Cultivos Tropicales, 2015, vol. 36, no. 1, pp. 103-110 January-March
ISSN print: 0258-5936 Ministry of Higher Education. Cuba ISSN online: 1819-4087 National Institute of Agricultural Sciences http://ediciones.inca.edu.cu
Review CULTIVATION OF THE DAHLIA Revisión bibliográfica El cultivo de la Dalia
Liudmila Jiménez Mariña)
ABSTRACT. The production and marketing of flowers RESUMEN. La producción y comercialización de flores and ornamental plants has been booming in recent years. y plantas ornamentales ha tenido gran auge en los últimos In Cuba, the cultivation of the dahlia is characterized by años. En Cuba, el cultivo de la dalia se caracteriza por variety of color, beauty and easy propagation. The aim of variedad de color, belleza y fácil propagación. El objetivo de this work was to present the characteristics and qualities as este trabajo fue dar a conocer las características y cualidades a cut flower. Addressed in the parameters related to their como flor de corte. En el se abordan parámetros relacionados origin, economic importance, botanical description, cultural a su origen, importancia económica, descripción botánica, practices, propagation and potting. We conclude that the labores culturales, propagación y cultivo en maceta. Se dahlia is a crop with great potential in Cuban floriculture concluye que la dalia es un cultivo con gran potencial en as it presents perennial and bushy growth habit, with petals la floricultura cubana ya que presenta hábitos perennes y intense lilac and easily spreadable by cuttings. crecimiento arbustivo, con capítulos lila intenso y fácilmente propagable por esquejes.
Key words: biotechnology methods, Palabras clave: métodos biotecnológicos, botanical description descripción botánica
INTRODUCTION costs; however, those possibilities The expansion of a number of are not exploited, so there are types, colors and sizes provides Cut flowers are about half the no flowers with higher quality. a strong possibility to increase market for horticultural products, Production volume and quality this production, which also allows where developed countries has improved; thus, today there offering superior qualities for are great prospects for achieving consume more than 90 %. Many certain periods. quality and volume, ensuring a consumer countries do not have In Cuba, it is of great interest ideal climatic conditions for solid production to appropriately supply the international market of to initiate the formation of a producing cut flowers, so that fresh flowers as well as to guide collection of dahlias that allows flowers grow under protected the steps towards developing their studying and selecting types and environments, thus production seed production so far depending forms adapted to the ecological prices increase (1). on imports (2). conditions, consumption habits In Cuba, production levels The cultivation of dahlia and production needs; this work of cut flowers still remain very (Dahlia spp.) is limited to Nivea must be done considering the low, supply does not match variety, which has become the existing form in the country, with demand and climatic conditions allow to obtain flowers all the basic species together with the rose perennial habits and bushy growth, year round with low production (Rosa sp.), gladiolus (Gladiolus intense lilac chapters and easily grandiflorus) and gerbera (Gerbera spreadable by cuttings. jamesonii Bolus L.), to match Consequently, the objective Instituto de Investigaciones Agropecuarias marketing requirements every of this paper is to present the "Jorge Dimitrov", km 16,5 carretera Manzanillo, Bayamo, Granma, Cuba, CP 85 100. season. Dahlia (Dahlia spp.) is characteristics and qualities of this ) [email protected] hardly known by consumers and crop as a cut flower. its production levels of cut flowers are low.
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ORIGIN AND beautiful flowers abroad; besides, The flower is essentially used SIGNIFICANCE OF DAHLIA it is the unique plant that has the in floral arrangements for the largest number of varieties among gift market. At present, there Dahlia genus is made up by 35 all plant species and more than are 41 international associations wild species that are endemic from 50,000 has been registered in concerned with the cultivation and Mexico; only four of them have the Royal Horticultural Society of spreading of dahlia; among them constituted the genetic basis for England (4). are the National Dahlia Society the development of its cultivation. The Mexican Association of in the UK, the American Dahlia With the Spanish conquest, dahlia Dalia (AMD) has reported that the Society (ADS), other groups of New was successfully introduced to main growing states are Mexico Zealand in European countries, Europe, starting in 1818 the City, Puebla and Mexico State. France and Germany (6). breeding studies that led to create Since 2007, the National Day of In Venezuela, this plant has inflorescences with diverse shapes Dahlia is celebrated in Mexico each been cultivated for more than and colors. Since that time up to August 4th (6). 60 years, mainly in the Center- now, four species have controlled West region and its culture was floral horticulture: D. coccinea, WORLD PRODUCTION basically used as cut flowers for D. pinnata, D. merckii and D. commemorative wreaths; however, imperialis. The most widely known SITUATION OF DAHLIA at present, the demand for dahlias is D. pinnata, which is derived The international trade of (types: casual decorative, round from a fertile hybrid between D. cut flowers is worth about 11,000 and semi-cactus) has increased coccinea and D. sorensenii likely million Euros, which gives an idea to decorate gardens and parks (7). produced in Mexico about 500 of the economic importance of this In Cuba, the development of years ago (1). activityA. floriculture is related to the rise Dahlia is native from the clay- Concerning its bulb production, of sugar industry, as a result of siliceous highlands of Mexico, Holland takes the lead with 400 ha, introducing species and varieties although many species have followed by France and Chile with by settlers, ranchers and owners been found in South America and 40 ha and 7.3 ha respectivelyB. of mills, with the aim to brighten Central America (3). Taking into account its beauty, the environment surrounded by Different species of dahlia dahlia is such a flower that has cane sugar. By the middle of comprise several ranges of acquired a similar ornamental the nineteenth century arose variation, from those geographically importance to the Dutch tulip in in Havana the first commercial very restricted up to the ones that Europe. However, few people gardens, mainly devoted to grow appear in a wide range of variation, know it is from Mexico and it is not roses and ornamental plants. In between 200 m and more than really a flower but an inflorescence 1914, the first dahlia tubers were 500 m over sea level; and other (composed by two types of small introduced from the United States. cases, such as D. australis, which flowers), also its ancestors are still At present, the consumption of is distributed into geographically admired in Mexico City (1). flowers and ornamental plants isolated regions, comprising a In the decade of 1820-1830, has increased; however, this rate height range of 1500-2500 m over dahlias were in fashion and is still low, as only small areas are sea level (4). their prices rose considerably. devoted to this crop, mainly by C The name "Dahlia" was given Specialists cataloged them as small growers . by the botanist Andreas Dahl. a "decorative flower". Everyone Regarding the cultivation of dahlia (Dahlia spp.), so far, most In Belgium, the first ornamental wanted dahlias in their garden. studies has been related to the plants obtained had large, double So much successful it was (3) flowers, which quickly spread dynamics of biomass accumulation that it began to overshadow the and extraction of nitrogen, throughout the continent and were chrysanthemum (a favorite flower); phosphorus and potassium; preferred by the court of Queen thus, a series of exhibitions was assessment of postharvest flower Victoria (1). organized in parallel with the latter. conservation and behavior of Conversely, for two centuries postharvest flowers during shelf life. of cultivation, selection and hybridization have made it an CFernández, Alicia ; Marrero Virginia; A Claps, L. Perfil del mercado mundial de bulbos ornamental species that offers Salgado, Julia; Cruz, Mercedes; Igarza, A; para flor. [Informe preliminar]. UEM INTA, Hernández, Maria I; Calzada, V y Rajme, Yamir. greater diversity of sizes, shapes Santa Cruz, 2001. and colorful flowers (5). Recomendaciones técnicas para la producción B Traub Ramos, Alfonso y Vicuña Herrera, y comercialización de flores de corte. [Informe This cut flower has very Bárbara. Flores de cortes: nuevas oportunidades. final de proyecto]. Instituto de Investigaciones particular characteristics, so that Oficinas de estudios y políticas agrarias- Odepa. Hortícolas “Liliana Dimitrova”, La Habana. it has become into one of the most Ministerio de la Agricultura. Chile. 2012. 13 pp. 2008. 21 pp.
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On the other hand, directed only to sunlight, but dense, ♦ Family: Asteraceae recommendations have been made with a large number of leaves (9). ♦ Sub-family: Asteroideae on N doses, N/K relationships Inflorescence is presented ♦ Tribe: Coriopsideae and its division, besides defining by large heterogamous heads, ♦ Genus: Dahlia maximum growth and macro sometimes mid-sized, isolated ♦ Species: 30 species, 20 000 nutrient (N, P, K) consumption or irregularly headed on long varieties times. and naked stalks, with beveled, These results constitute the bell-shaped and hemispheric CLASSIFICATION first reports on the studies related to involvement (3). growing technologies of cut flowers The small heads are radiated The specific name adopted, in Cuba, particularly those referring and have 15 cm diameter, raised Dahlia variabilis (octaploid hybrid: to the methodologies for obtaining or inclined, with very variable ray 2n= 64) indicates its characteristic seeds as well as production under flowers light purple, yellow or of spontaneously producing new protected conditions (8). pink at its basis. Disc flowers are forms, as well as its ability to sometimes replaced by fertile or interbreed and hybridize, which BOTANICAL DESCRIPTION sterile ray ones (9). It has been have led to a number of types, also stated that flowers are usually forms and hybrids that impede their Dahlia belongs to peripheral, uniserial, ligular, sterile, botanical classification (6). Asteraceae family and its white or purple, yellow or red, as At present, there are about two main species are Dahlia well as fertile hermaphrodite disc, 20,000 varieties recognized by pinnata Cav. and D. coccinea yellow or purple (6). the International Registration of Cav (1). Among the 27 species Inflorescence may be single Dahlias (5). According to its chapter comprising the genus, the best with an outer red ring of bright characteristics and plant habit, known are D.coccinea, D. merckii, flowers surrounding a central which determine its application D. pinnata, D. imperialis and D. disc of smaller and double yellow to gardening or as cut flower, variabilis (3). flowers predominating the colored dahlia has been classified by the It is a vigorous, perennial and ones (5). American Dahlia Society, as: ''sometimes'' little woody plant, The fruit is a linear oblanceolate Curved cactus flower: double- some epiphytic or climbing species or sometimes broadly spatulated flowered varieties with rolled (5); herbaceous with fleshy roots achene or it consisting of two dewlaps bent towards the chapter (tubers). The roots grow during small rudimentary or sometimes center. a developing stage, so that after conspicuous and often outdated Upright cactus flower: double- completing its cycle and when ones (3). It has very different flowered varieties with upright the vegetative organs (stems and forms depending on the species dewlaps in the chapter. leaves) are dying, they start a or variety; it is constituted by a Semi-cactus: double flowers with dormant period (latency) of 60 or variable number of squamous less rolled dewlaps than in the two 90 days, after which canopy buds head-forming bracts wrapping previous types. are activated and produce new seeds; in chapters, very double Peony flower: double large flowers shoots (9); then, a tuberous root seeds are often limited, monstrous of irregular and curly petals leaving develops to be used for vegetative and usually sterile (9). the flower center visible; ray flowers propagation (4). The dahlia is a medium are arranged to communicate to The inner and outer stem strength flower, which has a wide peony flower chapter. structures lack of nodes and popularity in Cuba, mostly used in Decorative flower: double-flowered internodes, the buds are only floral arrangements. However, its varieties with regularly arranged presented at the end of the production on a significant scale is dewlaps in concentric line with its proximal stem or canopy and form limited to semi-cactus white Nivea acuminate end. It has every color. fibrous roots only at the distal end variety. Examples: "Napoli" and "Cream" of the stem or canopy. They have a (dark salmon), "Peau Rouge '(red). reverse polarity to that of a normal TAXONOMIC LOCATION Irregular decorative flower: tuber (5). chapters have much more Dahlia has triangular leaves of ♦ Kingdom: Plantae irregularly arranged dewlaps than denticulate margin and unifoliate ♦ Sub-kingdom: Tracheobionta the previous type. nervure. Foliage is pale green and ♦ Division: Magnoliophyta Flower in ball: its crop is limited; lacks a special bright. This plant ♦ Class: Magnoliopsida very double, firm, nearly spherical can have different sizes, from 30 ♦ Sub-class: Asteridae chapters. Globe-shaped flowers cm to more than 1,2 m high; also, ♦ Order: Asterales and cylindrically rolled round it develops a messy branching
105 Cultivos Tropicales, 2015, vol. 36, no. 1, pp. 103-110 January-March petals, upright stems reaching prepared at the beginning of dry It has been pointed out that up to 1.50 m high and profusely or poorly rainy season to reduce there are some varieties with blooming. adverse factors characteristic low rooting capacity whereas Anemone flower: its chapters of the rainy season, such as others with quick capacity (5). In resemble the flowers of that high temperature, low rainfall and another study it was indicated that relative humidity (9). Seeding ornamental species. such capacity increase may be bottom should be ready at the Single flower: chapters are not beginning of germination by mixing greater when growth is inhibited, doubled; flowers have long petals one part of plain soil and one part by removing all vegetative parts and different colors; it is used in of river sand. that are growing, also the inhibitory garden borders and in groups on Sowing should be done in activity is higher in hardly rooting the grass. such a way that seeds are only reproductive cuttings than in easily Double flowers: not very stuffed covered by a mixture layer of rooting vegetative cuttings. double chapters that do not present 2 to 3 mm, and then a slight Original plant sprouting should defined typical shapes. irrigation is applied to prevent the be separated from the main tubers Collar flowers: chapters with a subsequent drying of the layer from February to April. First, in medium dewlap circle around the where seeds are; the container January-February, tubers are put disc, shorter than radial dewlaps or seedbed will be protected with on hot beds at 15-20 °C using a and of a different color. guano, cheese cloth or straw. If substrate made of equal parts of Liliput flowers: very small spherical seedbed is properly managed and peat and sand. Cuttings of 5 to 10 chapters with short or serrated the seed has the required fertility, cm are taken out from the mother (honeycomb) dewlaps. Ex: ''Atoll'' germination must start at the 8th or tuber with a disinfected knife. They (red). 10th days, although it may take up are placed in trays or pots with a Thumbnail flowers: chapters are to 21 days (3). quite rich soil mixture (improved equal in shape and arrangement Once small plants reach 5-7 cm peat) at 18 °C. They are regularly to decorative ones, but very small. high, they are transplanted to watered as rain, so the soil is kept transient beds (nurseries), where moist. Rooting takes place in two SEXUAL AND ASEXUAL they will remain until they have to three weeks (20-60 cuttings per tuber in two or three months). PROPAGATION four leaves, then at this time they are transferred to containers or a Planting takes place from June The most widely used new nursery until reaching about to mid-July for obtaining medium methods for its propagation are via 20 or 22 cm high and transplanted sized tubers. Cuttings are planted cuttings or tuberous root division to the definite field, where they are in the rooting medium, burying them (3); however, the most commonly given the same cultural attention 1/3 long in rows 7-8 cm apart and used is the commercial form by as plants derived from cuttings, about 4 or 5 cm of others; from 240 cuttingsD. with only one difference that they to 300 cuttings per square meter Seed: seed method is employed are not subjected to desuckering will be planted at these distances. to obtain new varieties (1).When to get a more vigorous growth and Rooting starts when there is a color seeds are sown in the soil, an earlier flowering (9). change from pale to intense green germination lasts up to a month; Cuttings: its production consists and terminal bud growth ends (9). however, when they are put in filter of placing tuberous roots in a Once root system is developed papers at Petri dishes, it only takes humid substrate to rapidly induce (5), cuttings are transplanted to three days. Seed germination is sprouting; then sprouts are cut and beds at 50 cm apart an d a r o w associated to the highest levels of placed in pots to be rooted (3). spacing of 90 cm. This oxygen, because it has an internal In May, they can be definitely density and late planting date impervious membrane to oxygenE. transplanted to plain soil leaving restrict tuber development or In Cuba, seedbed should be about 80 cm between them. They thickening (minimum standards: 40 g usually bloom the same year. for decorative dahlias). In November, plants should be Tuber division: This is the most commonly used form or method DSeeman, P. y Andrade, N. Cultivo y manejo de removed and tubers kept in a dry plantas bulbosas y ornamentales. Universidad room (5). of propagation in Cuba, due Austral de Chile. Facultad de Ciencias Agrarias. On the other hand, to better to material stability, and plants Instituto de Producción y Sanidad Vegetal, induce branching, the central stem derived from tubers show an earlier 1999. 218 pp. blooming than those obtained by E end should be cut in spring; later, Arroy L., E. N. Tamaño, forma y vigor de other methods (9); multiplication germinación en semilla de dalia. [Tesis de when stems have reached 10 to Licenciatura]. Universidad Autónoma Popular 12 cm, a stem is separated and a by tuber division is the simplest and del Estado de Puebla, Puebla, Méx.1991. easiest way to practice and has the pp. 6-11. rooting is applied to it (3). advantage that plants get vigor (5).
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Tuberous root division consists Over 50 years ago, Morel and of plant growth regulators. In of crown division, so that each Martin reported the regeneration of medium A (NAA and BAP) was section carries a stalk bud. The free-of-virus plants by excision and used whereas in medium B (IAA procedure for this method begins meristematic dome apex culture and BAP). Callus induction and by extracting intact tuberous roots of infected plants; then, the best shoot regeneration was directly from the soil at the beginning of dry result was reached by a Knop proportional, while root formation season and drying them a few days solution medium half diluted with was inversely proportional to before storing. Storage takes place 2 % glucose and 0.5 mg L-1 Difco the addiction of different growth at 2 to 10 oC, where roots are put yeast extract, achieving 1-mm- regulators. Top values for callus on a bed of sawdust or vermiculite, high plants without rooting. In induction and shoot regeneration preventing to be exposed, because general, this discovery encouraged were recorded in a medium they become wrinkle (3). intensive cultivation (10). with 3 mg L-1 NAA and BAP. The plant is provided with a However, apical meristems Regeneration could be useful for a number of underground tubers, were also usedF on a Murashige mass material propagation and to each one with its corresponding and Skoog medium (11) at different enhance ornamental plant diversity bud on the fleshy part, otherwise combinations of IAA and BAP. The (15, 16). reproduction would be impossible. best combination was 1 mg L-1 Studies have been done Rhizome division should be done IAA with 1 mg L-1 BAP to obtain on accelerated reproduction, at the same time of planting. It sprouting. evaluating five media, four accepts all non-calcareous soils Consequently, a study was regeneration media, four rooting with pH around 7, enriched with performed to carry out a process media and four growing substrates very rotted manure and avoiding for its propagation from flower and concluding the best stem excess nitrogen that causes a very buds and stem apices, growing on and shoot inducing medium was significant foliage development a Murashige and Skoog medium MS+BA+NAA, the generating at the expense of tuber growth; (11) with IAA (0, 0,05 and 0,1 mg L-1) medium was MS+BA+NAA+B, and basal dressing must be of 100 kg ha-1 +BAP (0, 0,05, 0,1, 0.2 mg L-1). rooting medium was ½ MS+NAA, -1 P2O5 and 200 kg ha K2O whereas Shoot rooting can be done in a growth substrates being pine+sand maintenance application of 50 kg ha-1 medium with IAA (0,5 mg L-1) or needles (17). N in June, July and August; there even without auxin in the culture A good micro-propagation should be plenty regular irrigation (9). medium; however, evidently, there protocol could be useful for The ethylene present in plants is variation in shoot rooting ability. plant material production. Plant (3) increases within short days, Cultured apices in presence of regeneration has also been directly marking a quick change between BAP yielded reddish pigmented reported from explants without callus formation or indirectly through tuber bearing period and apex shoots (12). callus induction and regeneration. growth cessation; thus, ethylene Some has noted that in vitro There are few available reports on may be involved in its tuber culture shoot rooting may be in vitro propagation of Dahlia spp. initiation or induction. directly made in a mist chamber However, in other flower cultures In vitro culture: it is the best choice, (13). Others studied the effects like carnation and gerbera, indirect because it is a quick and reliable of cytokinins (BA and zeatin) as regeneration was reported from method (2). well as sampling time of primary explants as apical meristems (18), Because of its wide genetic explants. The highest regeneration floral buds and hypocotyl (19) in variability present in various rate of primary explants was different media and stems as well wild species, tissue culture observed (14) when explants were as root regeneration took place in could guarantee asexual clonal cultured on a Murashige and Skoog the callus (10). multiplication of individuals with medium with 0,5 mg L-1 zeatin. Thus, in vitro propagation in outstanding genetic characteristics Dahlia Mosaic Virus (DMV) can the world plays an important role, and would allow more efficient and be removed from infected plants since it enables to obtain large reliable crossing schemesF. by meristem culture. Meristem quantities of plants using little culture efficiency in removing material and plants will present the DMV was 50 % whereas 9 % for same characteristics as the one G (2). the plants growing from meristem that gave origin to it sizes 0,4-0,5 mm and 0,9-1 mm, FFernández, C.; Hernández, P.; Becerra, L. GFonseca, D. Establecimiento y multiplicación in Propagación de meristemos apicales de respectively. Cotyledon leaves and vitro del clavel español (Dianthus caryophyllus) dalia (Dahlia spp) in vitro (ensayo). [Tesis con el empleo de algunos reguladores del de Licenciatura]. Universidad Popular hypocotyl explants have also crecimiento. [Tesis de Diploma]. Facultad de Autónoma del Estado de Puebla, Puebla, been used on a MS medium Ciencias Agrícolas, Universidad de Granma, México.1990. 92 pp. supplemented with combinations Cuba. 2007, 85 pp.
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EDAPHOCLIMATIC of lateral branches and when they Control: Treatments with systemic REQUIREMENTS reach 6 inches (15 cm), they are insecticides at the onset of cut into cuttings and treated as attacks. Referring to soils, dahlia is a previously explained (5). Cuttings - Thrips (Frankliniella rustic plant, although it prefers plain or stakes should have two or three occidentalis). Direct damages soils with perfect drainage and pH knots without leaves (9). are caused by larvae and adults between 6 and 8, with a high content ♦♦ Disbudding when feeding, especially on leaf of organic matter and nutrients (9). Flower production of good underneath and inside flowers. Excessive N fertilization weakens size and quality for cutting (good One way to detect them is by its stems, overdevelops leaves size and long stem) requires shaking any flower on the back and damages flower preservation. flowering control and guide by of the hand. Phosphorus and potassium make removing buttons and secondary Control: Treatments with systemic stems rigid, emphasize flower buds located in the axils of the insecticides at the onset of color and activate tuber maturity. two pairs of leaves, which are attacks. Potassium invigorates the plant immediately under the apical and encourages tuber reserve button; this activity must be done - Lepidopteran caterpillars formation. It was also found that before such sprouts reach 5 cm, (Spodoptera exigua, coastal magnesium sulphate has particular when tissues are still tender (3). Spodoptera, Heliothis armigera, impact in bloom (3). Their remotion will let obtain a main Autographa gamma, etc). Dahlia prefers temperatures flower with stalks reaching 60 to 70 Damages are caused by larvae between 18 and 23 °C, relative cm long (5). when feeding on leaves and humidity of 75 to 78 % (5), high ♦♦ Desuckering fruits. Adults are nocturnal rainfall from 11 to 13 hours and It consists of removing a moths that do nothing. little wind action (9). high number of shoots or sprouts Control: Treatments with systemic This plant grows in sunny in tubers, allowing only the insecticides at the onset of areas; however, it can also be development of two or three of attacks and removing weeds. cultivated in semi-shade (5). The the most vigorous ones, ensuring ♦♦ Diseases leaf characteristics, its wide surface shapely and vigorous plants to - White Coal (Entyloma dahliae). as well as weak stem constitution yield flowers with good size, shape It causes circular spots (up to 1 demand to be duly cultivated in and stem length (9). If all shoots are cm diameter) on round, elliptical protected areas from the abrasive allowed to grow, flower production or angular leaves. Spots change wind action, which can raise is greater in number, but of lower color from pale to brown when transpiration up to inconvenient quality (3). ripe. levels and also seriously give - Wilt (Fusarium sp.): The affected mechanical damage to plantation PESTS AND DISEASES plant cannot develop very well, (3) .Other authors state that it must it losses quality and dies. Its be watered after planting, but no ♦♦ Pests symptoms start by changing more irrigation is applied until - Aphid (Myzus persicae). The older leaf color. Its inner tissues sprouts do not appear unless there nymphs and adults suck sap, turn reddish coffee; this damage is a dry period, then when leaves causing leaf yellowing and plant extends towards plant top. develop large surfaces, irrigation weakening. Also, it produces Control: Use healthy plant material, increases (1). molasses on which the black remove all infected plants and fungus stays. reduce irrigation. CULTURAL PRACTICES Control: Treatments with systemic insecticides at the onset of ♦♦ Staking attacks. BACTERIOSIS It may be performed at two - Whitefly (Trialeurodes different times: before or at planting, There is bacteriosis as vaporariorum and Bemisia as explained above, or when plants Agrobacterium tumefaciens that tabaci). Direct damages are have reached sufficient height (25 swells tubers; Corynebacterium yellowing and plant weakening to 30 cm) to do the first tie (9). fascinas that makes galls on leaves caused by larvae and adults ♦♦ Tipping or disbudding and Erwinia chrysanthemi that when feeding, sucking sap from It should be performed when leads to tuber rot. leaves. Indirect damages, as in new plants reach about 25 cm high, Control: Discard affected plants, aphids, are due to black fungus then the apical bud is removed, disinfect work tools and hands after proliferation on bold molasses which promotes the development handling diseased plants and keep produced by whiteflies. foliage dry to avoid further injuries.
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POT CULTIVATION Others applied concentrations balanced mixture of 2:1:2. The light -1 OF DAHLIA of 0, 50, 100, 200 and 400 mL L should be high, between 30,000 paclobutrazol to Dahlia pinnata and 50,000 lux, to prevent an Potted dahlias can be obtained Cav plants every 14 days (21). excessive rise in temperature (5). with dwarf varieties grown from After seven dosages, the best seeds or vegetatively-propagated response was observed with CONCLUSIONS tubers after reducing its size by 400 mL L-1, obtaining 45,30 cm means of growth retardants (5). high plants with short internodes, In Cuba, the cultivation of Research on the application higher chlorophyll content as well dahlia can be an important choice of phytoregulators included as increased weight and volume for the ornamental plant marketing, three types (Agromyl V, TF of tuberous roots, compared to as it has been poorly studied and Biozyme, Nettle and control). the control. most growers are ignorant about Three applications of each Several studies related to the it. Thus, it is evident the need to phytoregulators were performed, effect of different growth media apply biotechnological methods whereas the manufacturer's on the development of Dahlia in for its rapid spread and obtain recommended dose was applied pots have been carried out (17): new varieties and crop technology, to commercial types, and Nettle at sand, silt, leaf mold, silt+sand, which allows to make up a collection 20 g fresh weight per liter of water. sand+leaf mold, silt+leaf mold of dahlias adapted to the ecological Different doses were prepared and sand+silt+leaf mold. The conditions, consumption habits and applied to leaves. The natural best medium was sand+silt+leaf and production demands. breeder based on Nettle (Urtica mold for almost all parameters dioica) showed greater height, with evaluated: plant height (42,08 cm), BIBLIOGRAPHY a value of 6 cm over 30 days which stem diameter (1,93 cm), number surpassed TF Biozyme growth of of branches per plant (4) minimum 1. Mera Ovando, Luz M. La 5 cm and Agromyl V growth of days to flowering (92), number of dalia una belleza originaria 4 cm. Chemical phytoregulators flowers per plant (11), number of de México. Revista Digital increased leaf area and presented petals per flower, flower diameter Universitaria, 2006, vol. 7, no. 11. a larger bud numberH. (8,8 cm) and vase life duration ISSN 1067- 6079. Also, other studies have been (five days). The medium composed 2. Hernández, L. El cultivo del conducted on height reduction Anthurium. Cultivos Tropicales, of leaf mold alone also did it well 2004, vol. 25, no. 4, pp. 41-59. according to forms of application with all parameters, including a (foliar and substrate), frequency ISSN 1819-4087. maximum of 42 leaves per plant. 3. INFOAGRO. El cultivo de la dalia (all in one application or two) and The sand, when used alone as [en línea]. 2009. [Consultado: rate (three doses and a control) a growing medium recorded the 14/12/2009]. Disponible en: with Unicozole-p (Sumagic). Both
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8. Curbelo, J. Renacen los jardines 14. Sediva, J.; Novak, J. y 18. Can, C. y Koc, N. K. Investigation [en línea]. Edición Digital. La Kanhka, J. Micropropagation, on in vitro micropropagation Habana, Cuba: Editora Zoe detection and elimination of of Carnation (Dianthus sp.). Beato Morejón, 27/2/2007. DMV in the czech colletion Turkish Journal of Geriatrics, [Consultado:6/3/2008] of dalia. En: V International 1994, vol. 16, pp. 641-648. Disponible en:
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