Report from the Southern Trials Part I

August 22, 2003 - 11:21

Florida puts some favorites to the test.

Well it's finally feeling like a normal Florida summer, with
a half inch of rain every afternoon and temperature and humidity at around 90.
Since we had a relatively dry summer, a lot of plants that traditionally give
up the ghost in June have persisted into August. That's good because it tells
us a lot about heat tolerance. Oddly enough, powdery mildew was not a problem
this year, as it had been in the past. With over 340 entries and 19 basic
categories of plants in the 2003 spring/summer trials at the University of
Florida, there is a lot to cover.

The trials are planted each year into ground beds amended with
mushroom compost at 1 yard per 100 sq.ft.; the pH of the beds ranges from
6.2-6.7; and a think layer of aged pine bark is applied after the soil is
prepared. At planting, 72-cell liners are placed directly into the beds on
12-inch centers and 4 grams of Osmocote 18-6-12 is incorporated around each
plant. Plants are then watered-in overhead by hand, and subsequent watering is
done through drip tubes similar to commercial vegetable production irrigation
systems. Plants are evaluated every other week for initial flowering and peak
flowering, evaluated on a five-point system and rated on performance, diseases,
pests, etc. We do not apply any fungicides or pesticides, except glyphosate to
control weeds. After the first weeks of planting, we also do not deadhead,
pinch or trim, unless an entry is so vigorous it threatens the ratings of
entries surrounding it. The trials ran from approximately April 1 to July 31.

To get the full story with data, check the trials Web site,
(http://hort.ifas.ufl.edu/floriculture/springtrials2003), so you can compare
what is said here with pictures taken every two weeks. So here are the plants
in the groups we classified on the Web site to facilitate crossover. Also, due
to the number of cultivars presented here, please use the Web site to locate
sources for this material.

Angelonia

This year, the Angelonia were the field portion of the
Florastar Elite trials, as well as being one of our focus crops, so there were
fewer entries, and the trial does not cover the scope of the industry by any
means. It was great to have a chance to do some field trialing of these plants,
as they have so much potential, and the genetics are there for some incredible
advancements in the near future. I hope we will be doing these again once some
of the new releases make it on to the market.

We trialed from the Angelface (Proven Winners), Angelmist
(BallFlora Plant) and Carita (The Flower Fields) releases, all of which had
good performance in the garden. In the entire season, there was only one strong
flush of flowering, though it lasted roughly six weeks and garnered a very
strong performance. This is partly because we started with liners rather than
finished materials. All entries performed very well; however, the amount of
time they spent growing and not flowering reduced their overall ratings. The
highest marks went to 'Angelface Blue' and 'Angelmist Purple Stripe' for
earlier flowering and longer bloom seasons.

Annuals

There were 81 "annuals" this year, and we lumped
all the plants that were not focus crops into this category. There were some
star performers here that deserve a lot of credit for exceptional performance.
These are plants that had superior performance this year.

Intensia Phlox. Top
Performance in the garden. Proven Winners really struck gold on these plants.
Normally Phlox drummondii hybrids are short-lived, cool season annuals, but the
Intensia series were far superior to anything we have seen before. The plugs
were in bloom when planted and began to show some signs of foliar loss in August,
otherwise they stayed at a perfect five rating throughout the entire summer.
This is a crop to be looking at for spring and summer sales.

Doublette Begonias.
These double hybrids of Begonia sempervirens-cultorum were incredible in full
sun throughout the season; through today, they remain in full bloom with no
disease or insect problems at any time. In our consumer and student
evaluations, these plants also came out as top picks. It was almost boring how
consistently great they were!

Dreamland Zinnia.
Again, this not a plant we expect to hold up through summer in Florida. Add to
this, that we did not deadhead spent flowers or clean the plants in any way.
Throughout the season, these plants held up and are only now -- in late July
and August -- starting to succumb to leaf spot, Anthracnose and Botrytis. A
really strong performer for zinnias, definitely heat tolerant and disease
resistant.

Diva Vinca. This is
the second year for trialing this series from Danziger "Dan" Flower
Farm, and again, they have performed excellently. There is some variability in
the series, with Salmon Pink having the lowest vigor in both seasons, but all
are good performers. These plugs went through a record late frost and still
performed all season long. There were some losses of lower foliage towards the
end of July, with the advent of summer rains, but still a good strong showing
from this series.

Calibrachoa

This crop was part of the Flora Star Elite trials and a
field focus crop last year. The results of the greenhouse portion of the trials
were in the July issue of GPN, and honestly calibrachoa has a better life as a
winter or early spring crop for the Deep South rather than the late season. Any
entries planted late, due to shipment, had bad overall ratings because without
the benefit of early cool temperatures, the plants could never get up to size
and give a good showing in the landscape.

One might argue that calibrachoa is not a landscape crop,
but why shouldn't it be? It has the potential to be a very strong, early spring
crop and can be winter planted in the Deep South for early spring sales. We
trialed 22 cultivars, and there were huge differences in performance based on
genetics. The really bad ratings all went to late entries. Note that the period
between weeks 20-24 was the peak season for this group.

Double Impatiens

This crop was part of the Flora Star Elite trials and a
field focus crop. Again, this is not a crop traditionally thought of as
landscape material, much less full sun landscape material, but we wanted these
plants in the field to look at sun, heat and humidity tolerance. These plants
contracted Rhizoctonia fairly early in the season, so we actually looked at
Rhizoctonia effects as well. Top ratings for double impatiens went to 'Fiesta Salsa
Red' (BallFlora Plant), 'Double Up White' (Bodger Botanicals) and 'Fiesta
Burgundy Rose' (Ball Flora Plant), for surviving the trials and having a better
presentation of flowers, as well as a vigorous growth under some pretty tough
conditions. Overall, ratings were fairly low in this group due to some insect
pressure, as well the presence of Rhizoctonia in that bed.

Double Vegetative Trailing Petunia

This was a field trial focus crop. Double vegetative
petunias are an expanding market with many different genetics available. During
early season performance, all entries performed beautifully and had high
ratings; the major impact on ratings came in late season. We actually had
petunias still blooming in August, which for Florida is nearly unheard of, but
this year, disease pressure was lower and entries lasted longer. Personally, I
was really impressed with the Double Wave series by PanAmerican Seed, which
continued to flower into July and August. Remember that a rating over 3.0 for
the season is very strong!

Verbena

This is another group of plants that dodged a bullet this
year in our trials, as we had no powdery mildew at all. For verbena in the Deep
South, that pathogen is one of the main reasons for late-season performance
melt down. This year, many of the entries were still attractive in August; they
weren't at peak by any means but still of landscape value, which is very
impressive. 'Donalena Red' received the highest ratings although both Donalena
and Veralena varieties got a lot of interest during the industry field days in
late May. Many of the Tapestry series were very strong as well and still
receiving high marks as we head into August. All in all, it was a very good
year for verbenas.

The authors would like to thank all contributing companies
and sponsors for their support of the 2003 spring/summer trials. The 2003
winter trials are planted October 15, and spring 2004 trials planted April 1.
Our major Floriculture Field Day will be held May 19-20, 2004.

About The Author

Rick Schoellhorn is extension specialist and Erika Berghauer is trials manager at University of Florida, Gainesville, Fla. They can be reached by phone at (352) 392-1831 or E-mail at rksch@imail.ifas.ufl.edu.

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