Growth and Quality of Oriental Lilies at Different Fertilization Levels

Growth and Quality of Oriental Lilies at Different Fertilization Levels J. Treder Research Institute of Pomology and Floriculture ul. Pomologiczna 18 96-100 Skierniewice Poland Keywords: lily forcing,, leaf, SPAD value, shape Abstract The aim of the experiment was to evaluate the effect of different levels on growth, ing and quality of Oriental lilies. Four lily varieties Acapulco, Le Reve, Sorbonne and Siberia were grown in boxes in summer months, from May to August. Before planting, the peat and sand (9:1) growing medium was amended with the controlled release fertilizer (CRF), (16:18:21 + 3 MgO), at three levels: 0, control; 2, and 4 g L -1 of soil. During the vegetation period half of the plants were additionally fed using weekly irrigation with complete fertilizer Peters (15:11:29) at concentration. Higher levels of, especially in the treatment without additional during vegetation, resulted in better quality of all cultivars used in the experiment. Intensively fertilized plants were taller, had longer buds, higher fresh and larger, dark green leaves. The buds had better shape and were more upward, compared with non-fertilized control. For cultivars with long vegetation periods, application of only liquid feeding, without CRF, applied before planting, was insufficient for good plant quality. INTRODUCTION Lilies are very important as cut s and pot plants, and they are usually forced year-round. During winter, the most limiting factor in obtaining good quality is insufficient light (Beattie and White, 1993; De Hertogh, 1989). However, when plants are growing during spring and summer months, other factors such as bulb quality after long storage, a high quality, well aerated growing medium and proper are very important. Lilies are considered to have low to moderate nutrient requirements (Erwin, 1998). It was shown that lilies from different groups (Asiatic, Orientals) have different nutrient requirements (Beattie and White, 1993; Sonneveld et al., 1999). When light conditions during Oriental lily forcing were optimal nutrient uptake increased with increasing level (Treder, 2001, 2003). It seems that cultivars characterized by a long vegetation period have higher nutrient requirements. Lilies are sensitive to high salinity of growing medium, especially at the beginning of cultivation. The application of CRF before planting can be a good solution to ensure extended supply of nutrients and prevent high medium salinity. The information about nutrient requirements of lilies during cut production and about CRF application for this plant is rather limited. The objectives of this study were to determine the influence of intensity and application of slow-release fertilizer on growth, ing and plant quality during forcing some Oriental lily cultivars. MATERIALS AND METHODS The experiment was performed in a greenhouse, in the rth of Poland. Precooled bulbs (13/14 cm) of 4 Oriental cultivars Acapulco, Le Reve, Siberia and Sorbonne, obtained from commercial grower, were planted in boxes (40 x 60 cm) in the end of May. The boxes were filled with 30 liters of growing medium, consisting of peat and sand (9:1 by volume). There were 15 bulbs in each box. The growing medium was adjusted to ph 5.8 with lime and amended with 1 kg m -3 of a commercially available fertilizer (13.6 N - 2.8 P - 15.9 K - 2.7 Mg plus microelements). Before bulb planting the controlled release Proc. IX th Intl. Symp. on Flower Bulbs Eds.: H. Okubo, W.B. Miller and G.A. Chastagner Acta Hort. 673, ISHS 2005 297

fertilizer 16:8:21 + 3 MgO (Haifa, Israel) at three levels were used: 0 control, 2 and 4 g L -1. During the rooting phase (the initial 4 weeks after planting), plants were kept at 10-13 C and then moved to the greenhouse. Half of all plants were irrigated with water alone and half with water and soluble fertilizers. There were 4 boxes with lilies in each treatment. started 4 weeks after planting and was initially conducted using calcium nitrate and potassium nitrate at 1 and 0.5 g L -1, respectively (N 225, K 191 mg L -1 ). When buds reached the of 1 to 3 cm, nitrogen level was decreased and being carried out weekly with complete fertilizer Peters 15:11:29 (Scotts, Poland) at concentration. Fertilization was continued up to ing. The temperature in the greenhouse was maintained between 25 C (day maximum) and 16 C (night minimum). At ing, when first buds showed colour, 25 uniform plants from each treatment were chosen and then harvested. Usually plants with 2 buds for Siberia and 3 buds for other varieties were chosen. Then ing date, plant, fresh, and of two upper leaves, and bud were recorded. coloration () was measured on the top two leaves, just above the inflorescence, using a SPAD 502 meter (Minolta, Japan). The 15 single records were done on the middle part of leaf blade to calculate the average value for each leaf. After ing, soil samples (extract 2:1) were analysed for total soluble salts (TSS) evaluation using conductivity meter (Type OK-102/1, Badelkis, Hungary). The experiment was split plot design with doses as a main plots and liquid as a subplots. The results from each plant, chosen from the treatment, were treated as a replicates. Statistical significance of the treatments was tested using analysis of variance and the means were compared using Duncan multiple range test. RESULTS AND DISCUSSION The application of both and water soluble fertilizer during lily forcing significantly improved quality of all cultivars. As expected, days varied between the cultivars. The earliest was Le Reve ing after about 75 days, then Acapulco, 79 days, Sorbonne, 84 days and Siberia, 91 days (Table 1, 2, 3, 4). However, Le Reve also had the shortest stems, the smallest leaves, buds and the lowest fresh compared with other cultivars. The late ing Siberia had similar fresh to Acapulco and the biggest leaves and the longest buds. Siberia had also the darker leaf color. Fertilization influenced ing time, except for Siberia (Table 3) but the differences, even if statistically significant, were not larger than one day. It was shown on the Oriental cultivars Olympic Star and Casa Blanca that intensive delayed ing, especially in the autumn season (Treder, 2000). With Acapulco, was not influenced by (Table 1), but with the other cultivars, the tallest plants were obtained when both and soluble fertilizers were given (Table 2, 3, 4). application and liquid significantly increased plant fresh. Intensively fertilized plants were 13, 12, 25 and 23% heavier in Acapulco, Le Reve, Siberia and Sorbonne, respectively, compared with nonfertilized control. Almost twice as higher increase in in case of Siberia and Sorbonne could be explained by longer cultivation time and greater benefits from prolonged liquid. However, the obtained data showed that for these cultivars weekly liquid feeding was indispensable for good plant quality. Intensive positively affected lily inflorescence shape. Flower buds had better shape and were more upward, compared to non-fertilized control (Fig. 2). The fertilized plants of all cultivars had bigger and better colored leaves. The SPAD values are usually positively correlated with chlorophyll content in the leaves. The leaf, expressed in SPAD value, increased with increasing levels (Table 1, 2, 3, 4). As expected, varied in their leaf color intensity, and these were reflected in their SPAD values: 58.5, 64.7, 64.9 and 70.7 for Le Reve, Acapulco, Sorbonne and Siberia, respectively. Intensive (highest dose and liquid 298

during vegetation) increased SPAD values, compared with non-fertilized control, by 23.7, 34.0, 35.4 and 39.6% for Sorbonne, Acapulco, Le Reve and Siberia, respectively. Tribulato et al. (2003) showed that leaf color intensity of Elite (Asiatic) and Star Gazer (Oriental) lilies was influenced by both growing substrate and variety. Better lily leaf coloration was also obtained on lilies Star Gazer and Laura Lee when plants were grown with high levels and supplementary lighting (Treder and Kubik, 2000; Treder, 2003). The data of the present study confirm the results of Kiplinger et al. (1977). They observed that lilies grown with Osmocote, incorporated to growing medium before planting and then irrigated with water alone were pale green and of poor quality compared to plants grown with both Osmocote and irrigated with fertilizer-containing water. As was expected, the TSS in growing media was the highest in all cultivars, when plants received the most intensive (Fig. 1). But even in these conditions TSS was not very high according to De Hertogh (1989) and Sonneveld et al. (1999), between 1.1 and 1.5 g NaCl dm -3 in Le Reve and Siberia, respectively. The use of without liquid resulted in too low level of fertilizers in growing medium to ensure good lily growth and quality. CONCLUSIO The results of present study showed that Oriental lilies require intensive during forcing to obtain good quality. Fertilization program should be adjusted to cultivar requirements and forcing time to give the nutrients no more than necessary and no less than required. Literature Cited Beattie, D.J. and White, J.W. 1993. Lilium - hybrids and species. p.423-454. In: A.A. De Hertogh and M. Le Nard (eds.), The Physiology of Flower Bulbs, Elsevier, Amsterdam. De Hertogh, A.A. 1989. Holland Bulb Forcers Guide. 4 th ed., Int. Flower Bulb Center, Hillegom, The Netherlands. 369p. Erwin, J.E. 1998. Easter lily production. Minn. Comm. Flower Grow. Bull. 47(5):1-10. Kiplinger, D.C., Tayama, H.K. and Staby, G. 1977. Slow-release fertilizers and fertilizer injection on growth of several lily cultivars. Ohio Florist Assoc. Bull. 509:9. Sonneveld, C., Baas, H.M., Nijssen, H.M.C. and de Hoog, J. 1999. Salt tolerance of crops grown in soilless culture. J. Nutrition 22(6):1033-1048. Treder, J. 2000. Influence of on growth. Flowering and mineral nutrient content of oriental lilies. Zesz. Probl. Post. Nauk Rol. 7:375-380. (in polish with English abstract). Treder, J. 2001. The effect of light and nutrition on growth and ing of oriental lilies. Acta Hort. 548:523-528. Treder, J. 2003. Effects of supplementary lighting on ing, plant quality and nutrient requirements of lily Laura Lee during winter forcing. Scientia Hort. 98:37-47. Treder, J. and Kubik, M. 2000. Growth, ing and partitioning of 14 C-assimilate in Oriental lily Star Gazer as affected by light level and removal. J. Hort. Sci. & Biotech. 75(3):277-282. Tribulato, A., to, G. and Argento, S. 2003. Soilless growing on quality production in lily. Acta Hort. 614:749-754. 299

Tables Table 1. The effect of doses before planting and liquid on growth and ing of oriental lily Acapulco. 77.9 bc 78.3 c 85.3 a 87.7 ab 87.7 a 90.1 ab 13.5 a 13.6 a 4.4 a 4.3 a 11.6 a 11.9 b 55.0 a 58.8 b 78.3 c 78.4 c 85.1 a 87.0 ab 87.6 a 95.2 bc 13.8 a 13.5 a 4.4 a 4.3 a 12.0 b 11.9 b 65.0 c 67.2 d 4 g L -1 77.7 ab 77.4 a 88.2 b 87.3 ab 98.9 c 96.6 c 14.8 c 14.3 b 4.8 b 4.6 b 12.0 b 11.9 b 68.4 d 73.7 e Explanations: Means followed by the same letters in columns do not differ significantly according to Duncan s test (P 0,05).,, and means: significant at P 0,001; 0,01; 0,05 and not significant, respectively. Table 2. The effect of doses before planting and liquid on growth and ing of oriental lily Le Reve. 75.0 a 75.4 a 72.2 ab 76.9 c 70.2 a 71.0 ab 12.6 a 13.2 ab 3.0 a 9.7 a 9.7 a 49.4 a 53.7 b 75.1 a 76.0 b 76.4 c 75.9 c 79.9 c 77.4 c 13.3 ab 12.9 ab 3.0 a 9.8 a 10.1 b 58.2 c 59.7 c 4 g L -1 Explanations: see Table 1. 74.9 a 75.1 a 70.6 a 73.6 b 76.4 bc 78.4 c 12.9 ab 13.6 b 10.1 b 10.3 b 62.8 d 66.9 e 300

Table 3. The effect of doses before planting and liquid on growth and ing of oriental lily Siberia. 91.1 a 91.1 a 67.6 a 69.7 ab 80.8 a 85.0 ab 14.9 a 15.6 b 5.6 a 5.7 ab 12.2 a 12.2 a 59.8 a 67.0 c 91.2 a 91.4 a 69.6 ab 73.9 c 83.4 a 92.7 bc 16.0 b 17.1 c 5.8 bc 5.8 bc 12.4 a 12.8 b 62.8 b 73.2 d 4 g L -1 91.4 a 91.4 a 71.9 bc 72.2 c 100.6 c 99.9 c 17.0 c 17.4 c 5.9 bc 6.0 c 13.3 c 13.4 c 77.8 e 83.5 f Table 4. The effect of doses before planting and liquid on growth and ing of oriental lily Sorbonne. 83.3 a 83.6 abc 78.4 ab 81.7 c 81.8 a 81.2 a 12.5 a 12.5 a 4.8 a 4.8 a 11.2 a 11.3 ab 56.9 a 59.3 b 84.0 c 83.9 bc 77.8 a 80.1 c 87.3 ab 88.2 ab 12.9 b 12.9 b 4.7 a 4.8 a 11.7 c 11.8 c 66.0 c 68.4 d 4 g L -1 83.3 a 83.4 ab 78.2 ab 80.3 bc 92.9 b 100.8 c 13.0 b 13.8 c 4.6 a 4.7 a 11.5 bc 11.6 c 68.2 d 70.4 e 301

Figures Fig. 1. The influence of and liquid on total soluble salts in the growing medium at ing. Fig. 2. The influence of on inflorescence shape in Siberia. Left - horizontal position of buds in non-fertilized control, right - upright buds in intensively fertilized plants. 302