Phenology of Daffodils varieties in the Mari El Republic conditions

Okach Mariya Aleksandrovna Teacher at the Department of Garden and Park Design, Botany and Dendrology of Volga State University of Technology 424030, Russia, Mari El Republic, Yoshkar-Ola, Lenin Square, 3, aud. 245 OkachMA@volgatech.net Other publications by this author     Mukhametova Svetlana Valeryevna ORCID: 0000-0001-7892-6450 PhD in Agriculture Associate Professor at the Department of Garden and Park Design, Botany and Dendrology of Volga State University of Technology 424000, Russia, Mari El Republic, Yoshkar-Ola, Lenin Square, 3, aud. 245 MuhametovaSV@volgatech.net Other publications by this author

Egoshina Evgeniya Alekseevna Student, Department of Landscape Gardening, Botany and Dendrology, Volga State University of Technology 424000, Russia, Republic of Mari El, Yoshkar-Ola, Lenin Square, 3, room 245 egoshina_ev@bk.ru

Introduction. Daffodils are perennial bulbous plants belonging to the genus narcissus (Narcissus L.) of the Amaryllis family (Amaryllidaceae Jaume). The genus contains about 60 species, found mainly in the south of Western Europe. Modern varieties of daffodils are complex multi–stage hybrids united under the common name N. ? hybrids hort., many of which are polyploids with large flowers. The morphological structure of daffodil flowers is very diverse. On this basis, the varieties of the International Register, of which there are more than 30 thousand, are divided into 12 garden groups ^[1].

Daffodils are characterized by plasticity and comparative undemanding to growing conditions, decorative, abundant flowering ^[2], pleasant aroma and original flower shape. The perianth is actinomorphic and consists of 6 bent free lobes (bend) and a privenchik formed by fused outgrowths of lobes (crown). The crown has a tubular, bell-shaped or cup-shaped shape, can be whole or dissected, the number of crown segments can increase and give the flower a terry ^[3]. Daffodils are universal when possible to use. They are irreplaceable in gardening, give excellent cutting material, suitable for winter distillation. According to the scale of cultivation, daffodils belong to the three leading cultures of the world along with roses and chrysanthemums ^[4]. When growing, daffodils are responsive to such agrotechnical measures as mulching ^[5], double fertilization with nitrogen ^[6], introduction of biofertilizers into the soil, foliar fertilization with potassium ^[7], treatment with growth stimulants, for example, gibberellic and humic acid ^[8]. Daffodils are susceptible to viral infections, which lead to a decrease in the size of bulbs and their number, a decrease in the quality of flowering ^[9]. The leaves remain active after flowering, and their early removal reduces the yield of bulbs. For most varieties, it is recommended to dig out bulbs six weeks after flowering ^[10].

The timing of the onset of the phenological phases of daffodils and their duration depend on varietal characteristics, as well as on the weather conditions of the growing season and may fluctuate in one direction or another ^[11].

The purpose of this study was to study the seasonal development of Narcissus varieties in the conditions of the Republic of Mari El.

The objects of the study were plants of 6 varieties of the collection of the Botanical Garden-Institute of the Volga State Technological University (Yoshkar-Ola, Mari El Republic): 'Carnmoon', 'Duke of Windsor', 'Odense', 'Texas', 'White Lady', 'Yellow Cheerfulness'. These varieties belong to the group of small-borned, large-borned and terry.

Large-borned daffodils are characterized by the large size of the crown of flowers: the crown height is shorter than the perianth lobes, but not less than 1/3 of their length. This is the most numerous and popular group in the whole world. They are obtained as a result of crossing tubular and poetic daffodils and are distinguished by a variety of shapes and colors of crowns ^[12]. Small-horned daffodils are created as a result of reverse crosses of large-horned daffodils with Narcissus poeticus. The crowns of the flowers of these daffodils do not exceed a third of the length of the perianth lobes (bend). These are quite tall plants with one medium-sized flower, they are unpretentious to the growing conditions. They bloom a little later than varieties of other garden groups, thereby prolonging the flowering period of daffodils. Abroad, they are widely used in various types of green spaces, grown on a cut and driven out in winter ^[1]. Terry daffodils are spontaneous hybrids or somatic mutants of tubular, large-borned, small-borned and other daffodils, therefore their flowers have different morphological structure ^[11].

'Carnmoon' ('Karnmun') belongs to the group of small-crowned. Originator Guy L. Wilson, 1953, Northern Ireland. The flower is up to 8.5 cm in diameter, pleasantly fragrant. The perianth lobes are white, oval, the outer ones have a sharply prominent beak. The crown is cup-shaped, corrugated, 1.2 cm high, 2.7 cm in diameter, cream, with a brownish border along the wavy edge (Figure 1). Plant height up to 40 cm . The variety is suitable for group planting, cutting, distillation ^[13].

Figure 1 – Flowering of 'Carnmoon' (photo by M.A. Okach) 

'Duke of Windsor' ('Duke of Windsor') from the group of large-horned. Originator G.A. Uit den Boogaard, 1937, Holland. The flower is up to 10 cm in diameter, fragrant. The perianth lobes are white, the outer ones are oval, the inner ones are ovoid, slightly bent towards the peduncle. The crown is saucer-shaped, 1.7 cm high, 4.8 cm in diameter, orange-red. The edge of the crown is dissected into large blades that overlap each other (Figure 2). Plant height up to 42 cm . The variety is suitable for group planting, cutting, distillation ^[13].

Figure 2 – Flowering of 'Duke of Windsor' (photo by M.A. Okach)

'Odense' ('Odense') is included in the group of large-horned. Originator Konynenburg and Mark, 1960, Holland. The flower is up to 9 cm in diameter, has a pleasant aroma. The perianth lobes are white, rounded, well overlapping. The crown is funnel-shaped, 2.4 cm high, 4.3 cm in diameter, light yellow with a greenish tinge, longitudinal stripes are noticeable from the middle of the crown, which form a clear intermittent, yellow-orange border 1.2 cm wide closer to the edge. In some places, the crown is dissected almost to half (Figure 3). Plant height up to 40 cm . The variety is suitable for group planting, cutting, distillation ^[13].

Figure 3 – Flowering of 'Odense' (photo by M.A. Okach)

'Texas' ('Texas') belongs to the terry group. The originator is Mrs. R.O. Backhouse, 1928, England. The flower is up to 10 cm in diameter, almost fragrance-free, thick-browed. The perianth lobes are yellow, oval. Between them are the orange lobes of the crown, the most crowded in the center of the flower (Figure 4). Plant height up to 27 cm . The variety is suitable for group planting, cutting, is strongly affected by the virus ^[13]. It belongs to a subgroup isolated from the group of large-bordered varieties. The double color of the flowers is formed by increasing the number of perianth lobes and crown segments, the crown in the flowers is preserved ^[11].

Figure 4 – Flowering of 'Texas' (photo by M.A. Okach)

'White Lady' ('White Lady') from the group of small-crowned. The originator of the Rev. Geo. H. Engleheart, 1898, England. The flower is up to 7.0 cm in diameter, pleasantly fragrant. The perianth lobes are white, lanceolate, slightly raised to the center of the flower. The crown is cup-shaped, 1.7 cm high, 2.2 cm in diameter, light yellow, bleached during flowering. The edge of the crown is folded-lobed. Plant height up to 35.0 cm . The variety is suitable for group plantings ^[13]. It is a historical variety ^[1].

'Yellow Cheerfulness' ('Yellow Cheerfulness') is part of the terry group.  The originator of Sport from Cheerfulness, 1938. Flowers with a strong, pleasant aroma, up to 4.5 cm in diameter, 3-4 on the peduncle. The perianth lobes are lemon-yellow, rounded. The crown is cup-shaped, 0.4 cm high and 1.5 cm in diameter, lemon-yellow. Inside the crown there are additional segments that give it a terry (Figure 5). Plant height up to 37 cm . The variety is suitable for group planting, cutting, distillation ^[13]. It is part of the subgroup of terry narcissus mutants of the group of tacetes. Flowers collected in inflorescences of 3-5 pieces ^[11].

Figure 5 – Flowering of 'Yellow Cheerfulness' (photo by M.A. Okach)

Research methodology. Phenological observations were carried out for 6 years from 2014 to 2019 according to the methodology of the Main Botanical Garden of the Russian Academy of Sciences ^[14]. Calendar dates have been converted to a continuous numerical series since March 1. The observation results were processed using the Microsoft Excel software package at a 95% significance level ^[15]. All varieties are distributed according to the xsr criterion.±? for early, medium and late phenophases under study.

Results and discussion. The results of phenological observations of plant leaves are given in Table 1.

Table 1 – Average long-term phenodates of leaf development

The beginning of vegetation (spring regrowth) in most varieties on average occurred in mid-April. Only in the terry variety 'Yellow Cheerfulness' late regrowth was noted (23.IV). In the conditions of Minsk ^[11], this variety is also characterized by late regrowth.

The phase of mass deployment of leaves occurred 10-12 days after the start of regrowth, but in the 'Carnmoon' variety – after 16 days, in early May, simultaneously with 'Yellow Cheerfulness'. These 2 varieties are assigned to the group of late ones according to this phenophase. Large–borned daffodils 'Duke of Windsor' and 'Odense' were characterized by the early end of leaf growth, at the beginning of the second decade of May, and terry 'Yellow Cheerfulness' - late, at the end of the second decade of May. The last named variety has also been found to have late leaf death (10.VI ). Thus, the long duration of vegetation was characterized by the variety 'White Lady' (56 days), a long period of leaf growth – terry 'Texas', small-crowned 'Carnmoon' and 'White Lady' (30 days). The short duration of vegetation and the period of leaf growth was distinguished by 'Yellow Cheerfulness' (48 and 25 days. respectively).

The results of observations of generative shoots of plants are shown in Table 2.

Table 2 – Average long-term phenodates of generative organs development

The early appearance of buds was noted in 'Odense' (on average 28.IV), later – in 'Yellow Cheerfulness' (10.V). The same varieties are classified as early and late in the beginning and mass flowering. At a late date, the flowering of the plants 'White Lady' and 'Yellow Cheerfulness' (31.V) was completed. The flowering dates of the studied narcissus varieties cover on average the period from May 5 to May 31. Thus, one of the small–borned varieties 'Carnmoon' was characterized by a short flowering duration (12 days), and the second, 'White Lady', on the contrary, by a long flowering duration (19 days). The remaining varieties had an average flowering duration. The variety of flowering dates of small-crowned daffodils has been noted in the works of other authors ^[4].

In the conditions of Minsk ^[11], the terry multi-flowered variety 'Yellow Cheerfulness' is also characterized by a consistently late flowering period, which is consistent with the data we obtained. The small-borned variety 'White Lady', on the contrary, in the conditions of Minsk ^[1] has an early flowering, although in the conditions of Yoshkar–Ola it is late and prolonged. In general, daffodil varieties bloom on later calendar dates than in Belarus ^[13].

The studied daffodils were characterized by a relatively friendly passage of phases of seasonal development. The interport variability of average phenodates is weak and moderate, only significant in terms of flowering duration (15.9%). The lowest variability between varieties is in the phase of complete leaf death (1.3%).

Correlation analysis revealed a very close inverse relationship between the beginning of vegetation and its duration (r=-0.94), that is, varieties that started vegetation later vegetated longer. The timing of the beginning and mass flowering was closely correlated with the timing of budding and complete leaf death (r=0.91...0.97). The duration of leaf growth was closely correlated with the duration of vegetation (r=0.82). The correlation matrix is shown in Table 3.

Table 3 – Matrix of coefficients of paired correlation of phases of seasonal development of narcissus varieties

 Note: bold straight font is a very close connection, bold italics is a close connection.

During the observation years, the shortest flowering of daffodils was recorded in 2015 and 2019, and in 2015, plants of the varieties 'Yellow Cheerfulness' and 'White Lady' did not bloom. The earliest beginning of the growing season and its late end were marked in 2014, the late beginning and early end – in 2018 and 2019. These differences are not entirely consistent with the dates of stable transitions through temperature limits ^[16]. Probably, the seasonal development of daffodils depends on other indicators, such as soil temperature, average daily air temperature, maximum air temperature. So, in the conditions of Minsk ^[11], the beginning of flowering of daffodils occurs when the soil is warmed up to 10-12 ° C, and the air – 13-15 ° C. This assumption should be verified in the following studies.

Conclusion. Thus, of the 6 varieties of narcissus belonging to three groups, the terry multi-flowered variety 'Yellow Cheerfulness' was distinguished by the late passage of all the studied phenophases, as well as the shortest duration of vegetation and growth. The large-borned variety 'Odense' was characterized by the early end of leaf growth, budding and flowering. The small-borned variety 'White Lady' has a long vegetation period and a period of leaf growth, a late end of flowering and a long duration of flowering. A short flowering period is established in the small-borned variety 'Carnmoon'. Varieties that started growing later vegetated longer. The timing of the beginning and mass flowering correlated with the timing of complete leaf death. The data obtained are of interest in the practice of growing daffodils in the settlements of the Republic of Mari El.