GUIDE VALUES FOR ANTHURIUM (ANTHURIUM CULTORUM BIRDSEY) GROWN IN EXPANDED CLAY Tomasz Kleiber a ; Andrzej Komosa a a

Transcription

1 This article was downloaded by: [Kleiber, Tomasz] On: 28 June 2010 Access details: Access Details: [subscription number ] Publisher Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: Registered office: Mortimer House, Mortimer Street, London W1T 3JH, UK Journal of Plant Nutrition Publication details, including instructions for authors and subscription information: GUIDE VALUES FOR ANTHURIUM (ANTHURIUM CULTORUM BIRDSEY) GROWN IN EXPANDED CLAY Tomasz Kleiber a ; Andrzej Komosa a a Department of Horticultural Plant Nutrition, Poznan University of Life Sciences, Poznań, Poland Online publication date: 25 June 2010 To cite this Article Kleiber, Tomasz and Komosa, Andrzej(2010) 'GUIDE VALUES FOR ANTHURIUM (ANTHURIUM CULTORUM BIRDSEY) GROWN IN EXPANDED CLAY', Journal of Plant Nutrition, 33: 10, To link to this Article: DOI: / URL: PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

2 Journal of Plant Nutrition, 33: , 2010 Copyright C Taylor & Francis Group, LLC ISSN: print / online DOI: / GUIDE VALUES FOR ANTHURIUM (ANTHURIUM CULTORUM BIRDSEY) GROWN IN EXPANDED CLAY Tomasz Kleiber and Andrzej Komosa Department of Horticultural Plant Nutrition, Poznan University of Life Sciences, Poznań, Poland Coefficients of variation and guide values of nutrients were determined for Anthurium cultorum Birdsey cvs. Baron, Choco, Pistache, President, Midori, and Tropical grown in expanded clay (inert medium) using drip fertigation. Fully developed leaves after freshly-cut flowers were collected as index parts for chemical analyses at two-month intervals over the period of three years ( ). Investigations were conducted at two specialized commercial farms, recording optimal yielding in terms of quantity and quality. A standard nutrient solution for anthurium hydroponics was used in fertigation. Mean guide values for six analyzed cultivars of Anthurium cultorum Birdsey are (in d.m. leaves): % nitrogen (N), % phosphorus (P), % potassium (K), % calcium (Ca), % magnesium (Mg), % sulfur (S), ppm iron (Fe), ppm manganese (Mn), ppm zinc (Zn), ppm copper (Cu), and ppm boron (B). Guide values for cvs. Baron, Choco, Pistache, President, Midori and Tropical are given in the text of this paper. A diversification was shown in guide values for analyzed cultivars in relation to certain macro- and microelements. Coefficients of variation were determined for nutrient contents in index parts of plants. A very high variation (%) was found for Mn 47.5 and Zn 41.8, high for Mg 38.5, P 32.6, S 30.6, medium for Fe 29.2, Ca 28.0, Cu 23.3 and B 20.3, while low for K 11.4 and N 9.9. Keywords: culture epiphytes, fertigation, leaves, macroelements, microelements, soilless INTRODUCTION Poland is one of the leading producers of anthurium (Anthurium cultorum Birdsey) in Europe. In terms of the volume of production it ranks second after Holland. In recent years an increase was observed in the area of cultivation of these plants using inert media and drip fertigation, as well Received 30 October 2008; accepted 13 September Address correspondence to Tomasz Kleiber, Department of Horticultural Plant Nutrition, Poznan University of Life Sciences, Zgorzelecka 4, Poznań , Poland. tkleiber@up.poznan.pl 1506

3 Guide Values for Anthurium 1507 as greenhouse climate control systems, which has resulted in a considerable increase in yields. Inert media most commonly used in Poland in anthurium growing include expanded clay and polyphenolic foam (Komosa and Kleiber, 2003b). Expanded clay is burnt clay formed into pellets with a diameter of up to 16 mm. In anthurium growing expanded clay with a diameter of 8 16 mm is used. It is a cheap type of medium, with stable physical properties and air properties dominating over water properties water capacity 12% (v/v), solid phase 16%, and air capacity 72%. At the same time it does not exhibit exchange sorption properties. Good air properties are especially advantageous in case of permanent growing of epiphytes, such as anthurium. In modern horticultural production it is necessary to regularly analyze the chemical composition of water used in fertigation. On the basis of such analyses optimal nutrient solutions are prepared to be drip applied. In order to determine the nutritional status of plants it is required to analyze contents of nutrients in leaves. This makes it possible to determine the effectiveness of nutrient uptake by plants, and thus increase the probability to obtaining qualitatively and qualitatively optimal yields. Guide values for horticultural plants were given by De Kreij et al. (1990). They are narrow ranges of nutrient contents in index parts of plants, falling within the lower and upper critical values, at which the obtained yield is optimal in terms of its quantity and quality. Moreover, guide values define optimum quantitative relations between nutrients in leaves and thus they may be used in the optimization of nutrient solution composition. The aim of the study was to determine the coefficients of variation and guide values for macro- and microelements in index parts of Anthurium cultorum Birdsey cvs. Baron, Choco, Midori, Pistache, President and Tropical, grown in expanded clay. This study was aimed not only at the determination of general guide values for the Anthurium cultorum Birdsey species, but it is primarily an attempt to define the variation of guide values depending on the cultivar. This is especially justified by the fact that at present large numbers of new cultivars are introduced to horticultural production, for which nutritional requirements have frequently not been developed. Some of these new cultivars have specific nutritional requirements in relation to certain nutrients, defined as critical or specific nutrients for a given cultivar. MATERIALS AND METHODS Greenhouses Vegetation experiments were carried out at two commercial farms specializing in anthurium growing (no. I and II) in the area of the city of Poznań (the Wielkopolska region, western Poland). Venlo type greenhouses were

4 1508 T. Kleiber and A. Komosa equipped with fertigation, climate control and recording systems as well as humidity control, shading and energy-saving curtain systems. One m bed covered 55.2 m 2, with a total of 14 plants per 1 m 2, i.e., 772 plants per bed. Agritechnical measures were performed following recommendations for anthurium. Plant Material Experimental material consisted of cultivars of anthurium (Anthurium cultorum Birdsey): Baron, Choco, Midori, Pistache, President and Tropical. Cuttings were purchased from Anthura B.V. (Bleiswijk, The Netherlands) that were grown in rock wool pots (75 cm 3 ). They were planted in greenhouse beds filled with expanded clay (ø 8 18 mm) on 8 11 August Investigations were initiated on 15 January 2002 (on two-year old plants) and completed on 30 November 2004 (five-year old plants). Anthurium was grown in expanded clay using drip fertigation in a closed system with no recirculation. The nutrient solution was distributed via dripping lines, on which emitters were spaced every 20 cm. The frequency and irrigation time depended on the season of the year. In the summer fertigation was applied six eight times, supplying 4 5 dm 3 nutrient solution per 1 m 2, while in winter it was applied two three times, using 2 3 dm 3. Approx. 20% nutrient solution dripped away from the root medium. In order to provide appropriate humidity and medium moisture content, the bed was sprayed with rainwater using microsprinklers. Fertigation Water and Nutrient Solutions On farm I tap water was used, containing nitrogen (N)- nitrate (NO 3 ) 0.07, phosphorus (P) 0.03, potassium (K) 0.06, calcium (Ca) 1.44, magnesium (Mg) 0.84, sulfur (S)- sulfate (SO 4 ) 0.25 (mmol L 1 ), iron (Fe) 0.27, manganese (Mn) 0.46, zinc (Zn) 5.47, boron (B) 0.74, copper (Cu) traces (tr.) (µmol L 1 ), ph 6.69, electrical conductivity (EC) 0.59 ms cm 1 (mmhos cm 1 ). On farm II there were two independent sources of water: a farm well and rainwater. The chemical composition of well water was as follows: N-NO , P 0.04, K 0.04, Ca 3.51, Mg 0.33, S-SO (mmol L 1 ), Fe 12.16, Mn 5.93, Zn 0.52, B 1.85, Cu 0.03 (µmol L 1 ), ph 7.46, EC 0.93 ms cm 1. Rainwater was characterized by low nutrient contents, i.e., N-NO 3 tr., P tr., K tr., Ca 0.12, Mg tr., S-SO 4 tr. (mmol L 1 ), Fe 1.11, Mn 0.44, Zn 14.27, B 0.28, Cu 0.05 (µmol L 1 ), ph 6.46, and EC 0.06 ms cm 1. Taking into consideration the chemical analysis results a standard nutrient solution for anthurium culture in expanded clay was applied (Komosa, 2000), containing N-ammonium (NH 4 )<1.0, N-NO 3 7.5, P 1.0, K 4.5, Ca 1.5, Mg 1.0, S-SO (mmol L 1 ), Fe 15, Mn 3.0, Zn 3.0, Cu 0.5, B 20.0, molybdenum (Mo) 0.5 (µmol L 1 ), ph , and EC ms cm 1.

5 Guide Values for Anthurium 1509 Sampling Samples of plant material were collected every two months, between day 14 and 16 of a given month, in January, March, May, July, September, and November, in the period of 15 January, November, Index parts of anthurium were fully-developed leaves, from plants after a fresh-cut flower (De Kreij et al., 1990). They were collected at random from the entire area of beds from plants typical for a given cultivar, healthy, well-yielding and with no signs of damage. A total of 10 leaves comprised 1 mean sample for a given cultivar. (n = 72;6termsx3yearsx2farmsx2replications). Chemical Analyses Leaves were dried at C and then ground. In order to assay total forms of phosphorus, potassium, calcium and magnesium plant material was mineralized in concentrated sulfuric acid, while for analyses of total nitrogen in a mixture of sulfuric and sulfosalicylic acids. Mineralization for assays of sulfur, iron, manganese, zinc and copper was run using the wet method in a mixture of nitric and perchloric acids (3:1, v/v), while that for boron assays using the dry method in the presence of calcium hydroxide in a muffle furnace (Elektro Therm type LM 312,24, Linn High Therm GmbH, Eschenfielden, Germany); (IUNG, 1972). After mineralization of plant material the following determinations were performed: N, total nitrogen using the distillation method according to Kjeldahl in a Parnas Wagner apparatus; P, colorimetrically with ammonia molybdate; K, Ca, Mg, Fe, Mn, Zn, and Cu using atomic absorption spectroscopy (AAS) (AAS3; Carl Zeiss Jena; Thornwood, NY, USA); S using nephelometry with barium chloride (BaCl 2 ); and B colorimetrically with curcumin. Statistical Analyses They were used to determine ranges of guide values for nutrients in index parts of plants, taking into consideration coefficients of variation (Kenworthy, 1961). The following approach was used in the determination of guide values: a) It is the range of nutrient content including +/ 10% deviation from the mean content of a nutrient in index parts of plants, i.e., a 20% band placed on the mean content of a given nutrient in index parts of plants, b) In the 20% range of nutrient content the coefficient of variation of a given nutrient in index parts, which was, e.g., 9.9% for nitrogen or 47.5% for manganese (Table 1),

6 TABLE 1 Coefficients of variation coefficients and nitrogen, phosphorus, potassium, calcium, magnesium and sulfur guide values in different anthurium cultivars (means from 3 years; n = 72) Nutrient Nutrient contents in the Coefficients Guide values (% in d.m.) contents in the Coefficients Guide values (% in d.m.) index plant part of variation index plant part of variation Cultivar (% in d.m.) CV (%) Calculated Rounded (% in d.m.) CV (%) Calculated Rounded N Ca Baron 1.50 d a Choco 1.68 a b Midori 1.42 e c Pistache 1.58 b c President 1.57 c a Tropical 1.55 c b Mean P Mg Baron 0.38 a d Choco 0.40 a b Midori 0.33 c c Pistache 0.36 b a President 0.39 a a Tropical 0.39 a b Mean K S Baron 3.64 c b Choco 4.14 a a Midori 3.98 b a Pistache 4.07 b c President 4.04 b e Tropical 4.22 a d Mean

7 Guide Values for Anthurium 1511 c) Guide values were calculated according to the following formulas: A = S (0.1 S S 0.01 W ); B = S + (0.1 S S 0.01 W ) where: A lower range of guide values; B upper range of guide values; S mean nutrient content in index parts of plants; W coefficient of variation in nutrient content in index parts of plants expressed in%; 0.1 the calculation of 10% deviation from the mean nutrient content in index parts of plants (10%:100%); 0.01 conversion of the coefficient of variation W (expressed in%) into absolute values. Example: The mean nitrogen content in index parts of cv. Tropical is S = 1.55% N (Table 1). The coefficient of variation for nitrogen content in index parts of cv. Tropical is W = 9.5% (Table 1). A = 1.55 ( ) = 1.38%N 1.40%N, B = ( ) = 1.72%N 1.70%N, The range of guide values is % N. d) Guide values for macroelements were calculated to two decimal places, rounding the last place to zero (e.g., 1.60). For microelements iron, manganese, zinc and boron they were calculated to the first decimal place, rounding the last place to zero (e.g., 35.0), while for copper to two decimal places, rounding the last place to zero or five (e.g., 5.60 or 5.65). RESULTS AND DISCUSSION Nitrogen Nitrogen content in plants was characterized by high stability the coefficient of variation (CV) was 9.9%. For analyzed cultivars it ranged from 7.4% ( President ) to 9.5% ( Tropical ). Mean nitrogen content from three years of the study and for 6 cultivars in index parts of anthurium was 1.55% N (Table 1). Guide values for nitrogen fell within the range of % N (Table 2). Lower contents were recorded for cv. Midori ( % N) and Baron ( % N), while higher for Choco % N. Similar data were given by Komosa and Kleiber (2002a, 2003aa). Chen et al. (2003) stated that mean contents of nitrogen fell within the range of % N. Guide values determined in this study were lower than those reported by Anthura (1998). They also differ from contents recommended by De Kreij et al. (1990) and Higaki et al. (1992). Sonneveld and Voogt (1993) showed higher contents for culture on polyphenolic foam. Established contents fell

8 TABLE 2 Coefficients of variation coefficients and iron, manganese, zinc, copper and boron guide values in different anthurium cultivars (means from 3 years; n = 72) Nutrient Nutrient contents in the Coefficients Guide values (% in d.m.) contents in the Coefficients Guide values (% in d.m.) index plant part of variation index plant part of variation Cultivar (% in d.m.) CV (%) Calculated Rounded (% in d.m.) CV (%) Calculated Rounded Fe Cu Baron 59.8 a b Choco 46.0 c a Midori 46.6 c c Pistache 54.0 b c President 56.3 a b Tropical 56.7 a b Mean Mn B Baron 40.0 b b Choco 56.9 a b Midori 45.9 a a Pistache 32.1 b a President 32.0 b b Tropical 39.5 b b Mean Zn Baron 59.5 c Choco 63.7 b Midori 70.1 a Pistache 53.6 d President 65.6 a Tropical 65.6 a Mean

9 Guide Values for Anthurium 1513 within the range given by Mills and Scoggins (1998), i.e., % N, in mature leaves of scoria-grown anthurium. Phosphorus Mean phosphorus content from all analyzed anthurium cultivars was 0.38% P in index parts (Table 1). The lowest amounts of phosphorus (0.33% P) were detected in cv. Midori, while the biggest amounts (0.40% P) in cv. Choco (Table 1). Guide values for all cultivars were % P. The most stable content of this nutrient was recorded in cv. Baron (CV 27.0%), while the biggest fluctuations were found for cv. Midori (CV 40.9%). The established range of guide values was consistent with that given by Mills and Scoggins (1998). Chen et al. (2003) defined the range of % P as appropriate for commercial anthurium growing. Lower contents were reported by De Kreij et al. (1990), as well as Higaki et al. (1992) for traditional anthurium growing and Sonneveld and Voogt (1993) for culture on polyphenolic foam. Potassium Mean potassium content was 4.01% K (Table 1). The coefficient of variation (CV) for potassium was 11.4% and ranged from 8.0% for Midori to 13.7% for cv. President (Table 1). The lowest amounts of potassium were detected in cv. Baron (3.64%), while the highest in Tropical (4.22% K). Guide values for this nutrient, for the mean of cultivars, were % K (Table 1), with higher contents recorded in cv. Tropical and Choco, % and % K, respectively. The range of % K was optimal for cv. Baron. The established range of guide values fell within the range reported by De Kreij et al. (1990) and Anthura (1998). Chen et al. (2003) presented a wider range of % K. Higaki et al. (1992) found 2.07% K, while Sonneveld and Voogt (1993) 3.52% K in index parts. The % range for K was determined in young anthurium leaves by Mills and Scoggins (1998). Calcium Mean content in index parts was 1.59% Ca. Distinct differences between cultivars were found. The lowest content of calcium was recorded in cv. Midori (1.40%), while the highest (1.75%) for cv. President (Table 1). The recorded coefficient of variation for calcium in leaves of anthurium was CV = 28.0%. Mean guide values for analyzed cultivars were % Ca. Midori was the cultivar with lower index contents ( % Ca), while higher were found for cv. President ( % Ca). Cultivars giving lower yields, such as Baron and President, had higher contents of calcium than

10 1514 T. Kleiber and A. Komosa cultivars giving higher yields, i.e., Tropical and Midori. Chen et al. (2003) reported that in index parts of anthurium plants grown in commercial farms calcium content was most frequently %. De Kreij et al. (1990) for traditional growing recommended % Ca. Higaki et al. (1992) and Sonneveld and Voogt (1993) gave lower contents. Magnesium The mean for analyzed cultivars magnesium content was 0.26% Mg (Table 1). The lowest amount of this nutrient was found for cv. Baron (0.21%), while the highest in cv. President (0.32%). Guide values were % Mg (Table 1). Higher contents of this element need to be recommended for cv. President ( % Mg). The coefficient of variation (CV) determined for magnesium for all cultivars was 38.5%. The content of 0.28% Mg defined by Higaki et al. (1992) fell within the range of values recommended for anthurium. Also ranges given by Komosa and Kleiber (2003b) were similar to those reported in this study. Chen et al. (2003) proposed the mean contents of magnesium of % Mg. Contents of magnesium in anthurium leaves determined by De Kreij et al. (1990) for traditional culture, as well as Sonneveld and Voogt (1993) for polyphenolic foam culture and Mills and Scoggins (1998) for scoria growing are markedly higher than those reported in this study. Sulfur The mean content of this nutrient in index parts of anthurium plants was 0.33% S. Guide values fell with the range of % S (Table 1). Lower sulfur contents may be recommended for cv. Tropical, President and Pistache. In turn, Sonneveld and Voogt (1993) recommended markedly lower sulfur contents in index parts (0.22% S). Chen et al. (2003) reported the most frequent contents of sulfur in commercial cultures were % S in index parts. Variation in sulfur content was found to vary in analyzed cultivars. The lowest coefficient of variation was established for Choco (CV = 19.6%), while the highest for Tropical (33.9%). Iron Mean iron content in index parts of anthurium plants was 53.2 ppm Fe (Table 2), while the coefficient of variation (CV) was 29.2%. Baron was the cultivar with the highest content of this element (59.8 ppm), whereas the lowest amount of iron was recorded in cv. Choco (46.0 ppm Fe). Guide values for iron in case of anthurium are ppm Fe in d.m. index parts. For cv. Choco guide values were lower, amounting to ppm Fe. Lower contents should also be recommended for Midori ( ppm Fe). Only for cv. Baron guide values were higher, falling within the

11 Guide Values for Anthurium 1515 range of ppm Fe. A much wider range ( ppm Fe) in commercial cultures was reported by Chen et al. (2003). The range of guide values was consistent with data given by De Kreij et al. (1990) for traditional growing and by Mills and Scoggins (1998) for scoria culture. Manganese The mean content in analyzed cultivars was 41.1 ppm Mn (Table 2). The lowest content of this element was found for cv. President (32.0 ppm Mn), while the highest for cv. Choco (56.9 ppm Mn). The range of ppm Mn should be assumed as guide values for manganese. Lower contents of this nutrient are recommended for cv. President and Pistache ( and ppm Mn, respectively), while definitively much higher for cv. Choco ( ppm). Manganese is characterized by high coefficients of variation determined in studies on the analyzed cultivars, ranging from 30.5% ( Baron ) to 55.1% ( Midori ). Mills and Scoggins (1998) reported a wider range of this nutrient, ranging from 41.0 to ppm Mn. Manganese content in commercial cultures fell within the range of ppm Mn (Chen et al ). Anthura (1998) for traditional growing systems recommended the range from 38.0 to ppm Mn. Zinc The mean content of the element in index parts of anthurium plants was 63.0 ppm Zn (Table 2). Proposed guide values for zinc fall within the range of ppm Zn in d.m. index parts. Pistache was the cultivar with the lowest zinc content, as proposed guide values are ppm Zn. Higher guide values are given for cv. Midori ( ppm Zn; Relatively high fluctuations in zinc content were recorded in index parts of anthurium plants. The coefficient of variation for zinc content in analyzed cultivars was 41.8%. Determined guide values fall within the range recommended by De Kreij et al. (1990) and Mills and Scoggins (1998). Similar zinc contents were also given by Kleiber and Komosa (2004). Chen et al. (2003) stated that the range of mean contents of this element range from 20.0 to ppm Zn in index parts. Higaki et al. (1992) in traditional growing found the mean content of 40.4 ppm Zn. Copper The mean copper content was 5.82 ppm Cu. The lowest content was established in Pistache (5.55 ppm Cu), while the highest of 6.39 ppm Cu in cv. Choco (Table 2). Guide values for copper in analyzed anthurium cultivars fall within the range of ppm Cu. Only the above mentioned cv. Choco is characterized by markedly higher guide contents ( ppm Cu). The determined coefficient of variation for this nutrient in

12 1516 T. Kleiber and A. Komosa analyzed cultivars was 23.3%. Ranges similar to those established in this study were given by Komosa and Kleiber (2002b). All available literature sources reported markedly higher contents. Usually in anthurium index parts, coming from commercial cultures, this range was ppm copper (Chen et al. 2003). Boron The mean content of this element in anthurium index parts was 73.6 ppm B (Table 2), while the determined coefficient of variation (CV) was 20.3%. Guide values for analyzed cultivars are ppm B. In case of cv. Midori and Pistache they are higher, and ppm B, respectively. Similar boron content was reported by Komosa and Kleiber (2002b). Mean contents of this element in commercial cultures were ppm (Chen et al. 2003). De Kreij et al. (1990) and Anthura (1998) in traditional growing of anthurium gave contents ranging from 54.0 to 76.0 ppm B. Markedly lower boron values in scoria cultures were reported by Mills and Scoggins (1998). Certain cultivars are characterized by higher contents of some nutrients. Such cultivars include Tropical and Choco, exhibiting the highest ranges of guide values for potassium amounting to % and % K, respectively. Cultivars Baron and President had the highest ranges for calcium of % and % Ca, respectively. Cultivar Baron is characterized by high iron contents of 52, ppm, Choco by high manganese contents of ppm and that of copper ppm, Midori zinc levels of ppm, while Pistache boron contents of ppm. These were contents divergent from means for Anthurium cultorum Birdsey. Nutrients, in case of which a given cultivar has special requirements, are referred to as critical nutrients (Alexander, 1986). It is highly probable that nutrient solutions applied in fertigation of these cultivars should have elevated levels of these elements. They may have an effect on quantitative and qualitative yield parameters. It seems that the method of determining guide values, proposed in this study, may prove useful in the diagnostics of nutrient requirements of horticultural plants. It is a method developed by Kenworthy (1961) for orchard plants. It was modified by the authors of this study for the diagnostics of herbaceous plants. The modification consisted in the determination of guide values within the range of +/ 10% deviation from the mean content of a nutrient for a given species or cultivar, taking into consideration the coefficient of variation for this nutrient. The adoption of this method facilitates relatively fast determination of guide values, which may also be determined as standard contents. This method may be especially useful for ornamental plants, due to the high increase in the number of new cultivars, grown commercially in greenhouses, which are introduced each year.

13 Guide Values for Anthurium 1517 CONCLUSIONS The three-year study was conducted in the years on two commercial farms using standard nutrient solution in drip fertigation in anthurium growing on the medium of expanded clay, facilitated the determination of guide values for macro- and microelements. Guide values were determined in index parts of plants, which were fully developed leaves after fresh-cut flowers. Guide values include +/ 10% deviation from the mean (a total 20% rage) in the content of a nutrient, taking into consideration the coefficient of variation for a given nutrient for a specific cultivar. Studies were conducted on 6 cultivars: Baron, Choco, Midori, Pistache, President and Tropical. Means from 6 cultivars for guide values for Anthurium cultorum Birdsey were (% in d.m): N , P , K , Ca , Mg , S , and (ppm in d.m) Fe , Mn , Zn , Cu , B Guide values were also established for cv. Baron, Choco, Midori, Pistache, President and Tropical. Varietal variation was shown in relation to some nutrients. Cultivars Tropical and Choco are characterized by high ranges of potassium content of % and % K, respectively, Baron and President have high calcium ranges of % and % Ca, respectively. Cultivar Baron exhibits high contents of iron amounting to ppm, Choco manganese ppm and copper ppm, Midori zinc ppm, while Pistache that of boron ppm. Recorded guide values made it possible to modify the assessment of the nutritional status of plants, as well as optimize the composition of nutrient solutions for a given cultivar. The necessary element in the determination of guide values was to determine the coefficients of variation for contents of macro- and microelements in index parts of plants. A very high variation (%) was found for Mn 47.5 and Zn 41.8, high for Mg 38.5, P 32.6, S 30.6, medium for Fe 29.2, Ca 28.0, Cu 23.3, B 20.3, while low for K 11.4 and N 9.9. Knowledge of the coefficients of variation is essential in the interpretation of results of analyses conducted on plants for diagnostic purposes. The method proposed by Kenworthy (1961) for the determination of optimum contents of nutrients, modified in this study, may be applied in the determination of guide (or standard) values for anthurium. It seems that it may be used also for other ornamental plants. This makes it possible to establish relatively fast the narrow ranges of nutrient contents in index parts of plants, at which optimal yielding is found in terms of both quantity and quality parameters. This also makes it possible to determine the variation in guide (standard) values depending on the cultivar. It is of great importance in present-day horticultural production, characterized by large numbers of new cultivars, introduced annually.

14 1518 T. Kleiber and A. Komosa ACKNOWLEDGMENTS The study was co-financed by the State Committee for Scientific Research, contract no. 0381/P06/2004. REFERENCES Alexander A Optimum timing of foliar nutrient sprays. In: Proceedings of the First International Symposium, Foliar Fertilization, ed. A. Alexander, pp Dordrecht: the Netherlands: Martinus Nijhoff. Anthura, Cultivation Guide Anthurium: Global Know-Hod for Growers around the World Bleiswijk, the Netherlands: Anthura B. V. Chen, J., D. B. McConnell, R. Henny and K. C. Everitt Cultural guidelines for commercial production of interiorscape anthurium. ENH 956. Gainesville, FL: Environmental Horticulture Department Florida Cooperative Extension Service, University of Florida. De Kreij, C., C. Sonneveld, M. G. Warmenhoven, and N. Straver Guide values for nutrient element contents of vegetables and flowers under glass. Report No. 15. Naaldwijk, the Netherlands: Research Station for Floriculture and Glasshouse Vegetables. Higaki, T., J. S Imamura, and R. E. Paull N, P and K rates and leaf tissue standards for optimum Anthurium andraeanum flower production. HortScience 27: IUNG Analytical methods in agricultural-chemistry stations. Part II. Plant analyses. Pulawy, Poland: IVNG. Kenworthy, L Interpreting the balance of nutrient elements in leaves of fruit trees. In: Plant Analysis and Fertilizer Problems, ed. Walter Reuther, pp Washington, DC: American Institute of Biological Sciences. Kleiber, T., and A. Komosa Dynamics of nutrient contents in leaves and changes of nutrient contents in rhizosphere in growing of anthurium. In: IX Anthurium Growers Conference, pp Skierniewice, Poland: Research Institute of Pomology and Floriculture. Komosa, A Plant and substrate analyses as the indicator of nutrient status of anthurium. In: V Anthurium Growers Conference, pp Skierniewice, Poland: Research Institute of Pomology and Floriculture. Komosa, A., and T. Kleiber. 2002a. Plant analysis in diagnostics of anthurium nutrient status grown in inert media. Anuu. Univ. Of Agric. Poznan. Ogrodn. 35: Komosa, A. and T. Kleiber. 2002b. Temporary guide values of microelements for anthurium grown in inert media. In: VII Anthurium Growers Conference, pp Skierniewice, Poland: Research Institute Of Pomology and Floriculture. Komosa, A., and T. Kleiber. 2003a. Nutrient contents in leaves of anthurium grown in inert media. Part I. Macroelements. Anuu. Univ. Of Agric. Poznan Ogrodn. 36: Komosa, A., and T. Kleiber. 2003b. Anthurium substrates and nutrition. In: VIII Anthurium Growers Conference, pp Skierniewice, Poland: Research Instiute of Pomology and Floriculture. Mills, H. A., and H. L. Scoggins Nutritional levels for anthurium: Young versus mature leaves. Journal of Plant Nutrition 21: Sonneveld, C., and W. Voogt The concentration of nutrients for growing Anthurium andreanum in substrate. Acta Horticulturae 342: