Historic note

Group Title: Bradenton GCREC research report - University of Florida Gulf Coast Research and Education Center ; BRA1984-7
Title: Rieger begonia production under subtropical conditions
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00065198/00001
 Material Information
Title: Rieger begonia production under subtropical conditions
Series Title: Bradenton GCREC research report
Physical Description: 5 leaves : ; 28 cm.
Language: English
Creator: Harbaugh, B. K ( Brent Kalen )
Cooper, Valerie F., 1953-
Gulf Coast Research and Education Center (Bradenton, Fla.)
Publisher: Gulf Coast Research and Education Center, IFAS, University of Florida
Place of Publication: Bradenton FL
Publication Date: 1984
Subject: Begonias -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references (leaf 4).
Statement of Responsibility: B.K. Harbaugh and V.F. Cooper.
General Note: Caption title.
General Note: "April, 1984."
 Record Information
Bibliographic ID: UF00065198
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62522734

Table of Contents
    Historic note
        Historic note
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

U .
yC Gulf Coast Research and Education Senter
{-71 D7 IFAS, University of Florida
5007 60th Street East
Bradenton, FL 34203

Bradenton GCREC Research Report BRA1984-7 April 1984


B. K. Harbaugh and V. F. Cooper

Begonia x hiemalis, commonly known as Rieger begonias, were introduced into this
country in 1970 by Mikkelsen, Inc. of Ashtabula, Ohio.1 A wide range of floral and
vegetative characteristics among cultivars allows production of florist quality
plants in sizes ranging from 4-inch pots to 10-inch hanging baskets. The propagation
and production of this crop have received much attention (1, 5, 6, 7). Liquid
fertilization regimes for N and K levels (2, 4), the need for drip irrigation to
limit foliar disease (2), light levels (3, 6) and seasonal photoperiod requirements
(3, 5) have been established for production in temperate regions. Studies at the
Gulf Coast Research and Education Center were conducted to evaluate the effects of
irrigation system, controlled release fertilizers and photoperiodic control on
production of Rieger begonias in subtropical regions.

Materials and Methods

General: Rooted cuttings of 'Schwabenland Red' were planted in 6-inch pots
containing a medium gf 5 Canadian peat:3 sand:3 vermiculite:l. perli e (by volume)
amended with 5 lb/yd dolomite, 2.5 lb/yd3 hydrated lime, 2.5 lb/ydj single super-
phosphate, and 2 lb/yd3 Perk. Plants were drenched with BenlateO (1 lb/100 gal) and
DaconilO (1 lb/100 gal) solutions at planting for preventive disease control. Plants
were grown in h fan-and-pad-cooled greenhouse with maximum light intensity of 2000-
3000 ft c and average temperature of 700F (range of 60F night-90F day).

The height, width, number of inflorescences and a quality rating (1-5, l=best.)
were recorded for all plants at harvest. Immediately after these evaluations, plants
were placed in a laboratory designed for simulated home or office conditions. This
environment had a temperature of 73-78F, a relative humidity of 40-50%, and light
intensity of 110-150 ft c from 6 AM to 6 PM provided by cool white fluorescent lamps.
Potted plants were placed in individual saucers and water was applied until leaching.
Excess water was decanted after 1 hour. Data were analyzed by analysis of variance,
using Tukey's honestly significant difference (HSD) to compare specific means.

Experiment 1. A 2x2x3 factorial experiment in a randomized complete block design
was initiated on November 23, 1980, to study the influences of 2 irrigation systems,
2 controlled release fertilizer formulations and 3 fertilization rates. A single
plant represented an experimental unit and treatments were replicated 5 times.
Irrigation systems were either capillary mat (Vattex PO) or Chapin leader tube. The
controlled release fertilizers were Osmocote 14-14-14 or Osmocote 14-14-14:18-6-12
(1:1 by weight) at rates of 2.5, 5.0 and 7.5 lb/yd3. Plants were lighted with
incandescent lamps from 10 PM to 2 AM with 20 ft c at plant height for 3 weeks
immediately following planting.

1Appreciation is extended to Mikkelsen, Inc., Ashtabula, Ohio, for provision of
plants used in these studies.


Experiment 2: On November 28, 1980, 4 photoperiodic treatments were initiated
by lighting plants from 10 PM to 2 AM with 20 ft c for 0, 1, 2, 3 or 4 weeks
immediately after planting. A single plant represented the experimental unit and
each treatment was replicated 5 times in a randomized complete block design. Plants
received 5 lb/yd3 Osmocote 14-1-14 and were hand-watered.

Experiment 3. A xh4.factorial experiment in a randomized complete block design
was initiated on December 10, 1981, to study the interaction of photoperiod and
fertilizer rate on production time and growth of Riegers. A single plant represented
the experimental unit and each treatment was replicated 5 times. The photoperiods
were 2, 3, 4 or 5 weeks of 10 PM to 2 AM lighting at 20 ft c and fertilizer treatment!
consisted of 3.4, 5.2, 7.1 and 9.0 Ib/yd3 of Osmocote 14-1-1. A mat irrigation
system was used.

Additional plants were grown following Mikkelsen's recommendations using 6.7 oz
of a 150 ppm N solution from NutrileafO 20-20-20 fertilizer at every watering and
7 weeks of supplemental lighting from 10 PM to 2 AM.

At 2-week intervals starting on February 12, plants judged marketable were
harvested and data were-recorded.


Experiment 1. No differences in keeping quality of flowering plants were
observed during the 6 weeks plants were kept in simulated home conditions. Thus,
production characteristics (vegetative and flowering characteristics at harvest) were
used as the only criteria for evaluating effects of the various treatments.

There was no interaction of fertilizer formulation or fertilization rate with
irrigation systems. Plants grown with capillary mat irrigation had more inflores-
cences and displayed higher quality ratings than plants grown with tube irrigation
(Table 1). Plant height and width were similar with both irrigation systems.

An interaction was found for the effects of Osmocote formulations and fertiliza-
tion rates on all measured plant characteristics (Table 2). Increasing fertilization
rates from 2.5 to 7.5 lb/yd using Osmocote 14-14-14 produced Rieger begonias with
progressively higher growth parameter measurements. However, there were no measured
differences in the'height, width, number of inflorescences or quality ratings of
plants receiving 5 or 7.5 lb/yd3 of the 1:1 ratio of Osmocote 18-6-12:14-14-1. The
2.5 lb/yd3 rate of either formulation consistently produced smaller plants with
fewer inflorescences and inferior quality ratings.

Experiment 2. Plant height and number of inflorescences were not influenced by
the number of weeks of lighting (Table 3). An increase in the width and quality
rating was shown with increasing weeks of lighting. Plants receiving 4 weeks of
lighting had a width of 12.9 inches and quality rating of 1.6 compared to values of
8.2 inches and quality rating of 3.4 for plants receiving no lighting.

Experiment 3. There was no interaction between weeks of lighting and fertiliza-
tion rates on the growth of plants. Height and quality ratings were not affected by
weeks of lighting (Table 4). Width and number of inflorescences ranged from 13.1
inches and 19.9 inflorescences for plants receiving 4 weeks of lighting to 11.9
inches and 16.1 inflorescences for 2 weeks of lighting. Fertilization rates
influenced all growth parameters except height. The width of plants receiving rates
of 5.2, 7.1 or 9.0 lb/yd3 were greater than plants receiving 3.4 lb/yd3. The


number of inflorescences ranged from 13.7 to 19.9 and plant quality ratings from 2.7
to 1.6 for the 3.4 lb/yd3 and 7.1 1b/yd3 rates, respectively.

An interaction was found between weeks of lighting and fertilization rate when
measuring the production time. In general, production time decreased with increasing
fertilization rates and increased with increasing weeks of lighting (Table 5).
Plants receiving 2 weeks of lighting and the 9.0 lb/yd3 rate were harvested at 9.4
weeks compared to 11.4 weeks for plants receiving 5 week lighting and the 3.4 lb/yd3
rate (Table 5).


Irrigation System. Irrigation with capillary mats improved flowering and
quality ratings of Rieger begonias compared to plants grown with tube irrigation.
This may have been due to the relatively constant soil moisture level maintained
with capillary mat irrigation as well as greater availability of nutrients throughout
the season since nutrients are not lost by leaching. Capillary mat systems, in con-
junction with controlled release fertilizers, provide an alternative to tube
irrigation and injecting soluble fertilizers.

Fertilization. The.results from Experiments 1 and 3 indicate that a rate of
5 to 7 lb/yd3 of.Osmocote 14-14-14 will provide adequate nutrition for production of
high quality plants. Lower rates were inadequate and higher rates did not improve
growth or flowering in Experiment 3. Other cultivars (unpublished data) were
injured by high soluble salts at the 7.5 lb/yd3 rate which further suggests that
rates greater than 7.0 lb/yd3 are not beneficial with-capillary mat irrigation.

The controlled release fertilizers used in this study provided 2 formulations
with different release rates. At 70F, Osmocote 14-14-14 continues to release for
approximately.2-1/2 to 3 months, while Osmocote 18-6-12 releases up to 8-9 months.
Rieger begonias grown at a mean temperature of 700F showed no significant growth
differences in response to the 2 formulation treatments at each fertilizer level
tested. However, the interaction of formulations and rates of 5 and 7.5 lb/yd3
indicate that if a slower release of nutrients becomes necessary due to earlier
planting in the fall, or later plantings in spring when temperatures 'usually average
78-800F, then the 1:1 Osmocote 18-6-12:14-14-14 combination may be more effective
with less chance of soluble salt injury from-rapid release of nutrients (2).

Lighting. Wheh 5-7 lb/yd3 of Osmocote 14-i4-14 was used in conjunction with
capillary mat irrigation, 2-3 weeks of lighting was satisfactory for production of
high quality Rieger begonias. This is 5 weeks less time than suggested by Mikkelsen
(3) for production during the same time of year in more temperate regions. With
warm temperature, adequate light, optimum irrigation and fertilization regimes, no
benefits would be gained by lighting more than 2-3 weeks in subtropical climates.

Comments and Precautions. Rieger begonias require a great deal of attention to
detail throughout the cropping cycle for successful production. Immediate potting of
shipped plants, preventative disease control practices (to include removal of
injured foliage and spraying), removal of oversized leaves or terminals to shape the
plant, greenhouse temperature control (average temperature 70-740F, minimum 60F
night, maximum 90F day), light intensity control (2000-3000 ft c), and staking of
certain varieties are examples of the care and maintenance these plants require.
However, results indicate 10-11 week winter cropping times in subtropical climates or
4-6 weeks less time than winter production schedules outlined by Mikkelsen (3) for
temperate climates. This reduction in production time may offset some of the mainte-
nance requirements; thus, winter production of Rieger begonias in subtropical
climates may be an alternative for those growers wishing to diversify.*

Literature Cited

1. Cohl, H. A., and B. C. Moser. 1976. Environmental control of shoot initiation
by Rieger begonia leaf cuttings. HortScience 11:378-379.
2. Harbaugh, B. K., and G. J. Wilfret. 1982. Correct temperature is the key to
successful use of Osmocote. Florists' Review 170:21-22.
3. Mikkelsen, J. 1973. Simplified instructions for Rieger elatior begonia growth.
Florists' Review 153(3957):36.
4. Nelson, P. B., D. M. Krauskopf and N. C. Mingis. 1978. Nitrogen and potassium
requirements of Rieger begonia. J. Am. Soc. Hort. Sci. 103:603-605.
5. White, J. W., J. Holcomb, and T. Maczko. 1973. Rieger elatior begonias progress
report. I. Pa. Flower Growers Bul. 263. pp 6-9.
6. White, J. W., J. Holcomb, and T. Maczko. 1973. Rieger elatior begonias research
at Penn State progress report. II. Pa. Flower Growers Bul. 264. pp 4-5.
7. Witte, W. T. and T. J. Sheehan. 1974. Effects of media and fertility on growth
and flowering of Rieger begonia. Proc. Fla. State Hort. Soc. 87:508-512.

Table 1. Main effects on 2 watering systems on growth of Rieger begonia.
Foliage Foliage
Irrigation height width Inflorescences Quality
system (inch) (inch) (No.) ratingy

Tube 5.6 aZ 11.2 a 9.7'a 2.7 b
Capillary mat 6.0 a 11.8 a 11.3 b 2.4 a

ZMean separation within columns by Tukey's HSD, .01 level.
YMarketability rating from 1-5, with 1 = best.

Table 2. Effects of 2 controlled release formulations and 3 fertilization rates 6n
the growth of Rieger begonia.
Growth parameters
Foliage Foliage
Osmocote treatments height width Inflorescences Quality
Lb/yd3 Formulation (inch) (inch) (No.) ratingz

2.5 14-14-14 4.6 ay 9.1 a 3.8 a 3.8 c
2.5 Combinationx 4.2 a 8.9 a 3.4 a 3.8 c:-

5.0 14-14-14 5.7 b 11.4 b 8.8 b 2.8 b
5.0 Combination 6.0 b 12.2 b 11.7 b 2.2 b

7.5 14ul4-14 7.6 c 13.8 c 19.7 c 1.2 a
7.5 Combination 6.8 bc 13.7 be 15.6 bc 1.6 ab

ZMarketability rating from 1-5, with 1 = best.
YMean separation within columns by Tukey's HSD, .01 level.
XA 1:1 ratio by weight of Osmocote 18-6-12 and Osmocote 14-14-14.

Table 3. effect of weeks of lighting from 10 PM to 2.AM (long days) on the
growth of Rieger begonias.
Growth parameters
Foliage Foliage
Lighting height width Inflorescences Qualit
(weeks) (inch) (inch) (No.) rating

0 5.2 ay 8.2 a .13.8 a 3.4 b
1 5.6 a 10.0 abc 13.0 a 2.8 ab
2 7.2 a 11.3 bcd 15.8 a 2.0 a
3 5.9 a 12.7 cd 13.4 a 2.0 a
4 6.1 a 12.9 d 16.2 a 1.6 a

Marketability rating from 1-5, with 1 = best.
Mean separation within columns by Tukey's HSD, .01 level.

Table 4. Main effects of weeks of 10 PIM to 2 AMV lighting (long
-4 D h f i b

days) and fertili-

atL on r es on the growj oj eIger eo .
Growth parameters
Foliage Foliage
Lighting height width Inflorescences Qualit
(weeks) (inch) (inch) (No.) rating

2 7.6 ay 11.9 a 16 ab 2.1 a
3 8.0 a 12.2 ab 18 ab 2.1 a
4 8.1 a 13.1 b 20 b 2.1 a
5 7.8 a 13.1 b 15 a 1.8 a
Osmocote 14-14-14
S 3.4 7.4 a 10.9 a 14 ab 2.7 c
5.2 7.7 a 12.7 b 18 ab 2.0 b
7.1 8.2 a 13.4 b 20 b 1.6 a
9.0 8.1 a 13.4 b 17 a 1.*8 ab

ZMarketability rating from 1-5, with 1 = best.
Mean separation within columns by Tukey's HSD, .01 level.

Table 5. Effect of weeks of 10 PM to 2 AM lighting (long days) and fertilization
rates on the production time of Rieger begonias.
Production time (weeks)
Lighting Lb/yd Osmocote 14-14-14
(weeks) 3.4 5.2 7.1 9.0

2 10.6 abcz 9.8 bc 9.8 bc 9.4 c
3 10.2 bc 10.6 abc 10.6 abc 9.8 be
4 10.6 abc 10.6 abc 10.6 abc 11.0 ab
5 11.4 a 11.4 a 11.0 ab 10.6 abc

ZMean separation within or across columns by Tukey's HSD, .05 level.

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