Nutritional Studies of Christmas Bell

Eighteen-month-old seedlings of Christmas Bell (Blandfordia grandiflora Sm.) in 800-ml containers were top dressed with 8- to 9-month Osmocote controlled-release fertilizer 18N-2.6P-10K at 0, 0.625, 1.25, 2.5, 5.0, or 10 kg·m-3. Other plants were fertilized once or twice weekly with a complete liquid fertilizer supplying 100 mg N/liter based on an N : K ratio of either 1:0.6 or 1:1.5. The former ratio was the same as the Osmocote while the latter was the N : K ratio in tops of healthy wild-growing plants of B. grandiflora. The highest fresh weights occurred at the Osmocote rate of 5 kg·m-3 and with the once-weekly liquid feed of 1 N : 1.5 K ratio. Plants fertilized with low rates of Osmocote were pale green but had extensive root systems that were white and predominantly fibrous. As the rate of Osmocote was increased, plants became greener and produced smaller root systems in which fleshy storage organs were predominant over fibrous roots.

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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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Substrates and controlled-release fertilizations on the quality of eucalyptus cuttings

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v18n11p1124-1129 ◽

2014 ◽

Vol 18 (11) ◽

pp. 1124-1129 ◽

Cited By ~ 8

Author(s):

Richardson B. G. da Silva ◽

Magali R. da Silva ◽

Danilo Simões

Keyword(s):

Controlled Release ◽

Water Retention ◽

Management Strategies ◽

Eucalyptus Grandis ◽

Root Systems ◽

Eucalyptus Urophylla ◽

Controlled Release Fertilizer ◽

Coconut Fibre ◽

Proper Values

To produce cuttings with quality, the most appropriate nutritional management strategies should be sought to reduce wastage of fertilizer, while accounting for the characteristics of each substrate. This study evaluated the effect of substrates and doses of controlled-release fertilizer on the quality of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla S. T. Blake cuttings. The substrates consisted of several mixtures: vermiculite+carbonized rice chaff+coconut fibre (1:1:1); vermiculite+coconut fibre (1:1); and vermiculite+carbonized rice chaff (1:1). These mixtures were added to 2, 4, 6 and 8 kg of controlled-release fertilizer per cubic meter of substrate. The substrates that do not support root development and have lower water retention, independently of the dose of controlled-release fertilizer, reduce the quality of the root system. For substrates with proper values of water retention, such as vermiculite+coconut fibre (1:1) and vermiculite+carbonised rice chaff+coconut fibre (1:1:1), the utilization of dose 2 kg of controlled-release fertilizer to each cubic meter is enough to promote cuttings with greater quality of the root systems and proper heights and stem diameters.

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