UNIVERSITY OF AGRICULTURAL SCIENCES AND VETERINARY MEDICINE CLUJ NAPOCA HORTICULTURE FACULTY. Eng. Georgeta Minodora SABO (BURDUHOS) SUMMARY

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1 UNIVERSITY OF AGRICULTURAL SCIENCES AND VETERINARY MEDICINE CLUJ NAPOCA HORTICULTURE FACULTY Eng. SUMMARY RESEARCH REGARDING THE BIOLOGY AND PLANTING MATERIAL PRODUCTION TECHNOLOGY AT SOME WOODY SPECIES USED FOR HEDGES AND TRIMMED FORMS Scientifically Coordinator, Prof. univ. dr. Dumitru ZAHARIA CLUJ-NAPOCA

2 Green spaces, hedges and clipped forms are used for decorative and utilitarian purposes (PETRESCU, 1983). Hedges are plantations formed from shrub or arborescent species which are disposed in one, two or three rows, following a contour which can be straight or even sinuous. These plantations can consist from one or more species (NEGRUTIU, 1980, ILIESCU, 2003 DUMITRAŞ et al., 2008). Clipped forms are realized from coniferous or deciduous species which support cutting and can be easily driven to form different geometrical or natural forms. This characteristic of the plants is called plasticity (SERMON et al., 1973). The cutting technique of the ornamental shrubs is known as topiary art, being a method of plants formation by cutting the leaves and the threes and shrubs branches, so that they maintain their clearly defined geometrical or fanciful shapes org/wiki/topiary). Indifferently the function which they perform (decorative or utilitarian), the way of the growth and development of the species from which they are realized, hedges from the green spaces must fulfill a number of characteristics to be given them a decorative value. The most important characteristics are: to be compact, free of gaps, uniform from the surface of the soil to the upper limit, to bear repeated cuttings and trimming, to maintain the realized shape for a long time without too much cutting and trimming requirement, to recover quickly after cutting and trimming operations, to have a good resistance to the different soil and climate conditions (PETRESCU, 1983). Ornamental trees and shrubs increase the amount of humus in the soil, improve soil structure and permeability, changes the ratio of cations and ph (ILIESCU, 1998). Also, the woody trees and shrubs species which are recommended for hedges, fulfill sanitaryhygienic function too. Green vegetation can act as a true "sound barrier". In general, in modern cities, the maximum intensity of noise reaches db, against db which is registered in rural settlements (MUJA, 1994). Hedges forms a very rich transient ecosystem (eco-tone) consisting various plant and animal populations that occupy a certain habitat ( In urban areas, the vegetation contribute actively to air oxygenation, reduce carbon dioxide content from the atmosphere, reducing chemical pollution, it retains dust particles 13

3 or dust, reducing noise and mitigating climate factors in excess, thus contributing to the protection of population health (MUJA, 1994). This thesis is divided into 6 chapters, containing a number of 250 pages, 91 tables, 40 figures, 32 graphs, 9 posters. The documentation for the correct understanding of the topic taken under study, the research organization, carriage of the observations and measurements, the statistical processing, the interpretation and presentation of results and finally the development of the thesis consisted in the consultation of 129 references. Preliminary results of research over the years were materialized in 6 scientifically papers presented and published in national and international symposiums (see bibliography). Motivation. The high requirements for planting material used in public landscaping and private spaces, require a strong action to improve the production technologies for ornamental trees and shrubs planting material. From these, species of the genus Ligustrum, Buxus and Taxus, often used for hedges and clipped forms, enjoy a higher interest and greater demand, therefore these species were the subject of this research. The main purpose of the research was to improve rooting technology of the cuttings for the following species: Ligustrum vulgare L., Buxus sempervirens L. and Taxus baccata L., to increase the percentage of rooted cuttings and to increase the quality of rooted plants which are meant to be planted. At the same time reducing the production costs and increasing the economic efficiency in the field was aimed too. In order to achieve the main purpose, the following objectives were taken into consideration: - the determination of the influence of the Ligustrum vulgare L. cuttings characterristics and the treatment with Radistim 2 upon the cuttings rooting and number of roots; - the determination of the Ligustrum vulgare L. cuttings rooting process quality under the influence of the cuttings characteristics (thickness and number of nodes) combined with the treatment with Radistim 2 upon the shoots growth at the transplanted plants; - study of the fertilization effect on Ligustrum vulgare L. rooted cuttings upon their growth, in order to form new plants; - study regarding the effect of the stimulating substances upon the Buxus sp. and Taxus sp. cuttings rooting; 14

4 - study regarding the optimal composition of the rooting substrate using several components and the establishment of the substrate influence upon the Buxus sp. and Taxus sp. cuttings rootedness; - establishment of the optimal variants from economical and technological point of view in the production of planting material at Buxus sp. and Taxus sp.; - study regarding the influence of the substrate composition, of the cutting type (simple, with heals, with one, two or more ramifications) and the treatment with Radistim 2 upon the rooting percentage, number and length of the roots at Buxus sempervirens L.; - study regarding the growth and plants formation at Buxus sempervirens L. after first and second year from the rooting, by monitoring the plants growing using some indicators. The experiences regarding the rooting methods of the cuttings and planting material formation at the woody species used for hedges and clipped forms were conducted in the greenhouses of the Floriculture and Ornamental Arboriculture Department from the University of Agricultural Sciences and Veterinary Medicine from Cluj-Napoca in In order to achieve the goal and objectives of the research several experiments were conducted which aimed the improvement of the cuttings rooting technologies at the mentioned species as follows: A. Experiences regarding the influence of the cuttings thickness, number of nodes and treatment with Radistim 2 upon the Ligustrum vulgare L. cuttings rooting (2008). 30 cuttings were prepared for each thickness variants, a total of 18 variants, respectively 6 variants for the thick cuttings, with a diameter > than 5 mm, 6 variants for the medium cuttings, with the diameter ranging between 4 and 5 mm, and 6 variants for thin cuttings, with a diameter < than 4 mm, each of these having three variants depending on the number of nodes (with 5 nodes, with 4 nodes and of peak). B. Experiences regarding the influence of the cutting thickness, number of nodes and treatment with Radistim 2 upon the growth of the shoots at Ligustrum vulgare L. plants transplanted into pots. The experience was conducted in May The biological material was provided by transplanted plants which came from Ligustrum vulgare L. rooted cuttings in the same year from the Ornamental Arboriculture Department 15

5 from UASVM Cluj-Napoca (previous experience). Data were statistically processed and interpreted with analysis of variance method. C. Experiences regarding the influence of fertilization upon the growth and plants formation of the Ligustrum vulgare L. rooted cuttings (2009). To follow the evolution of the growth and plant formation, a year after the rooting of Ligustrum vulgare cuttings, in 2009, an experience was organized in which plants were fertilized. One of the followed factors was the fertilization type with three graduations: without fertilization (witness variant), Ferticare SK and Razormin fertilizers. Ferticare SK is a complex ferti-lizer with a high content of mineral substances (62.5 %), from which N 15%, K 15%, Mg 2.5 % and a complex content of micronutrients. The fertilizer has a crystalline form and has a high solubilization capacity. Razormin fertilizer has a moderate mineral nutrient content: N total 4%, P total 4%, K total 3%, Fe 0.1%, Zn 0.08%, Cu 0.02%, Mo 0.01%, but it contains amino acids 7%, polizarides 3%, organic matter 25% and growth and rooting stimulants too. It is applied in concentrations of %. To determine the effect of fertilization on one year old Ligustrum vulgare L. plants growth and development, the following biometrical measurements were conducted: plant height (cm), bush diameter (cm), number of shoots/plant. Observations and measurements were started at 5 weeks after the experience started and ended one week after the last fertilization. The data were statistically calculated and interpreted by the method of analysis of variance and Duncan test. D. Experiences on the effect of substrate composition and treatment with Radistim 2 upon the Buxus sempervirens L. and Taxus baccata L. cuttings rooting (2009). The experiences of both species were bifactorial and had the following factors: Factor A: rooting substrate composition, with four graduations: a 1 - perlite 100% (Wt); a 2 - perlite + sand (1:1); a 3 - perlite + peat (1:2); a 4 - vermiculite + peat (1:1). Factor B - treatment with stimulators (Radistim 2): b 1 - untreated with Radistim 2 (Wt); b 2 - treated with Radistim 2. 16

6 By the factors combination eight experimental variants were obtained. During the experiences ongoing o series of observation and measurements were made. Raw data were statistically calculated and settled a number of objectives, from which the following ones can be mentioned: physical, chemical and hydric characteristics: specific mass, porosity, water retaining capacity, chemical reaction (ph), physiological response, the number of rooted cuttings, root number and roots length at rooted cuttings. Quantitative index values were statistically processed and interpreted by the analysis of variance method. E. Experiences regarding the influence of the cutting type, of the substrate and treatment with Radistim 2 upon the Buxus sempervirens L. cuttings rooting (2010). To establish the influence of the substrate, of the cutting type and treatment with Radistim 2 upon the Buxus sempervirens L. cuttings rooting, a polifactorial experience was conducted. By the combination of the three factors and their graduations 56 experimental variants were obtained, each of them having three repetitions. Substrate composition was determined and accomplished in four variants and were used the following components: brown fibrous and ground peat (oligotrophic), perlite and river sand. At variants where mixtures were used, the components were added by equal parts in volume. The cutting type was realized by shaping them in seven ways: one variant with simple peak cutting, unbranched, three variants with simple cuttings and three variants with cuttings with heals, each of them having one, two or three ramifications. Before placing the cuttings into the rooting substrate, half of them were treated with Radistim 2, the other half of them remained untreated. Treatment was done by placing the cuttings into the Radistim 2 powder. Observation on biological material consisted in establishment, for each experimental variant, of the following elements: number of rooted cuttings, number of roots formed, root length (cm). The results were statistically processed and interpreted in the text by analysis of variance and Duncan test method. Throughout the rooting period measurements were made regarding the microclimate conditions: temperature from the greenhouse compared to that from outside, temperature from the rooting substrate, air humidity from the greenhouse compared to that from outside, light intensity from the inside and assessment of the nebulosity. 17

7 F. Studies regarding the growth and plants formation rhythm at Buxus sempervirens L. which were obtained from cuttings, at one and two years after rooting (2010). To determine some morphological characteristics of Buxus sempervirens L. plants and their growing rhythm three plants of one respectively two years old were randomly selected. Plants were part of the specimens obtained from Buxus sempervirens plants in 2008 and Each of the six plants was subjected to biometric measurements: plant height (cm) diameter of the transplanted plants (cm), root weight (g), weight of stems, shoots and leaves (g), green leaf weight (g); strains and shoot weight (g), foliar surface/cm 2, number of leaves per plant, number of leaves/main shoots, number of secondary shoots, number of nodes/shoot, pot size (cm), weight of the plant with soil (g), weight of landless plant (g) (shoot + root + stem + leaves). Biometric measurements were obtained using a ruler, electronic balance and AutoCad software, a program with high accuracy. With AutoCad soft leaf surface was determined. To determine leaf surface were followed the following steps: the leaves were removed from the plants, then were scanned using the scanner by setting Tiff option, an option that retains the shape of leaves in 1:1, then the obtained photographs were imported into AutoCAD, each leaf was numbered approximately in decreasing order of the size, the outline of each leaf was monitored using the cursor and closing contour with so the leaf surface was obtained. The same order was followed for each leaf surface and then the total leaf area for the entire plant was determined. The experimental results which were conducted for three years (during ) and had as objectives the improvement of seedlings production methods and planting material formation at some dendrological and ornamental species (Ligustrum vulgare L., Buxus sempervirens L. şi Taxus baccata L.), species which have a high request for hedges and topiary art forms, allows the enunciation of the following conclusions: 1. Regarding the Ligustrum vulgare L. cuttings production. The best results regarding the cuttings rooting were obtained at cuttings of peak, which had a medium thickness with the application of Radistim 2 rooting stimulator. The quality of the rooted cuttings expressed by the number of formed roots is very important and from this point of 18

8 view, the medium thick cuttings, both treated and untreated with Radistim 2 gave the best results. Best rooting period, when rooting is effectuated in greenhouse, is from February to April, and it is 50 days. 2. Regarding the cuttings characteristics and rooting treatment influence upon the Ligustrum vulgare L. plants shoots growing in the first 5 weeks after transplantation into pots. The best results regarding the shoots growing was found at those plants which were obtained from thin cuttings of peak, and were treated with Radistim 2. The following best results were registered at the thick cuttings with 4 and 5 nodes and thin cuttings with 5 nodes treated with the rhyzogene substance. 3. Regarding the fertilization effect upon the Ligustrum vulgare L. plants growth and formation. The fertilization of Ligustrum vulgare L. plants, after the rooted cuttings plantation into pots, had a significant influence upon the plants formation, if Ferticare fertilizer is used, but also if Razormin fertilizer is used. The fertilization has a good influence upon the number of new shoots, the diameter and the height of the bush. A favorable effect upon the plants formation has also the duration of the fertilization, so the best growing indices were obtained when the fertilization was effectuated with Razormin for 15 weeks. 4. Regarding to Buxus sempervirens L. cuttings production. Buxus sempervirens L. cuttings rooted in a higher proportion when the substrates contained peat, compared to those where these were composed only from perlite or from a mixture of perlite + sand. This conclusion is according to the literature, where more authors recommend the substrates with peat for species with persistent leaves. The treatment of the cuttings with Radistim 2 had a more favorable effect upon the rooted cuttings in substrates without peat. The most unfavorable effect of the Radistim treatment upon the rooted cuttings was found at those substrates where no peat was used and it can be attributed to the fact that brown peat consist phytohormones (acetic acid-indolil) with rhyzogene effect (CRISTESCU şi colab., 1975). The culture substrate formed from perlite + peat or vermiculite + peat had a good influence upon the quality of Buxus sempervirens L. cuttings. The optimal substrates for Buxus sempervirens cuttings rooting (mixture of perlite or vermiculite with peat) have a reduced hygroscopicity coefficient ( ), a low wilting coefficient ( ) and an acid 19

9 chemical reaction (ph ) beside other characteristics of the peat, with high porosity, a high capacity of water retention and reduces salt content. 5. Regarding to the influence of the cutting type upon the Buxus sempervirens L. cuttings rooting. In less favorable conditions in those greenhouses where there are not modern amenities to ensure microclimate factors, and which are characterized by large fluctuation in temperature and air humidity, as well as relatively low temperatures in the rooting substrate at the beginning of the rooting process, the rooting percentage is in general very low. The peat alone is a less favorable substrate for the rooting of the Buxus sempervirens L. cuttings and this can be explained by its high capacity of retaining the water, often in the disadvantage of the substrate ventilation. Healed cuttings, in sand substrates: peat + sand (1:1) and perlite + sand (1:1) can ensure a higher quality for the rooting process, regarding the number and length of the roots. The sand, used in a proportion of 50% in mixtures with peat or perlite reduces much the costs of the used substrates for cuttings rooting. 6. Regarding the evolution of the growing and plants formation at Buxus sempervirens L. in the first two years after the rooting. Biometric studies on morphological characteristics of one and two year old plants revealed the species particularities and their usage as hedges and clipped forms: a slower growth in height and diameter, an increased ramification, reduced internodes and a higher number, weight and surface of the leaves. When plants reached the age of two years, the aerian parts weight doubled, the roots weight increased 5 times, and the surface of the leaves from a plant increased up to 2.25 times while the average surface of a leaf decreased from 0.90 to 0.68 cm 2. By providing a suitable plant density of 167/m 2 in first year and 111/m 2 in second year, the same foliar index of 2.18, can be realize, which provide, in comparison to other species, a good solar energy conversion in the process of Buxus sempervirens L. plants growing. 7. Regarding Taxus baccata L. cutting production. Taxus baccata L. cuttings rooted in a higher number in the substrate made from perlite + sand (1:1). In the substrates where peat was used these cuttings rooted in a lower number. Other authors considered that the substrates for conifer species must contain a high amount of sand and perlite and less peat (ILIESCU, 2005; DUMITRAŞCU, 2002; COPES, 1977). The quality of Taxus baccata L. rooted cuttings expressed by the number and length of the formed roots was 20

10 influenced by the composition of the substrate. The most favorable substrate for Taxus baccata cuttings rooting (sand + perlite) does not contain organic matter, it has a very high hygroscopicity coefficient (61.71%), a very high wilting coefficient (92.56%) and a neutral reaction (ph 7.20). The rooting period for Taxus baccata L. cuttings, in greenhouse, beginning with February, is 120 days. Recommendations For Ligustrum vulgare L. To obtain a higher percentage of rooting it is recommended the using of the peak cuttings, with a medium thickness and application of the rooting stimulator, Radistim 2, to obtain a higher quality, regarding the number of formed roots thick cuttings are recommended, to obtain in a shorter period a planting material for hedges and clipped forms, Ligustrum vulgare L. species is recommended (the rooting period being 50 days from the date of planting on parapets); to obtain rapid growths at this species it is recommended the usage of a complex fertilizer (Ferticare) and a foliar one (Razormin), best growing indices are obtained at the fertilization with Razormin for 15 weeks. For Buxus sempervirens L. To obtain a large number of rooted cuttings substrates containing peat are recommended. These substrates have a good influence on the quality of the cuttings (number of roots/cutting and the length of the roots). Using a mixture with sand 50% with perlite and peat reduces a lot the costs for rooting, using the rooting substance Radistim 2 at Buxus cuttings does not prove to have a high efficiency on the substrates which contained peat; ensuring a microclimate without excessive oscillations; cuttings with heals are recommended, at these were found higher percentages of rooting; Buxus sempervirens L. is recommended for hedges and clipped forms, because the slow growing rhythm, a good compactness given by short length of the internodes and high number of leaves. For Taxus baccata L. To obtain a high performance of Taxus baccata rooted cuttings it is recommended the utilization of a substrate formed from perlite + sand (1:1), while the substrates which consists peat are not recommended. Also, the treatment of the cuttings with Radistim 2 gives favorable results, leading to better rooting of cuttings and a higher degree of rooting. 21

11 LUCRĂRI ŞTIINŢIFICE PUBLICATE DIN TEMATICA TEZEI DE DOCTORAT 1. SABO GEORGETA, ADELINA DUMITRAŞ, D. ZAHARIA, V. SINGUREANU, G. MOLDOVAN, 2008, Coniferous species recommended for green fences in landscape design, Concepte, soluţii şi modalităţi de reducere a poluării mediului, ISBN , Ed. Napoca Star Cluj-Napoca, p SABO GEORGETA, 2008, Biological material propagation of buxus and ligustrum species used in green fences, Concepte soluţii şi modalităţi de reducere a poluării mediului, ISBN , Ed. Napoca Star, Cluj-Napoca, p SABO GEORGETA MINODORA, DUMITRU ZAHARIA, ADELINA DUMITRAŞ, V. SINGUREANU, A. ZAHARIA, 2008, Research regarding the propagation of some deciduous shrubs used for green fances, Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Seria Horticultură, vol. 65 (1-2), ISSN SABO GEORGETA MINODORA, 2010, Research regarding the influence of substratum and rooting regulators upon rooting capacity of Buxus sempervirens L. cuttings, Concepte, soluţii şi modalităţi de reducere a poluării mediului volumul II, ISBN , Ed. Todesco Cluj-Napoca, p SABO GEORGETA MINODORA, D. ZAHARIA, ADELINA DUMITRAŞ, DIONA CLAPA, I. ROŞCA, PĂUNIŢA POP (BOANCĂ), V. SINGUREANU, G. MOLDOVAN, 2010, The influence of substratum and rooting regulators upon rooting capacity of Taxus baccata L., Concepte, soluţii şi modalităţi de reducere a poluării mediului volumul II, ISBN , Ed. Todesco Cluj-Napoca, p SABO GEORGETA, DUMITRU ZAHARIA, ADELINA DUMITRAŞ, VALENTIN SINGUREANU, PĂUNIŢA POP (BOANCĂ), GELU MOLDOVAN, GEORGE MAZĂRE, 2010, Studiul unor cultivaruri de Buxus sempervirens în vederea utilizării lor în amenajarea spaţiilor verzi, Simpozionul ştiinţific internaţional Conservarea diversităţii plantelor, ISBN , Chişinău, p