The Effect the Method Cultivation on the Development Freesia (Freesia Eckl. ex Klatt) Ludmila Startek, Kazimierz Mynett and Piotr Zurawik Agricultural University Department Ornamental Plants Szczecin Poland Tel: 0048-91-4220851**354 Fax 0048-91-4232417 E-mail : kro@ns.rektor.ar.szczecin.pl Keywords: freesia, plastic tunnel, field, storage, corm, cut flower Abstract The experiments on 10 cultivars garden freesia (Freesia x hybrida) were conducted in the years 1997-1999. Two sizes corms were used and the corms were stored in a special climatic chamber at the temperature 28-30º C, air humidity 85%; and in a store room where the maximum temperature was 18º C, and air humidity 55-65%. Corms were always planted in May in a plastic tunnel and in open ground in the field. In both the places the beds covered with sawdust or without sawdust cover. Two different levels soil moisture and the same level fertilization were maintained. There were differences between the results obtained in particular years the experiment. The greatest effect on the developmental stages and quality freesia were from the storage conditions, and the course the weather, soil temperature in particular, the growing site and the size corms. Soil moisture and soil cover had the least effects. There were also considerable differences between the cultivars, especially between Rapid group and the others. INTRODUCTION Freesia x hybrida is photoperiodically indifferent plant, with low thermal requirements and short production cycle but very sensitive to too little light and too high soil temperature (Berghoef et al. 1986a; Berghoef and Zevenbergen 1990; Dorduin and Winden 1986; De Hertogh and Le Nard 1993). After the harvest the corms stay dormant for a certain period time. In order to accelerate the growth and flowering the plants the corm dormancy can be either shortened by storing them at appropriate temperatures or interrupted using some chemical compounds such as ethylene and growth regulators (Berghoef et al. 1986b; Imamura et al. 1996; Imanishi et al. 1997; Fukai and Goi 1998; Lee et al. 1998; Shi et al. 1997). During corm reproduction their healthiness and vigour are being reduced every year (Bach 1992). Most ten corms are obtained while growing as a cut flower but corm reproduction during freesia cultivation for cut flowers is connected with the spreading virus diseases (Kamiñska 1992). The experiments carried out in the years 1995-96 showed that there is a possibility freesia cultivation and corm reproduction in the ground under climatic condition Western Poland if a growing cycle is within 5-6 months vegetative period (Startek et al. 1997). It was also observed that the cultivation in mineral medium resulted in healthier plants and corms better quality than the cultivation in peat. In the years 1997-1999 a series experiments was conducted on freesia cultivars simultaneously under a plastic tunnel and in the field. The aim a investigations was to examine the effects : the storage temperature corms, the corms size, differentiated soil moisture and mulching; on some morphological traits the plants, and the yield coefficient and the quality corms. Proc. 8th Int. Symp. on Flowerbulbs Eds. G. Littlejohn et al. Acta Hort. 570, ISHS 2002 377
MATERIAL AND METHODS In 1997 the experiment was carried out to compare the course and the length particular developmental stages and the corm yield seven freesia cultivars: Blue Lady, Cortina, Elegance, Michelle, Polka, Pink Glow, Rapid White. The following factors were examined. 1. Pre-planting preparation corms: prepared corms (temperature 28-30ºC and humidity 85%) and stored in uncontrolled conditions (temperature ranged from 14-18ºC and humidity till 65%). 2. Size mother corms: corms over 5cm, cormlets over 3cm. 3. Growing place: field and plastic tunnel. 4. Two different levels soil moisture: 50-60% and 70-90%. In 1998 another factor was introduced: mulching - the beds covered with sawdust or without sawdust cover. In 1999 the experiment on the corms stored in uncontrolled condition (factor 1) was stopped but the effects the other factors 2-5 were still examined. During the experiments some freesia cultivars were changed. In the second year White Lace and Rapid Yellow replaced Elegance and Mitchelle. In the third year Elysee were introduced. All the cultivars studied in particular years and the factors under study are presented in Tables 1-3. In each year the experiment started in mid - May in a randomised block design, in four replications and was completed at the end October. Osmocote Plus 5-6 months was applied as a fertilizer. The same agricultural practices were used in all the combinations. There was no soil cooling. Corms from both the growing places were dug up with their foliage and placed in a special room with good air circulation. They stayed there at the temperature 18-21 C for six weeks till the stems turned yellow and dry tunics on corms were formed. After the corms had been cleaned they were graded, their weight and size were measured. Then they were dried for 4 weeks and measured again. The corms from each combination were divided into two parts: one was subjected to preparation at the temperature 28-30 C and the other one was placed in a storage room with uncontrolled temperature (till 18ºC). In May next year another experiment began. The results concerning the dynamics freesia (in percentages sprouted corms) evaluated 15 and 30 days after planting are shown in Table 1. Since there were very small differences in the results depending on the corm size, soil moisture and mulching, and the years: the means for cultivars were calculated taking into consideration only the growing place. The differences between the cultivars concerning the course vegetative and generative stages were also discussed. Height the plant during vegetation and the coefficients corms weight increase - depending on the growing place, soil moisture and soil mulching were verified statistically by variance analysis. Tukey test at 5% level confidence was used to assess the significance the differences between the means (Table 2-3). Homogenous groups were grouped and labelled with the same letters. RESULT AND DISCUSSION During a three-year experiment the prepared corms the freesias under study emerged rather evenly, 82-100% in 1-5 weeks. There were some differences in the pace depending on the cultivar and growing place (Table 1). Generally the earlier was found in the plastic tunnel when the freesias were grown from larger corms. In the first week the freesias from the beds without any cover emerged earlier but the differences disappeared within 2-3 weeks. No relationship between the soil moisture and the time was observed., Blue Lady and Michelle were found to have the shortest and most even period whereas. Cortina Elegance, Rapid White and Rapid Yellow the longest within 5-36 days. Unprepared corms sprouted unevenly and for a long time up to 10 weeks, irrespective the size and growing place. The sprouting percentage the corms were very low, only 8-46%. The corms some cultivars, e.g. Blue Lady, did not sprout at all (100% lack sprouting). We omitted the evaluation the yield unprepared corms when calculating the 378
results. All the freesias grown in the field were shorter, had more compact conformation and upright, strong leaves in comparison with the tunnel plants. All the cultivars from the tunnel were by 25-60% taller than those from the field. The cultivars that emerged first such as Blue Lady Michelle and White Lace were growing faster than the others, especially 4-8 weeks after planting. Also, in most cases the plants from larger corms were for 2-3 months taller than those from smaller ones. The relationship between the mother corm size and the plant height was maintained till the end the vegetation season in Cortina. The response cultivars, grown both in the tunnel and in the field, to varying moisture and mulching was diverse (Table 2). Therefore, we cannot draw definite conclusions. Similar results on the effects these factors on the plant development are reported by other authors (Jensen and Willumsen 1992; Kim et al. 1998). Rapid group cultivars, Rapid Yellow in particular, had a poor toleration field conditions: had poor growth, rusty discoloration leaves and stems and small corm yields. The distribution temperature in June, July and August 1997-1999 was unfavourable for freesia because the number days with the average temperature 20ºC and above at the ground level was 16-20, 14-18 and 13-21, respectively. Scorching weather after planting eliminated the effects the corm preparation and prolonged vegetation stage. Berghoef et al (1986a), Dorduin and Winden (1986), De Hertogh and Le Nard (1993), Fukai and Goi (1998) also found the negative effects high temperature on the beginning flowering and the quality flowers. The beginning flowering depends mainly on soil temperature (Immamura et al. 1996). High temperature causes later flowering but stimulates the number leaves and the pace their development. The cultivar and the size corms are great importance. According to Shi et al (1997), Che et al. (1998ab), Choi et al. (1998) and Lee et al (1998) smaller corms have longer dormancy and flower buds induced later. Among all the examined cultivars only Rapid White and Rapid Yellow turned out to be more resistant to high temperatures and had complete stages vegetative and generative development. Flower buds appeared first on them 77-87 days after planting. They flowered in the greenhouse till the beginning August - middle September and in the field till the middle August - beginning October. When the corms were harvested the plants were at the stage turning yellow and drying out. Pink Glow and Blue Lady cultivars started forming flower buds at the end August; and Michelle at the beginning -middle September, White Lace and Cortina at the beginning October and in the remaining cultivars generative stage did not begin till harvest. During harvest it was found that all the cultivars, irrespective their developmental stages produced usually a large corm 7-12 cm in circumference and a few cormlets. The number and size cormlets varied and depended on the cultivar and the growing place and to a certain degree on the size mother corms, mulching and soil moisture. Although the bulb yield differed depending on the soil moisture, the differences for the majority cultivars especially in the first and second year the experiment were not statistically significant (Table 3). The size corms had a minor affect on the total yield corms whereas the coefficients yield increase fspring corms were always higher when they were reproduced from corms +3 (cormlets) than from corms +5. In the first year for all the cultivars except Rapid White and Elegance the coefficients yield increase corms grown in the field were significantly higher than those from the tunnel. The greatest differences for years and between coefficients yield increase in the field and in the tunnel were found in Polka and Blue Lady. Particular cultivars did not respond to the growing place in the same way. In the second and third year the experiment the results were more diverse than in the first one (Table 3), whereas in all the years it was confirmed that the cultivars grown in the field produced fewer but larger corms than those grown in the tunnel. The cultivars emerging early and growing more dynamically had larger corms and higher reproduction coefficients. Corms from the field and lower level soil moisture had better developed tunic than the freesias from the tunnel and higher level soil moisture. Literature Cited Bach, A. 1992. Induction somatic embryogenesis and regeneration plants in Freesia x hybrida cultures. Folia Hortic. 1:11-22. Pl Berghoef, J., Melcherts, J., Mourits, J.W.F. and Zevenbergen, A.P. 1986a. Effect 379
temperature on initiation and development Freesia flowers. Acta Hortic. 177:636. Berghoef, J, Zevenbergen, AP. and Imanishi, H. 1986b. The effect temperature and ethylene on dormancy Freesia corms. Acta Hortic. 177, II:631-635. Berghoef, J. and Zevenbergen, A.P. 1990. The effect air and soil temperature on assimilate partitioning and flower bud initiation freesia. Acta Hortic. 266:169-176. Che, S.Q., Qin, W.Y.and Lin, Y.X. 1998a. A study on technology Freesia flower production in 6 consecutive months, Acta-Hortic.-Sinica, 25:4, 379-384. Che, S.Q. and Qin, W.Y. 1998b. Effects light quality on test-tube corm meristem in Freesia refracta, J. Shanghai Agric. College, 16:2, 121-123. Choi,-S.T., Chang, Y.D., Park, I.H. and Ahn,-H.G. 1996. Effect planting depth and existence tunic on growth and flowering in freesia forcing. J. Korean Soc. Hortic. Sci..37:4, 577-581. De Hertogh, A.A. and Le Nard, M. 1993. The Physiology Flower Bulbs. A comprehensive treatise on the physiology and utilization ornamental flowering bulbous and tuberous plants. Freesia. 21:285-296. Elsevier. London. Dourduin, J.C. and Winden, C.M.M.-van. 1986. Effect light on the time flowering, yeald and quality corm freesias grown in glasshouses. Acta Hortic. 177, I:331-340. Fukai S. and Goi M. 1998. Floral initiation and development in freesia, Technical Bulletin the Faculty Agriculture, Kagawa University, 50:2, 69-72. Imanishi, H., Lilien-Kipnis, H. (ed.), Borochov, A. (ed.) and Halevy, A.H. 1997. Ethylene as a promoter for flower induction and dormancy breaking in some flower bulbs. Acta-Hortic. 430:79-88. Imamura, Y., Doi, M. and Imanishi, H. 1996. Differences in dormancy release and flowering response to chilling in freesia corms and cormlets. J. Japa.-Soc. Hortic. Sci. 65, 1:121-127. Jensen H.E.K. and Willumsen J. 1992. Irrigation frequency and level nutrient supply for corm raised freesias. Tikedisft for Planteavl. 96, 2:1997-207. Kaminska, M. 1990. Wystepowanie silnej nekrozy lisci, deformacji i przebarwien kwiatów frezji. Rosliny Ozdobne. Prace Instytutu Sadownictwa i Kwiaciarstwa. Seria B, Tom 15:125-130. Pl Kim, D.K., Kim, J.M., Kim, J.S. and Jung, B.G. 1998. Effect mulching on summer season cut-flower production freesia in sub-alpine area, RDA-J. Hortic. Sci. 1998, 40:1, 40-44. Lee, J.J., Jeong, J.S. and Kim, J.C. 1998. Effects high-temperature storage and ethylene on breaking dormancy freesia corms, J. Korean Soc. Hortic. Scie. 39: 6, 789-793. Shi-YiMin, Tao-YiWei, Qin-WenYing, Fei-XueNan, Shi, Y.M., Tao, Y.W., Qin, W.Y. and Fei, X.N. 1997. Effects chilling and plant growth regulators on freesia flowering. Acta- Hortic. Sinica. 24, 2:185-188. Startek, L., Wraga, K. and Janicka, D.1997. Wplyw nawozenia i odmiany na plon bulw potomnych w uprawie frezji w gruncie. VII Ogólnopolski Zjazd Hodowców Roslin Ogrodniczych Hodowla, Nasiennictwo i Szkólkarstwo Roslin Ogrodniczych o Podwyzszonej Jakosci : 95-98. Szczecin, Pl. Tables 380
Table 1. Influence cultivar and place growing on dynamics freesia Cultivar Plastic tunnel Field Emergence (%) Number days Emergence (%) Number days 15 days 30 days Beginning End 15 days 30 days Beginning End Blue Lady 88.4 98.3 3 18 42,3 86,9 8 31 Cortina 78,2 92,4 5 21 27,2 87,4 9 32 Elegance 50,6 89,4 6 28 20,3 86,2 11 34 Michelle 90,4 98,1 3 17 69,4 96,3 6 20 Polka 87,2 98,6 5 19 28,2 92,4 10 32 Pink Glow 69,4 93,2 5 20 26,3 97,6 7 26 White Lace 88,2 97,3 4 17 18,4 93,1 9 32 Elysee 78,6 98,2 5 18 34,5 89,6 11 31 Rapid White 64,2 95,4 6 21 10,9 87,7 13 34 Rapid Yellow 63,4 93,1 6 23 18,1 83,4 10 36 381
Table 2. Influence year, place and method growing on height freesia cultivars five months after planting corms Cultivar Blue Lady Cortina Year Size Plastic tunnel Field corms *I **II *I **II *I **II *I **II 1997 +3 - - 79,2a 81,5a - - 56.4c 64.5b 1998 +5+ 67,4a 68,8a 70,4a 74,2a 40,6b 36,9b 41,2b 36,6b 1999 +3 78,7a 83,0a 77.7a 81,3a 44,2b 45,1b 44,1b 44,9b 1997 +3 - - 93,4a 91,2a - - 55,8c 67,3b Sawdust Without sawdust Sawdust Without sawdust +5 - - 96,8a 95,4a - - 58,8c 68,6b 1998 +5 76,9a 74,5a 79,3a 80,2a 52,3b 47,2b 47,8b 46,4b 1999 +5 85,9a 87,3a 85,6a 87,5a 54,1b 55,2b 52,3b 53,8b Elegance 1997 +3 - - 94,6a 102,5a - - 49,0b 51,3b Michelle 1997 Polka 1997 1998 1999 +5-102,7a 105,3a - - 56,8b 59,2b +3 - - 79,4a 80,5a - - 46,2b 48,8b +5 - - 81,2a 82,3a - - 52,9b 54,1b +3 - - 90,2a 85,6a - - 50,2c 59,6b +5 - - 93,3a 92,8a - - 52,8b 56,9b +3 72,4a 71,3a 76,2a 73,7a 36,4b 37,2b 38,3b 32,3b +5 76,9ab 70,1b 80,4a 75,8ab 37,2c 37,4c 39,3c 38,6c +3 85,9ab 89,5a 86,1ab 80,3b 41,0c 43,1c 42,4c 41,9c +5 80,5a 81,6a 81,7a 86,4a 41,9c 43,2c 45,3bc 46,5b Pink 1997 +5 79,8a 85,7a - - 49,4b 52,7b Glow 1998 +5 67.7a 65,4a 71,2a 68,2a 39,1bc 32,8c 43,2b 40,6b White 1998 +5 70,3a 70,0a 68,5a 70,3a 29,8bc 37,2b 25,8c 28,1bc Lace 1999 +3 83,0 84,6 81,8 83,2 38,4 38,2 37,6 40,2 Elysee 1999 +3 81,4ab 88,5a 79,3b 82,6ab 50,2c 51,0c 48,6c 49,1c Rapid 1997 +5 55,2a 53,1a - - 38,6b 39,4b White 1998 +5 57,6a 58,0a 52,6a 53,1a 34,4c 38,9bc 36,4bc 42,2b 1999 +5 61,4a 67,5a 63,0a 65,2a 32,6c 34,8c 40,0b 41,7b Rapid 1998 +3 56,8a 53,3a 56,3a 59a,9 42,3b 41,0b 39,8b 40,4b Yellow 1999 +5 52,4a 57,1a 47,7a 51,6a 34,4b 38,2b 36,6b 36,9b Key: *Soil moisture 50-60% **Soil moisture 70-90% 382
Table 3. Influence year, place and method growing on coefficient fspring corm weight increase Cultivar Blue Lady Cortina Year Size Plastic tunnel Field corms Sawdust Without sawdust Sawdust Without sawdust *I **II *I **II *I **II *I **II 1997 +3 - - 4,9b 4,2c - - 5,1a 5.3a 1998 +5 2,6d 2,7cd 2,8cd 3,0c 2,2e 3,4b 1,8f 3,8a 1999 +3 17,5a 17,6a 11,5c 13,6b 10,7d 12,0c 9,9e 10,6d 1997 +3 - - 3.9c 3,6c - - 4,7b 5,6a +5 - - 2,5b 2,6ab - - 2,9a 2,8ab 1998 +5 2,8b 1,7c 2,4b 2,6b 2,3b 3,4a 2,0bc 3,4a 1999 +5 1,8b 2,6a 2,1ab 2,4a 1,8b 2,2ab 0,9c 1,3c Elegance 1997 +3 - - 2.9b 3,1ab - - 3,0ab 3,4a Michelle 1997 Polka 1997 1998 1999 +5 - - 2,4a 2.0ab - - 1,7b 1,6b +3 - - 3,9c 3,7c - - 4,5b 5,1a +5 - - 2,0b 2,3b - - 2,2b 3,8a +3 - - 3,7c 3,9c - - 4,6b 5,0a +5 - - 1,4b 1,2b - - 1,8a 1,9a +3 3,4e 3,8e 3,6e 4,4e 6,8c 13,2a 5,2d 8,9b +5 1,8ab 1,6b- 2,1a 1,8ab 2,0ab 2,2a 2,0ab 2,1a +3 13,3c 13,3c- 12,4d 10,6e 15,8b 17,2a 9,4f 11,8d +5 3,0ab 3,4a 2,7b 2,9ab 2,6bc 3,5a 2,2c 2,8b Pink 1997 +5 - - 1.9b 1.3c - - 2,1b 2,9a Glow 1998 +5 2,3b 2,1b 2,9ab 2,9ab 2,6 3,2a 3,2a 3,5a White 1998 +5 2,0b 1,8bc 1,7bc 1,5c 2,2b 2,8a 1,8bc 1,5 Lace 1999 +3 12,9b 13,5a 9,4d 11,8c 9,8d 13,9a 7,8e 11,5c Elysee 1999 +3 9,4b 10,2a 4,8 6,9d 5,1e 8,9c 3,7f 6,9d Rapid 1997 +5 1.2a 1,6a 1,2a 1,4a White 1998 +5 2,0ab 2,3a 1,8b 1,9b 2,0ab 2,6a 1,8b 2,4a 1999 +5 2,0ab 2,2a 1,4b 2,6a 1,6ab 1,9ab 1,2b 1,4ab Rapid 1998 +5 1,8a 1,8a 1,4ab 1,6ab 1,4ab 1,9a 1,2b 1,3b Yellow 1999 +5 1,9a 1,3b 1,0bc 1,1bc 0,6c 1,0bc 0,9bc 0,9bc Key: *Soil moisture 50-60% **Soil moisture 70-90% 383