PROJECT FINAL REPORT
Project: Development of Vegetable and Flower Production in Dalmatia
Principal investigator: Slavko Perica, PhD
Research Topic
The objective of the project was to improve the extant vegetable and flower production in
Dalmatia by introduction of new species, cultivars and technologies. The market is
replete with quite a number of vegetable cultivars for commercial production, mainly
from abroad. Therefore, field experiments were made with new tomato, pepper,
watermelon and endive cultivars with the aim of determining the most suitable ones for
growing under local environmental conditions. Field experiments with new tomato,
pepper and watermelon cultivars were carried out for two years in Petrovo polje (Drniš),
Imotsko polje and in the Knin area. The experiments were established as per design
common in conducting field trials (Vasilj, 2000), with measurements of relevant yield
and quality indicators. Furthermore, research of six endive cultivars was performed on
three sites, viz. Imotski, Komiža and Trogir. A new growing technology was introduced
on each location with respect to all species (bar the endive), i.e. through application of
black mulch combined with the drip-irrigation system. All production matériel requisite
for the experiments, from transplants to pesticides, was provided from project funds. The
region of Dalmatia is rather favorable for flower-growth in greenhouses thanks to the
local climate (temperature, clear days). Unfortunately, over 90% of the overall flowerproduction concerns the gerbera, which often results in market saturation and low prices,
as well as in deficit of other flower species on the market. Due to a number of issues
occurring in cultivation in soil (soil pH, problems with diseases and pests on account of
monocultural growth, etc.), the system of flower growth in substrates (soilless) has been
introduced in the production framework in recent years. Producers mostly adhere to
technologies as developed in the Netherlands and other Western Europe countries. The
anthurium is a species that has not been cultivated locally, so the objective of an
experiment with seven anthurium cultivars was to introduce a whole new species in the
flower-production with a subsequent aim of increasing the supply. Simultaneously, one
wanted to assess the values of respective cultivars and introduce a new growth
technology. As noted, the growth technology, and particularly nutrition, are based on
experiences from The Netherlands, so we kept track of the nutrient solution composition
in various substrates (rock-wool, peat, rice bark, coconut bark, mixture of rice and
coconut bark) with four gerbera producers in the area of Split. By regular measurement of
the ratio of nutrient and its concentration in the nutrient solution one can timely resolve
the issues in nutrition of plants, occurring frequently in such a production system. More
information about carried experiments could be find in the references cited below, in the
next few months the rest of the results will be published in the Agronomski glasnik,
Zadrugar and Gospodarski list.
Bućan, L., Dumičić, G., Gudelj-Velaga, Ž., Goreta, S., Perica, S. (2001) Yield and
quality components of pepper cultivars. Collection of summaries 37th croatian
symposium on agriculture with an international participation Opatija, p. 207
Gudelj-Velaga, Ž., Bućan, L., Perica, S., Goreta, S. (2001) Yield and quality components
of determinate tomato cultivars. Collection of summaries 37th croatian symposium on
agriculture with an international participation, Opatija, p. 209
Technology Description
Production properties of the leading seed-manufacturers’ new cultivars under
Mediterranean conditions were investigated during the experiments. Throughout the
anthurium cultivation, new species, cultivars and modern technologies were applied,
while the nutrient solution composition in substrates was observed with the gerbera.
With respect to the species diversity and the space of cultivation, technical processes can
be divided in three groups:
1. Cultivation on black mulch with the drip irrigation system
2. Outdoor cultivation without mulch
3. Soilless cultivation
1. Cultivation on black mulch was applied with the watermelon, pepper and tomato.
This kind of growth necessitates autumnal deep ploughing. In springtime the basic
fertilization and cultivating is to be made, the soil should be rendered into fine
fragments, which enables fitting the sheeting tightly onto the ground. The sheeting
and irrigation piping are to be set 15-20 days prior to planting. Prior to fitting the
sheeting, it would be beneficial to use soil insecticide. Upon planting, irrigation and
crop-control are mandatory, as well as replanting of damaged and dead plants, within
eight days after the very planting. Plant protection is to be applied when necessary,
with weekly crop control. Final treatments should be performed with short-lived
pesticides, because such a manner of growth facilitates the harvesting even as much
as 15 days earlier. Irrigation is also to be made when required, with requisite control
of nozzles blockage. The drip irrigation system enables easier application of
fertilizers, so that additional nutrition can be performed either based on the observed
status of nutrients or upon recommendation. The harvest is recurrent, so care should
be taken of passageways for the equipment and people in order to avoid damages to
crops, i.e. the very yield.
2. Open field cultivation without mulch has been applied with the endive for autumnal
cultivation. It is desirable to grow the endive after the species that render the soil
cleansed and loosened, which is to be cultivated 15-20 days prior to planting with
mineral fertilizers applied. The immediate step after the planting is irrigation. Thus
the shock is reduced and the plant starts growing instantly. Irrigation is to be
performed all the way until the harvesting, pending on precipitation. Plant protection
is to be applied when necessary, with requisite weekly controls. Care should be paid
to final treatments with pesticides.
3. The technology of growth in substrate has been applied with the anthurium. In view
of modern technologies, either specialist supervision is required, or producers should
have extensive experience in flower-cultivation. Plants can be planted in various
substrates applied under the system. Each plant is equipped with a trickle through
which it receives fertilizer and water.
The next step is to set up protective
overshadowing netting and an air humidity regulatory system. There should also be a
heating system established, for the temperature should not drop under 15°C.
Protection from plant diseases and pests is to be implemented as necessary, with
weekly specialist supervision. Additional nutrition and irrigation are to be performed
several times a day, subject to the season, developmental stage and the species
requirements. The ion concentration in nutrient solutions is a significant yield factor.
Consequently, chemical analyses of the ion concentration in nutrient solution provide
for a proper insight and optimal nutrition of plants. Control of substrate salts should
be carried out every 4-6 weeks.
Economic Analyses
Economic analyses for tomato, pepper, watermelon, endive and anthurium are attached
herewith. Under each manner of growth, varieties with average yields were selected, and,
based on their return a calculation of variable costs coverage has been made.
Applicability
The technology of tomato, pepper, watermelon and endive cultivation, under research in
the pertinent period, proved to be applicable on family farms. Possible limitations in
production could rear in the line of financial capability of farm-estates. Introduction of
this technology requires additional investments, which do pay by manifold however, so
the farmers have adopted it after all. As to the anthurium-growth under the soilless
system, a possible issue lies in procurement of propagation material and equipment, all of
which have to be imported for the time being, as well as access to adequate laboratory
facilities in the vicinity for the purposes of chemical analyses of nutrient solution.
Notwithstanding, a somewhat opulent initial investments are needed, as well as previous
experience in flower-cultivation in substrates, but this field of agriculture is ever so
profitable, and the local competition is virtually almost nil.
Farmers’ Evaluation
Farmers were satisfied with proposed solutions, for the advancements in technology had
granted them significant financial benefits, and they were also enjoying constant support
of the research team throughout the project, even in respect of other issues festering
production on their estates. It was also obvious that the technology would spread onto
other estates in the region dealing with this particular type of production.
Quantitative Data
Since the experiments were made on quite a number of locations and with various
producers, and in the light of the fact that on certain occasions it was not that possible to
observe the progress of experiments with extreme precision, let us set forth below only
the complete and relevant investigation findings.
The yield and quality components of seven pepper cultivars (Albatros, Dennis, Golden
Summer, PS 379494, PSR 379294, Shy Beauty and T132) were surveyed for two years in
Imotsko polje. The mulch black technique was applied, along with the drip irrigation
system. The harvest took 80 days, with yields from 36.3 t/ha (the Shy Beauty) to 59.1 t/ha
(the Albatros). The highest average fruit weight was noted with the Dennis cultivar (140
g) of dark-green colour, and the lowest with the Albatros and Golden Summer (95 g) of
yellow colour. The Dennis cultivar also had the highest fruit height (12 cm), while the
highest fruit diameter was observed with the Shy Beauty cultivar (8.5 cm).
A field experiment with seven cultivars of determinant tomato (BSS 239, Bologna,
Celebrity, Daisy, Erato, Marmande and Hector) was made in Imotsko polje through twoyear research. Pot seedlings were replanted onto mulch black polyethylene sheeting with
drip irrigation. The harvest took 60 days both years, and the yields were from 62.11 t/ha
with the Celebrity to 100.05 t/ha with the BSS 239. The highest average fruit weight was
found with the Hector cultivar (110 g), and the lowest with the Erato (91.1 g). All
cultivars had fruit of round shape and firm.
A variety experiment with ten watermelon cultivars (Crimson Glory, Eureka, Crimset,
Royal Majesty, Sugar Delicata, Paladin, Farao, Top Gun, Crimson Sweet, Sultan) was
carried out through two-year research on two locations, Petrovo polje and Imotsko polje.
Pot seedlings were replanted onto mulch black polyethylene sheeting with drip irrigation.
The harvest took 25 days, with yields from 43.6 t/ha with the Eureka to 69.72 t/ha with
the Farao. The Sultan had the highest average fruit weight (7.84 kg), while the Eureka
had the lowest (6.3 kg).
Yield components of seven anthurium cultivars (Barbara, Monique, Patricia, Christina,
Jerichona, Leigh, Diana) were investigated for two years. Seedlings were planted in
greenhouses according to the soilless system. The highest number of Class 1 flowers was
yielded by the Diana cultivar (2.8), while the Barbara returned the least (0.17). The most
of Class 2 flowers were found at the Jerichona cultivar (5.32), and the least with the
Barbara (0.9). The most of Class 1 leaves were picked from the Monique (2.07), and the
least from the Barbara (0.33). The most Class 2 leaves were picked from the Jerichona
(2.12), and the least from the Monique (0).
A field experiment with six endive cultivars (Perfect, Avance, Ortolani, Samy, Bossa,
Ciarda) was carried out through a two-year survey on three sites in Imotski, Komiža and
Trogir. Pot seedlings were planted into flower-beds, and were watered by sprinkling. The
harvest returned from 37.87 t/ha of the Samy in Komiža up to 69.24 t/ha of the Ciadra in
Imotski. The highest average market-head weight was noted at the Ciarda cultivar (686
g), grown in Imotski, while the lowest was observed with the Samy (340 g), grown in
Komiža.
Control of nutrient solution in substrates was carried out with twelve gerbera cultivars
(Janara, Kabana, Sky Line, Avalon, Farinda, Rulet, Marmara, Mamut, Lurd, Dino, Testa
Rossa, Figaro) in the environs of Split at four producing locations. Many a deficiency in
nutrition technologies was noted during the analyses of nutrient solutions. It was
observed that the values deviated both in certain growth substrates (rock-wool, peat, riceshell, coconut shell, rice-coconut shell-mixture) as well as in various applied nutrition
approaches. Based on the analyses, producers were given recommendations on how to
balance the nutrient solutions with the pertinent crop requirements.
Qualitative Data
Conversion from one technology to another, particularly in case of a new growth system
being somewhat more complex, often results in initial production drops. New growth
technologies require a more extensive know-how and experience from the producers as a
rule. Return of the pepper, tomato and watermelon can be increased, as verified by global
statistics. In order to achieve that, a constant crop control and regular support by staff
services is requisite. A classic example concerns the anthurium – due to long-term
growth, the yield and costs are hard to represent in real terms within a short period. Thus,
neither the yield nor the profit have been as expected. Furthermore, as for the gerbera,
quite the opposite from the expected results as regards high concentrations of nutrients in
substrates, the investigations showed that the anomalous ratio of particular nutrients is a
much more serious issue. The reason lies in the very feeding of crops as per visual
assessment. Producer's understanding of the nutrient solution composition is limited to
retaining the pH solution at the level of 5-6, and the electrical conductivity within the
range of 1.1-1.3. However, these two parameters are not sufficient to facilitate optimal
supply of nutrients for plants in order to accomplish high production rates. Thus, an
improvement in production may be expected only upon regular control of the nutrient
solution composition, which should be made every 4-6 weeks at least.
Conclusions
Application of new technologies require specialist supervision and more extensive knowhow on the producers' part, which does demand additional expenditures, but the
calculations indicate that new techniques and technologies are pretty worth the effort.
Apart from the profit, another advantage lies in preservation and protection of the
environment on account of purposeful application of pesticides and fertilizer based on
chemical analyses of soil and plant tissue. Introduction of new cultivars and species
enriches the supply, and makes extensions of harvesting possible; thus, it is that much
easier to organize the very production. The chemical analyses results expose a need to
keep regular track of the ion composition in nutrient solutions. That would make possible
the optimal ratio of nutrients, which would have direct implications on the increase in
gerbera flowers production.
Enclosed files:
1. Variable cost coverage for tomato
2. Variable cost coverage for pepper
3. Variable cost coverage for watermelon
4. Variable cost coverage for endive
5. Variable cost coverage for anthurium
Principal investigator
Slavko Perica, PhD