemesia fruticans ‘Bluebird’ and ‘Raspberry Sachet’, Pelargonium ×hortorum ‘Savannah Red’, and Petunia ×hybrida ‘Cascadia Marshmallow Pink’ and ‘Suncatcher Yellow’ were received from a commercial propagator. Cuttings were immediately stuck individually in cells containing soilless substrate supplemented with 0, 3, 6, 12, or 24 g·L−1 CRF (Osmocote Plus 15–3.9–10 3–4 month) and placed under clear mist water or cuttings were stuck in substrate containing no CRF and fertilized with water-soluble fertilizer beginning immediately after placing cuttings into propagation. Shoot dry mass of cuttings grown in substrates containing up to 12 or 24 g·L−1 CRF increased by up to 150% for some taxa compared with unfertilized cuttings. Incorporating CRFs into propagation substrates increased the concentration of nitrogen (N), phosphorus (P), and potassium (K) in tissues by up to 103%, 42%, and 137%, respectively, compared with unfertilized cuttings. Additionally, tissue nutrient concentrations for cuttings fertilized with 6 g·L−1 CRF or greater were similar to cuttings receiving water-soluble fertilizer (WSF). When the impact of CRF on growth and nutrient concentrations are taken together, our results indicate that CRF is a fertilization application technology that holds promise for use during propagation of herbaceous stem-tip cuttings.

scholarly journals Fertigation and Growth of Young `Hamlin' Orange Trees in Florida

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 106-109 ◽  
Author(s):  
Leah E. Willis ◽  
Frederick S. Davies ◽  
D.A. Graetz
Keyword(s):  
Tree Height ◽  
Additional Treatment ◽  
Nutrient Concentrations ◽  
Fertilizer Rate ◽  
Trunk Diameter ◽  
Liquid Material ◽  
One Year ◽  
Nutrient Analyses ◽  
Orange Trees ◽  
Fertilizer Rates

One-year-old `Hamlin' orange [Citrus sinensis (L.) Osb.] trees on sour orange rootstock (C. aurantium L.) were used to compare various fertigation frequencies and rates with application of granular materials. In Expt. 1, granular fertilizer was applied five times per year or liquid fertilizer was applied five, 10, or 30 times per year at 0.23 kg N/tree per year as an 8N-3.4P-6.6K formulation. In Expt. 2, an additional treatment of granular and liquid material was applied three times per year, but fertilizer rate and formulation were the same as in Expt. 1. Experiment 3 included the same application frequencies as Expt. 1, but with two rates of N (0.11 or 0.06 kg N/tree per year). Soil samples were taken from each treatment 1, 4, and 7 days after fertilization at depths of 0-15, 16-46, and 47-76 cm for nutrient analyses. Trunk diameter, shoot growth, and tree height were similar for all treatments 8 months after planting in Expts. 1 and 2, while trees in Expt. 3 had significantly less growth at the lower rate. Soil NH4-N and NO3-N concentrations for all liquid treatments within 1 week of fertilization were highest for the five times per year treatment at the 0- to 15-cm depth, but nutrient concentrations of all liquid treatments were similar at the other depths. For most dates and depths, NH4-N and NO3-N concentrations were similar for both fertilizer rates.

scholarly journals Adaptation to Sun and Shade: a Whole-Plant Perspective

1988 ◽  
Vol 15 (2) ◽  
pp. 63 ◽  
Author(s):  
TJ Givnish
Keyword(s):  
Biotic Interactions ◽  
Tree Height ◽  
Light Response ◽  
Leaf Nitrogen ◽  
Compensation Point ◽  
Carbon Gain ◽  
Leaf Nitrogen Content ◽  
Energy Capture ◽  
Irradiance Level ◽  
Whole Plant

Whole-plant energy capture depends not only on the photosynthetic response of individual leaves, but also on their integration into an effective canopy, and on the costs of producing and maintaining their photosynthetic capacity. This paper explores adaptation to irradiance level in this context, focusing on traits whose significance would be elusive if considered in terms of their impact at the leaf level alone. I review traditional approaches used to demonstrate or suggest adaptation to irradiance level, and outline three energetic tradeoffs likely to shape such adaptation, involving the economics of gas exchange, support, and biotic interactions. Recent models using these tradeoffs to account for trends in leaf nitrogen content, stornatal conductance, phyllotaxis, and defensive allocations in sun v. shade are evaluated. A re-evaluation of the classic study of acclimation of the photosynthetic light response in Atriplex, crucial to interpreting adaptation to irradiance in many traits, shows that it does not completely support the central dogma of adaptation to sun v. shade unless the results are analysed in terms of whole-plant energy capture. Calculations for Liriodendron show that the traditional light compensation point has little meaning for net carbon gain, and that the effective compensation point is profoundly influenced by the costs of night leaf respiration, leaf construction, and the construction of associated support and root tissue. The costs of support tissue are especially important, raising the effective compensation point by 140 �mol m-2 s-1 in trees 1 m tall, and by nearly 1350 �mol m-2 s-1 in trees 30 m tall. Effective compensation points give maximum tree heights as a function of irradiance, and shade tolerance as a function of tree height; calculations of maximum permissible height in Liriodendron correspond roughly with the height of the tallest known individual. Finally, new models for the evolution of canopy width/height ratio in response to irradiance and coverage within a tree stratum, and for the evolution of mottled leaves as a defensive measure in understory herbs, are outlined.

scholarly journals Effect of Liner Container Size, Root Ball Slicing, and Season of Root Pruning in a Field Nursery on Quercus virginiana Mill. Growth and Anchorage After Transplanting

2016 ◽  
Vol 42 (4) ◽  
Author(s):  
Edward Gilman ◽  
Maria Paz ◽  
Chris Harchick
Keyword(s):  
Tree Height ◽  
Root Systems ◽  
Root Pruning ◽  
Slight Reduction ◽  
Bending Stress ◽  
Trunk Diameter ◽  
Quercus Virginiana ◽  
Nursery Stock ◽  
Field Nursery ◽  
Dormant Season

Size of liner, root ball slicing when field planting, and field root pruning season were tested with intention of optimizing posttransplant performance of field-grown nursery stock. Trees planted into a field nursery from three container sizes and either root ball sliced or not when shifted to larger containers or planting to the field nursery, and root pruned in the field nursery in either the dormant season or growing season all had the same trunk diameter (144 mm) and tree height (6.4 m) three years after transplanting into the landscape. Container size influenced root attributes—including number and orientation—and anchorage rating of field-harvested trees. Trees planted from 11 L containers required more bending stress to winch trunks evaluated 12 and 25 months after transplanting than larger containers. Percentage of root systems graded as culls was reduced from 88 to 66 by root pruning when field planting, but root pruning resulted in a slight reduction in anchorage rating. Diameter of the ten largest roots at edge of field-harvested root ball decreased with size of container planted into field soil. Root pruning season had no impact on final tree height (4.3 m) at the conclusion of field production.

scholarly journals Effects of Controlled-Release Fertilizer Placement on Nutrient Leaching and Growth of Bedding Impatiens

2015 ◽  
Vol 33 (2) ◽  
pp. 58-65
Author(s):  
G.A. Andiru ◽  
C.C. Pasian ◽  
J.M. Frantz
Keyword(s):  
Controlled Release ◽  
Tap Water ◽  
Canopy Cover ◽  
Dry Weight ◽  
Water Soluble ◽  
Controlled Release Fertilizer ◽  
Bedding Plants ◽  
Shoot Dry Weight ◽  
Application Rates ◽  
Soluble Fertilizer

Bedding impatiens plants were grown with a 16N-3.9P-10K controlled-release-fertilizer (CRF) of 5–6 or 8–9 month longevities placed at four positions in the container: top-dressed, incorporated, top-one-third, and bottom. These were compared to plants grown with a 20N-4.4P-16.6 water-soluble fertilizer (WSF) at a rate of 150 mg·L−1 nitrogen (N) (150 ppm N). All treatments received the same volume of tap water (CRF treatments) or fertilizer solution (WSF treatment), which was enough to achieve a 20 to 30% leaching fraction. Leachates were collected and measured at each irrigation and the concentrations of N, phosphorous (P), and potassium (K) were measured. Shoot dry weight (SDW) and canopy cover (CC) were also determined. Fertilizing with WSF produced plants of similar size as CRF treatments. CRF applied at the bottom of the substrate leached the highest amount of N among all treatments. Higher concentrations for most nutrients were measured in the leachates from containers treated with 5–6 month CRF during the first 20 d after planting than the next 23 to 34 days. The higher levels of nutrients in the leachates observed within two weeks after planting does not support the use of 5–6 month CRF at the application rates used in this experiment with short-cycle plants such as bedding plants in compared to use of WSF. Except for the bottom placement treatment, the use of 8–9 month CRF resulted in generally less nutrients leached than WSF.

scholarly journals Hydroponic Fertilizer Supply for Basil Using Controlled-release Fertilizer

HortScience ◽  
2020 ◽  
Vol 55 (10) ◽  
pp. 1683-1691
Author(s):  
Fernanda Trientini ◽  
Paul R. Fisher
Keyword(s):  
Controlled Release ◽  
Nutrient Release ◽  
Nutrient Content ◽  
Water Soluble ◽  
Plant Performance ◽  
Small Scale ◽  
Single Application ◽  
Fresh Weight ◽  
Controlled Release Fertilizer ◽  
Shoot Fresh Weight

Small-scale hydroponics is a growing urban horticulture trend, but nutrient solution management remains a challenge for small growers. The objective was to investigate the potential to use controlled-release fertilizer (CRF) to simplify nutrient management in small-scale hydroponic systems. Three experiments were conducted with the goal of a single fertilizer application during the crop cycle of basil (Ocimum basilicum). Nutrient release curves were quantified by adding prills to water and measuring nutrient content weekly in the solution for CRF products without plants. In all seven products tested (Osmocote Bloom 2–3M, Osmocote Plus 3–4M, E-Max Calcium Nitrate 2–3M, Agrocote MAP 3–4M, E-Max Keiserite 3–4M, E-Max K-Mag 2–3M, and Agrocote SOP 3–4M) an initial rapid release was followed by a plateau, but release rates differed between products varying from 100% (MgSO4) to 60% release [(NH4).(H2PO4)] over an 11-week evaluation period. Total nutrient content in two commercial N–P–K CRF products (3–4 months 15N–3P–10K and 2–3 months 12N–3.1P–14.9K) provided lower Ca and Mg compared with a typical hydroponic solution based on water-soluble fertilizer (WSF). A subsequent experiment evaluated plant growth response using the same two commercial CRF products (single application) or a WSF (replaced weekly) in growth chamber environment. Plants grown for 4 weeks under CRF treatments yielded less than half the shoot fresh weight of plants grown with WSF and exhibited symptoms of Ca deficiency and micronutrient toxicity (confirmed with tissue analysis). Electrical conductivity (EC) of CRF solutions increased over time indicating excess dose compared with plant uptake, reaching a maximum of 5.4 dS·m−1. Nutrient release curves from the first experiment were then used to estimate product release and create a single-application nutritional program based on a customized “Blend” developed from CRF macronutrients plus WSF micronutrients. Plants were grown hydroponically with two dosages of Blend (1X and 2X) and compared with a commercial WSF with weekly replacement of solution. Blend 2X and WSF treatments had similar shoot fresh weight (241 and 244 g/four plants, respectively) with healthy plant appearance and tissue nutrient levels generally within published survey ranges for basil. Commercial CRF products designed for soil or container production were unsuitable for hydroponics, but acceptable plant performance with the customized CRF Blend demonstrated proof-of-concept for a single CRF application.

scholarly journals Effect of Nitrogen Fertilization Rate on Aesthetic Quality of Landscape-grown Vines and Groundcovers

2014 ◽  
Vol 24 (5) ◽  
pp. 604-609 ◽  
Author(s):  
Amy L. Shober ◽  
Kimberly A. Moore ◽  
Gitta S. Hasing ◽  
Christine Wiese ◽  
Geoffrey C. Denny ◽  
...  
Keyword(s):  
Controlled Release ◽  
Fertilization Rate ◽  
N Fertilization ◽  
N Fertilizer ◽  
Aesthetic Quality ◽  
Controlled Release Fertilizer ◽  
Central Florida ◽  
West Central ◽  
Quality Response

Research supporting recommendations for fertilizer needs of landscape-grown vines and groundcovers is lacking. The objectives of our study were to (1) evaluate the quality response of selected vine and groundcover species to nitrogen (N) fertilization at five rates and (2) validate the recommended N fertilizer rates (from the initial evaluation) by monitoring quality of additional landscape-grown vine and groundcover species. Three vine species and two groundcover species were planted in west-central Florida into raised beds containing subsoil fill material in a completely randomized design. Plants were fertilized every 6 weeks with a controlled release fertilizer (20N–0P–0K–23S) at an annual N rate of 0, 2, 4, 6, or 12 lb/1000 ft2. Plant aesthetic quality (0–5 scale) was assessed every 6 weeks for 30 weeks after planting. Although quality of some species increased significantly as N rate increased, all plants supplied with at least 4 lb/1000 ft2 per year N fertilizer had acceptable quality ratings of 3 or better. Screening of three additional vines and four additional groundcovers fertilized with controlled release fertilizer (42N–0P–0K) at an annual N rate of 3, 5, or 7 lb/1000 ft2 confirmed that fertilization with 2 to 4 lb/1000 ft2 per year should be adequate to maintain acceptable vines and groundcovers grown in the landscape in west-central Florida.

scholarly journals Long-term Response of `Hamlin' Orange Trees to Controlled-release Nitrogen Fertilizers

HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 423-426 ◽  
Author(s):  
Thomas A. Obreza ◽  
Robert E. Rouse
Keyword(s):  
Controlled Release ◽  
Management Practice ◽  
N Fertilizer ◽  
Water Soluble ◽  
Soluble Solids ◽  
Nitrogen Fertilizers ◽  
Juice Quality ◽  
Citrus Production ◽  
High Yields

Controlled-release N (CRN) fertilizer is receiving interest as a possible nutrient best management practice (BMP) for Florida citrus production, but grower acceptance will be limited until cost decreases and familiarity with CRN materials increases. The objective of this study was to compare long-term citrus production resulting from N fertilizer programs containing isobutylidene diurea (IBDU) or methylene urea (MU) with a conventional water-soluble N fertilizer program to determine the magnitude of horticultural utility provided by CRN. We applied N to a newly planted `Hamlin' orange (Citrus sinensis L. Osbeck) orchard using three sources (100% ammonium nitrate (AN); a 50/50 mixture of AN/IBDU; a 60/40 mixture of AN/MU) at four rates (0.25, 0.5, 1.0, and 2.0 or 1.5 times the recommended annual rate) in factorial combination, and continued for 7 years. During this period, AN was applied 31 times vs. about 15 times for CRN-containing fertilizers. We measured fruit yield, juice quality, and total soluble solids (TSS) yield in years 4 through 7 and found that they generally were not affected by N source, especially when year-to-year variation was taken into account. In year 7, fruit and TSS yields of well-fertilized trees reached 153 and 9.2 kg/tree, respectively. Maximum 4-year cumulative fruit and TSS yields (486 and 27.6 kg/tree, respectively) occurred at an N rate of 200 kg/ha. Maximum juice quality occurred at 180 kg N/ha. We feel the CRN materials tested could be used successfully in a nutritional BMP program that would maintain high yields while potentially decreasing N loss to the environment.

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