Jpn. J. Trop. Agr. 51(3) : 84-94, 2007

Effect of Concentrations of Nutrient Solutions in Aeroponic and Drip Systems on the Growth of Touki, acutiloba Kitagawa

Ninh Thi PHIP, Hiroshi NOJIMA* and Toru TASHIRO

Faculty of Horticulture, Chiba University

Abstract •eTouki•f, , Angelica acutiloba Kitagawa, are usually cultivated in soil, under which its yield and root quality are unstable. Although fertilizer application exerts a substantial impact on yield, the optimal level has not been known for the

cultivation in soil. Therefore, the present study was undertaken to examine the growth of Touki plants with different

concentrations of nutrient solution in aeroponic and systems. Four nutrient concentrations, i.e.,100%, 200%, 50%,

and 25% of the standard nutrient solution (•gEnshi•hformula) were tested:. In the aeroponic system, where a mist of nutrient

solution was sprayed around suspended roots of the plants, the plants were grown from March 15 to June 6, 2005. In the drip irrigation system the plants were grown from May 2 to July 25, 2006. In the aeroponic system, the values of the growth parameters of the Touki plants at 12 weeks after transplanting were higher in the order of 100% > 50% > 200% > 25% of the standard solution. In the drip irrigation system the growth parameters were higher in the order of 100% > 200% > 50% > 25% of the standard solution. The •gEnshi•h nutrient solution of 100% was optimal for the growth of the Touki plants in both systems. The growth, especially root growth, was more vigorous in the aeroponic system than in the drip irrigation system. In the drip irrigation system, however, the root/shoot ratio and root C/N ratio were higher, and the development of secondary roots was

stimulated. As the secondary roots of Touki plants are mainly used as raw materials for medicine in Viet Nam, the drip

irrigation system is recommendable as an advanced culture system.

Key Words: Hydroponic culture, Medicinal plants, Mineral nutrition, Touki plant

Heavier seeds and seeds having a higher specific Introduction gravity produced more vigorous seedlings. Yomo et al. •e Touki•fplants, Angelica acutiloba Kitagawa, are (1998a) reported that the growth rate of Touki plants in usually cultivated in field soils. The plants often require hydroponic culture was higher than that in conven-

2 years for achieving root maturity in , but one tional soil culture, while the ligustilide content was year in Viet Nam (Pham, 2000). During the growth nearly the same in plants grown both in hydroponic period, the plants are subjected to numerous stresses, culture and soil culture. Yomo et al. (1998b) also

such as diseases and insects attacks, which directly reported that Touki plants grown in Kanuma soil affect the productivity and quality. In addition, it is very produced larger roots and exhibited higher values for difficult to determine the optimal quantity of fertilizer the fresh and dry weight than those grown in other for plants grown in soil (Lissner et al., 2003). substrates (e.g. rockwool, river , hydroball, etc.).

Harvesting of roots, i.e., extracting roots from soil, is is a form of hydroponic system, in

extremely laborious and most of the fragile secondary which a mist of nutrient solution is sprayed around

roots are lost during the harvest, leading to a roots in a chamber. Aeroponics is effective for

substantial loss of potential yield. Low productivity and initiating rooting of cuttings and for extracting low profitability inhibit the expansion of the cultivated ingredients from the roots of medicinal plants area of Touki plants. Therefore, in Viet Nam, 80% of the (Burgess et al., 1998; Pagliarulo et al., 2000; Gontier et total amount of Touki roots is imported from as al., 2002). Even though aeroponics offers several

raw materials for medicinal purposes (National advantages for root crops, such as cleaner roots, soil-

Institute of Medicinal Material in Viet Nam, 2000). free materials, compared with soil-based cultivation,

In the previous study, Ninh et al. (2006) reported the initial cost for the system and running costs are that selecting seeds based on the weight and specific very high (Soffer, 1985). Accordingly, the aeroponic gravity enhanced the root growth in Touki seedlings. system is often not economically applicable (Jensen Received Oct. 10, 2006 and Collins, 1985). Accepted Mar. 10. 2007 Drip irrigation system is the most popular system * Corresponding author 648 Mastudo, Matsudo city, Chiba 271-8510, Japan used in arid lands, to increase use efficiency [email protected] (Pruitt et al., 1989; Sezen et al., 2006). Furthermore, Ninh et al.: Effect of nutrient solutions in hydroponic systems on the growth of Touki plant 85

drip irrigation enhances yield because fertilizer is Growth conditions applied directly to active root zones (Hebbar et al., Aeroponic system 2004; Singandhupe et al., 2003). Accordingly, in many Four sets of aeroponic system (Fig. 1A) were instances, drip irrigation creates favorable conditions used, for one treatment each. The aeroponic system in the root zone for root growth. Kanuma soil, a consisted of: (i) an electric timer (H2F-D,OMRON),

granular form of volcanic ash soil free of the major (ii) a sub-timer (H3CR-F8N, OMRON), (iii) a pump (C- nutrient elements, as the growth medium is used to P60H, Hitachi), (iv)15 hydro-atomizing spray jets to easily control the desired level of nutrient solution. mist nutrient solution, (v) a tank with 200 L of recycled The main objective of the present study was to nutrient solution, (vi) a micro-clean effluent filtration examine the growth of Touki plants using different system, (vii) drain connectors, and (viii) a chamber concentrations of •gEnshi•h nutrient solution in the (bed). The bed was 3.6 m in length, 0.5m in width and aeroponic system and in Kanuma soil medium in the 0.6m in depth. The vertical walls and the bottom of the drip irrigation system, respectively. bed were covered with a black polythene film to shut light and the top of the bed was covered with 2 cm Materials and methods thick polystyrene foam. The plants were arranged into Plant materials 2 rows in the bed and inserted in holes of 2.5 cm in The experiments were conducted in a diameter. Each row contained 18 plants. The plant to located at the Faculty of Horticulture, Chiba University, plant distance in the row was 15cm and the distance Matsudo, Japan. between the two rows was 18 cm. The roots were Touki seedlings (seeds were purchased from hanged in the air and misted with the nutrient solution. Toyama Medicinal Plant Center in Toyama Prefecture, An on-off control system (2 minutes on and 4 minutes Japan) were transferred to pots (6 cm in diameter) off) was installed. To balance the minerals in the filled with the growth media (Tsuchitaro soil) containing nutrient solution, the nutrient solution was exchanged N:P2O5:K2O at rates of 120:1,000: 50 mg/L at pH 6.7. every two weeks during the experiment. Six-month-old seedlings were used for the experi- ments. The aeroponic experiment was carried out from Drip irrigation system March 15 to June 6, 2005 and the drip irrigation Four sets of drip irrigation system (Fig. 1B) were experiment was from May 2 to July 25, 2006. used. The set consisted of : (i) an electric timer (H2F

Fertilizer treatments

Four treatments with different concentrations of the •gEnshi•h nutrient solution (N:P:K:Ca:Mg) were adopted as follows: (i) standard •gEnshi•h solution (100% standard solution) was composed of 944.6 mg L-1

Ca(NO3)2.4H2O; 808.9 mg L-1 KNO3; 153.4 mg L-1

NH4H2PO4; 492.9 mg L-1 MgSO4, (ii) double concentra- tion of standard solution (200% standard solution), (iii) half a concentration of standard solution (50% standard solution), (iv) a quarter concentration of standard solution (25% standard solution). Electrical conductiv- ity (EC) values of the nutrient solutions were 3.7, 2.5,

1.5 and 0.95 dS/m (i.e. EC of tap water = 0.38 dS/m) for the 200%, 100%, 50% and 25% standard solutions, respectively. The pH was measured with a pH meter Fig,1 Schematic diagrams showing: (A) Sectional view of (Twin pH, Horiba Co., LTD, Japan), and adjusted with the aeroponic system (B) Sectional view of the drip 1N of H2SO4 at 5.5 - 6.0 every day. irrigation system.( In the four treatments, the same micro-nutrient 1) 200 L nutrient solution tank; (2) Pump;(3) Electric concentrations as those of the •gEnshi•h nutrient solution timer; (4) Sub-timer; (5) Electric counter; (6) Digital flowmeter; (7) Foam layer; (8) Plant; (9) Pipe connector were used. and spray jet; (10); (11)40 L nutrient solution tank; (12)Pipe connector and emitter 86 Jpn. J. Trop. Agr. 51(3) 2007

D,OMRON), (ii) a sub-timer (H3CR-A, OMRON), (iii) Data analysis an electric counter (H7CX, OMRON), (iv) a pump (C-P60S, Relative growth rate (RGR) and net assimilation

Hitachi), (v) a digital flowmeter (DIGMESA FMIG-HO- rate (NAR) was calculated according to equations 1-2

0C4), (vi) 30 emitters with drip tapes to drop the as following: nutrient solution, (vii) a tank with 40 L of nutrient RGR= {ln(W2) - ln(W1) }/(t2 - ti) eqn 1 solution, and 30 potted plants were transplanted in large pots (30 cm height and 16 cm diameter) in a row. NAR = (W2 - W1)•~{ln (LA2) - In (LA1) }/ Kanuma soil (5 mm in diameter; pH, 6.7), was { (LA2 -LA1) X (t2 - ti) } eqn 2 used as substrate to grow Touki plants in the drip irrigation system. Four rows of pots (each row was where Wis total plant dry weight, tis harvest time, LA allotted to each treatment) were placed on the bed is leaf area, subscripts 1 and 2 represent the two

(0.93 m•~8 m) in the greenhouse. The plant to plant harvest dates (intervals of 28 days). distance in the row was 30 cm and the distance All the data sets were analyzed by standard between two rows was 25 cm. The emitter attached to ANOVA. Means of growth parameters in the different the drip tape was placed in the center of the pot, where treatments were calculated with standard errors. the nutrient solution was absorbed directly by the Significant differences (P<0.05) between the treat- roots. The nutrient solution was pumped from each ments were determined using Tukey' test (HSD). tank and applied through the emitters in the pots. Results Fertilization was performed 2 times/day (8:00 am and

2:00 pm), at a rate of 20 ml of nutrient solution/pot Growth of Touki plants in nutrient solutions at each time during the first four-week period. Thereafter, different concentrations in the aeroponic system the fertilization was performed 3 times/day (8:00 am, Air temperature

12:00 am and 2:00 pm), at a rate of 30 ml/pot each The daily average values of the air temperature time. The drainage was not collected for recycling. ranged from 16.8•Ž to 25.2•Ž outside the bed, and from

The air temperature was measured at intervals of 15.3•Ž to 24.1•Ž inside the bed (Fig. 2 A) during the

30 minutes during the experiment. Thermometers were placed outside the bed (at 10 cm above the top of the plant) and inside the bed (at 5 cm under the bed) for the aeroponic system, and were placed outside the pot (at 10 cm above the top of the plant) for the drip irrigation system.

Plant samples

Ten plants each were sampled at the beginning and then every four weeks in each treatment. The leaf area per plant was measured with an automatic area meter (AAM-8 Hayashidenko Inc., Tokyo, Japan) and the root diameter was measured with a digital caliper

(0.01 -150 mm Code No 500 -110 SR 44, Mitutoyo,

Japan). The plant was divided into three parts (i.e., leaves, stems including petioles, and roots), dried at 70

•Ž for 48 hours in a convectional oven and weighed.

The dry leaves, stems and roots of the samples at 12 weeks after transplanting were chopped into small

pieces and ground using a Willey mill to pass a 1-mm

mesh sieve. The total carbon concentration (C) (% dry weight) and total nitrogen concentration (N) (% dry Fig. 2 Daily average value of air temperature in the weight) in the leaves, stems and roots were measured greenhouse: (A) In the aeroponic system and (B) In in 150 mg aliquots of samples, using a CN Corder the drip irrigation system during the experimental

(Model MT 700; Yanaco INC, Kyoto, Japan). period. Ninh et al.: Effect of nutrient solutions in hydroponic systems on the growth of Touki plant 87

experiment. root diameter of the plants grown in the 100%, 50% and 200% standard solutions were significantly higher than Growth parameters those of the plants grown in the 25% standard solution. (i) Leaf area At 12 weeks after transplanting, the highest value of The leaf area was affected by the concentrations the root diameter was 27.1 mm in the plants grown in of the nutrient solutions. At 12 weeks after transplant- the 100% standard solution, while the lowest value was ing, the leaf area in the plants grown in the 100% 19.7 mm in the plants grown in the 25% standard standard solution was significantly larger than that in solution (Fig. 3B). the plant grown in the other nutrient solutions (200%, (iii) Shoot dry weight 50% and 25% standard solutions). The leaf area in the At 12 weeks after transplanting, the shoot dry 200% and 50% standard solutions was not significantly weight was significantly higher in the plants grown in different (Fig. 3A). The lowest value of the leaf area the 100% standard solution than in those grown in the was obtained in the plants grown in the 25% standard 50%, 200% and 25% standard solutions (Fig. 3C). The solution (699.9 cm2 compared with 1632.7 cm2 in the significantly lowest value of the shoot dry weight was 100% standard solution). obtained in the plants grown in the 25% standard (ii) Root diameter solution. The shoot dry weight in the plants grown in From 8 weeks to 12 weeks after transplanting, the the 100% standard solution was 3 times higher than

Fig. 3 Effects of different concentrations of nutrient solutions on: (A) Leaf area; (B) Root diameter; (C) Shoot dry weight; (D) Root dry weight; (E) Total dry weight; and (F) Root/shoot ratio of Touki plants, at different times after transplanting in the aeroponic system. ErrorBar = SE, * I =HSD (5%). 88 Jpn. J. Trop. Agr. 51(3) 2007

that in the plants grown in the 25% standard solution. (iv) Root dry weight At 12 weeks after transplanting, the root dry weight was significantly higher in the plants grown in the 100% standard solution than in those grown in the 50%, 200% and 25% standard solutions (Fig. 3D). The lowest value of the root dry weight was obtained in the plants grown in the 25% standard solution (5.5 g plants compared with 14.7 g plant-1 in the 100% standard solutions). (v) Total plant dry weight At 12 weeks after transplanting, a significantly higher total dry weight was obtained in the plants grown in the 100% standard solution, compared with that in the plants grown in the other treatments. From 8 weeks to 12 weeks after transplanting, the growth rate, i.e., an increase in the total dry weight per plant, was the highest in the plants grown in the 100% standard solution (31.8 g plant-1 during 4 weeks), and the lowest in the plants grown in the 25% standard solution (9.0 g plant-1 during 4 weeks) (Fig. 3E). (vi) Root/shoot ratio Fig. 4 Effects of different concentrations of nutrient The root/shoot ratio of the plants grown in the solutions on: (A) Relative growth rate and (B) Net nutrient solutions with the different concentrations assimilation rate in Touki plants, at different times after transplanting in the aeroponic system. was not significantly different at 12 weeks after ErrorBar = SE, * I =HSD (5%). transplanting. The highest value of the root/shoot ratio was 0.55 in the plants grown in the 100% standard solution (Fig. 3F). were not significantly different among the nutrient (vii) Relative growth rate (RGR) solution concentrations; except for the C concentration RGR in dry weight increased from 4 weeks to 8 in root of the plants grown in the 50% standard solution weeks after transplanting and decreased from 8 weeks which was lower than that of plants grown in the other to 12 weeks after transplanting. From 8 weeks to 12 treatments (Fig. 5A). Among the organs, leaf showed a weeks after transplanting, the RGR values decreased higher C concentration than in the stem and root of the sharply in the plants grown in the 200%, 50% and 25% plants grown in the same nutrient solution. The C standard solutions. The highest value of RGR from 8 to concentrations were 38.1% in the leaf, 37.4% in the root 12 weeks was 51.0 mg mg-1 day-1 in the plants grown in and 34.0% in the stem of plants grown in the 100% the 100% standard solution. The lowest value of RGR standard solution. was 30.1 mg mg-1 day-1 in the plants grown in the 25% N concentration (% dry weight), in contrast to C, standard solution (Fig. 4A). was significantly affected by the nutrient treatments. (viii) Net assimilation rate (NAR) The N concentration increased with an increase in the From 8 weeks to 12 weeks after transplanting, the concentrations of the nutrient solutions. The N NAR values decreased in the plants grown in the 200%, concentrations in the leaf were 4.5%, 3.8%, 3.3% and 50% and 25% standard solutions, while a significantly 3.0% when the plants were grown in the 200%, 100%, higher value of NAR was observed in the plants grown 50% and 25% standard solutions, respectively. Among in the 100% standard solution. The NAR values were the organs, the N concentration in the leaf was higher 1.08 mg cm-2 day-1 and 0.6 mg cm-2 day-1 in the plants than that in the root and stem of the plants grown in grown in the 100% and 25% standard solutions, the same nutrient solution (Fig. 5B). respectively (Fig. 4B). Due to the changes in the N concentration, the (ix) C, N concentrations and C/N ratio in plant organs C/N ratio decreased with an increase in the The C concentrations in the leaf, stem and root concentrations of the nutrient solutions in leaf, stem Ninh et al.: Effect of nutrient solutions in hydroponic systems on the growth of Touki plant 89

ranged from 22.3•Ž to 31.3•Ž during the experimental

period (Fig. 2B).

Growth parameters (i) Leaf area From 4 weeks to 12 weeks after transplanting, the leaf area increased rapidly in the plants grown in the 100%, 200% and 50% standard solutions, while it increased slowly in the plants grown in the 25% standard solution. At 12 weeks after transplanting, a significantly higher leaf area was observed in the plants grown in the 100% standard solutions (767.9 cm2), compared with that in the plants grown in the 50% (550.0 cm2) and in the 25% standard solutions (401.9 cm2) (Fig. 6A). (ii) Root diameter Fig. 6B shows that at 12 weeks after transplanting, the root diameter of the plants grown in the 100% standard solution (21.7 mm) was significantly higher than that of the plants grown in the 50% (19.0 mm) and 25% standard solutions (16.2 mm). (iii) Shoot dry weight From 4 weeks to 12 weeks after transplanting, the shoot dry weight of the plants grown in the 100% and 200% standard solutions increased more rapidly than that of the plants grown in the 50% and 25% standard solutions. At 12 weeks after transplanting, the highest value of the shoot dry weight was 7.1 g in the plants grown in the 100% standard solution (Fig. 6C). (iv) Root dry weight At 12 weeks after transplanting, the root dry weight were significantly higher in the plants grown in Fig. 5 Effect of different concentrations of nutrient solutions in the aeroponic system on: (A) Carbon the 100% and 200% standard solutions than that in the concentration (% dry weight); (B) Nitrogen plants grown in the 25% standard solution. The root concentration (% dry weight) and (C) C/N ratio in dry weight in the plants grown in the 100% standard Leaf, stem and root of Touki plants at 12 weeks after solution was 49.1% higher than that in the plants grown transplanting. Error Bar = SE in the 25% standard solution (Fig. 6D). (v) Total plant dry weight At 12 weeks after transplanting, a significantly and root (Fig. 5C). The highest C/N ratio was found in higher total dry weight was obtained in the plants the plants grown in the 25% standard solution (14.2% in grown in the 100% standard solutions, compared with the stem). Among the organs, the C/N ratio in the that in plants grown in the 25% standard solution. From stem was higher than that in leaf and stem of plants 8 weeks to 12 weeks after transplanting, the growth grown in the same nutrient solution. rate, i.e., an increase in the total dry weight per plant, was significantly higher in the plants grown in the 100% Growth of Touki plants in nutrient solutions at standard solution than that in the plants grown in the different concentrations in the drip irrigation 25% standard solution. The increase in the total dry system weight per plant was 7.2 g plant-1 during 4 weeks in the Air temperature plants grown in the 100% standard solution, while it The daily average values of the air temperature was 4.5 g plant-1 during 4 weeks in the plants grown in 90 Jpn. J. Trop. Agr. 51(3) 2007

Fig. 6 Effects of different concentrations of nutrient solutions on: (A) Leaf area; (B) Root diameter; (C) Shoot dry weight; (D) Root dry weight; (E) Total dry weight; and (F) Root/shoot ratio of Touki plants, at different times after transplanting in the drip irrigation system. ErrorBar = SE, *I =HSD (5%).

the 25% standard solution (Fig. 6E). subjected to the other treatments (Fig. 7A). (vi) Root/shoot ratio (viii) Net assimilation rate (NAR) At 12 weeks after transplanting, the values of the From 4 to 8 weeks after transplanting, the NAR root/shoot ratio were not significantly different among values in the plants grown in the 100%, 50% and 200% the plants grown at different concentrations of the standard solutions were much higher than that in the nutrient solutions. The highest value of the root/shoot plants grown in the 25% standard solution. ratio (1.02) was obtained in the plants grown in the 25% From 8 weeks to 12 weeks after transplanting, the standard solution (Fig. 6F). NAR value in the plants grown in the 25% standard (vii) Relative growth rate (RGR) solution was higher than that in the plants subjected to From 4 weeks to 8 weeks after transplanting, the the other treatments (Fig. 7B). RGR value was the highest in the plants grown in the (iv) C, N concentrations and C/N ratio in plant organs 100% standard solution (35.8 mg mg-1 day-1) and the The C concentrations of the stem and root lowest in those grown in the 25% standard solution (9.4 decreased with an increase in the concentrations of the mg mg-1 day-1). There were few variations in the RGR nutrient solutions. The root C concentrations were values from 8 weeks to 12 weeks after transplanting; 37.8% and 36.5% for the plants grown in the 25% and RGR values in the plants grown in the 25% standard 100% standard solutions, respectively. Leaf C concentra- solution increased to the level of those in the plants tions were not significantly different among the Ninh et al.: Effect of nutrient solutions in hydroponic systems on the growth of Touki plant 91

Fig. 7 Effects of different concentrations of nutrient solutions on: (A) Relative growth rate and (B) Net assimilation rate in Touki plants at different times after transplanting, in the drip irrigation system. ErrorBar = SE, * I =HSD (5%).

concentrations of the nutrient solutions. Among the organs, the C concentration in the leaf was higher than that in the stem and root of plants grown in the same nutrient solution (Fig. 8A). Fig. 8 Effect of different concentrations of nutrient There was a significant increase in the N solutions in the drip irrigation system on: (A) concentrations of leaf, stem and root with an increase Carbon concentration (% dry weight); (B) Nitrogen in the concentrations of the nutrient solutions. The concentrations (% dry weight) and (C) C/N ratio in Leaf, stem and root of Touki plants at 12 weeks after highest concentration of N (3.4%) was found in the transplanting. plants grown in the 200% standard solution (Fig. 8B). Error Bar =SE. The C/N ratio of leaf, stem and root also decreased with an increase in the concentrations of the nutrient solutions (Fig. 8C). The highest C/N ratio Discussion (21.1%) was recorded in the stem of the plants grown in the 25% standard solution. Effect of different concentrations of nutrient

solutions on the growth of Touki plants.

Comparison of the growth parameters between The results of the present study showed that the culture in aeroponic system and drip irrigation use of •gEnshi•h nutrient solution at different concentra- system tions affected the growth of Touki plants. At low

The growth parameters (i.e. leaf area, root concentrations of the nutrient solutions (i.e., 50% and diameter, root, shoot and total dry weight, RGR and 25% standard solutions), the plants became stunted,

NAR) in plants grown in the aeroponic system were resulting in a small leaf area. Therefore, the plants much higher than those grown in the drip irrigation produced a smaller amount of dry matter (i.e., shoot, system during the experimental period. root and total plant dry weight) than those grown in 92 Jpn. J. Trop. Agr. 51 (3) 2007

the 100% standard solution, suggesting that the 25% Fig. 4B) than or equal to that in the 100% standard and 50% standard solutions can not be suitable to the solution (in the drip irrigation system, Fig. 7B), from 8 plant nutrient requirements. Dufour and Guerin (2005) to 12 weeks after transplanting. This led to a decrease also indicated that Anthurium andreanum Lind. grew in the dry weight (i.e. shoot, root and total dry weight) slowly in the low concentration of nutrient solution. at high concentrations of the nutrient solution,

Fig. 5B shows that the N concentration in the leaf indicating that the use of a nutrient solution with a decreased with the decrease of the concentration in high concentration (200% standard solution) was not the nutrient solution. Chapin (1980) reported that a suitable. These data corresponded well to the results low N concentration in the leaf tissue decreased the obtained by Park et al. (1999), who reported that photosynthetic rate. In our study, the low values of watermelon plants became stunted when grown in the NAR was obtained from the plants grown in the 50% 200% •gEnshi•h nutrient solution. and 25% standard solutions from 8 to 12 weeks after The standard solution of 100% is optimal for Touki transplanting in the aeroponic system (Fig. 4B). plants grown in both aeroponic and drip irrigation Scheible et al. (1997) and Steinbachova-Vojtfskova et al. system. (2006) reported that nitrogen is a component of the photosynthetic machinery, and CO2 assimilation depends Growth of Touki plants in the aeroponic and drip on the function of many proteins and enzymes in the irrigation systems photosynthetic systems. Therefore, N limitation led to In the aeroponic system, a mist of nutrient a decrease in growth. solution is frequently applied to the root zone of the In the drip irrigation system, from 8 weeks to 12 plants which may account for the higher growth rate weeks after transplanting, the RGR and NAR values compared with that of the plants grown in the other increased in the plants grown in the 25% standard hydroponic systems (Martin-Laurent et al., 1997). In solution, but were not changed or decreased in the agreement with these findings, our results showed that plants grown at higher concentrations of the nutrient the growth rate (in terms of RGR and NAR) of the solutions (i.e. 100% standard solutions) (Fig. 7A & B). plants cultured in the aeroponic system was higher However, the growth rate, i.e., the increase in the total than that of the plants cultured in the drip irrigation dry weight per plant, was significantly lower in the 25% system. However, secondary roots were developed standard solution than that in the plants grown in the much more in the drip irrigation system, than those in 100% standard solution (Fig. 6E). the aeroponic system as shown in Pictures 1 and 2. In On the other hand, at a high concentration of the addition, the values of the root/shoot ratio and root nutrient solution (i.e. 200% standard solution), although C/N ratio were higher in the plants grown in the drip the N concentration in the leaf tissue was higher, the irrigation system than those in the plants grown in the photosynthetic rate in terms of NAR in the 200% aeroponic system. The high root/shoot ratio is an standard solution was lower (in the aeroponic system, indication of better growth balance for root, which is

Picture 1 Roots of Touki plants in the aeroponic Picture 2 Roots of Touki plant in the drip irrigation

system at 12 weeks after transplanting system at 12 weeks after transplanting

(100% standard •gEnshi•hsolution). (100% standard •gEnshi•h solution). Ninh et al.: Effect of nutrient solutions in hydroponic systems on the growth of Touki plant 93

used for medicinal purposes. Martin-Laurent, E, S.-K. Lee, F-Y. Tham, J. He, H. G. Diem and P.

Durand 1997. A new approach to enhance growth and nodulation of Acacia mangium through aeroponic culture. Prospects for application of aeroponic and drip Biol. Fertil. Soils 25: 7-12. irrigation systems in Viet Nam National Institute of Medicinal Materials 2000. Medicinal plants

Based on the effect of nutrient solution concentrations resource of Viet Nam. Technologies and Sciences Publishers (Ha Noi) 415-603.* on the growth of the Touki plants, the present results Ninh, T. P., Nojima, H. and Tashiro, T. 2006. Effect of seed indicated that the 100% standard•gEnshi•hnutrient selection based on seed weight and specific gravity on seed solution is the optimum nutrient solution for growing germination and seedling emergence and growth in Angelica acutiloba Kitagawa. Jpn. J. Trop. Agr. 50:154-162. Touki plants. Pagliarulo, C. L. and Hayden, A. L. 2000. Potential for green In several medicinal plants, high productivity may house aeroponic cultivation of medicinal root crops. Proceedings of the 30th National Agri. Plastics Congress, not be positively correlated with the quality (i.e. Amer. Soc. For . San Diego, California 23- 26 therapeutic potential) (Hassan et al., 2005). Therefore, February. ligustilide concentration in the roots of Touki plants Park, S. G., B.-S. Lee, J: Y. Cho, J.-S. Ann and S.-J. Chung. 1999. Effects of ionic strength of nutrient solution on the growth should be determined as an index of the quality for and fruit quality of 'Mudeungsan' watermelon (Citrullus medddicinal plants. The present results indicated that the lanatus Thunb.) grown in rockwool. Acta Hort. 483:133-145. growth of Touki plants, especially the root growth, was Pham, V. Y. 2000. Research, selection and establishment the more vigorous in the aeroponic system than in the drip production procedure for Angelica acutiloba Kitagawa acclimatized to Northern of Viet Nam. Agri. Ph.D.thesis. irrigation system. However, the secondary roots are Institute of Agricultural Science and Technology (Ha Noi) 28- mainly used as raw materials for medicine in Viet Nam 31.** Pruitt, W. 0., Fereres, E., Martin, P. E., Singh, H., Henderson, D. (Pham, 2000) and the culture in the drip irrigation W., Hagan, R. M., Tarantino, E. and B., Chandio 1989. system stimulated the development of secondary roots Microclimate, evapotranspiration, and water use efficiency and enhanced the root/shoot ratio than culture in the for drip and furrow irrigated tomatoes. International Conference on Irrigation and Drainage (ICID) 12th Congress aeroponic system. Therefore, the drip irrigation system 38: 367-393. can be recommendable as an advanced culture system Scheible, W. R., Gonzalez-Fontes, A. Lauerer, M. Muller-Rober, B. for the Touki plants in Viet Nam. Caboche, and M. Stitt 1997. Nitrate acts as a signal to induce organic acid metabolism and repress starch metabolism in References . Plant Cell 9: 783-798. Sezen, S. M., A. Yazar, and S. Eker 2006. Effect of drip irrigation

Burgess, T, McComb, J. and Hardy, G. 1998. Influence of low regimes on yield and quality of field grown bell pepper.

oxygen levels in aeroponics chambers on eucalypt roots Agricultural Water Management 81:115-131. infected with Phytophthora cinnamomi. Plant Dis. 82: 368- Singandhupe, R. B., Rao, G. G. S. N., Patil, N.G., and

373. Brahmanand, P. S. 2003. studies and irrigation Chapin, E S. 1980. The mineral nutrition of wild plants. Annu. scheduling in drip irrigation system in tomato crop

Rev. Ecol. Syst.11: 233-260. (Lycopersicon esculentum L.). Europ. J. Agronomy 19: 327- Dufour. L. and V. Guð¥rin 2005. Nutrient solution effects on the 340. development and yield of Anthurium andreanum Lind. in Soffer, H. 1985. Current research and developments. In:

tropical soilless conditions. Scientia Horticulturae 105: 269- Worldwide: State of the Art in Soilless Crop 282. Production (A. J. Savage Ed.). International Center for Gontier, E., A. Clð¥ment, T. L. M. Tran, A. Gravot, K. Lið¤vre, A. Special Studies, Honolulu, HI. 123-130.

Guckert and E Bourgaud 2002. Hydroponic combined with Steinbachovð•-Vojtið´kovð•, L., E. Tylovð•, A. Soukup, H. Novickð•, 0.

natural or forced root permeabilization: a promising technique Votrubovð•, H. Lipavskð•, and H. •¬ð©•¬kovð• 2006. Influence of for plant secondary metabolite production. Plant Science nutrient supply on growth, carbohydrate, and nitrogen

163: 723-732. metabolic relations in Typha angustifolia. Environmental and

Hassan, A., P. Ljubuncic, I. Portnaya, 0. Said, U. Cogan and A. Experimental Botany 57: 246-257. Bomzon 2005. Fertilization-induced changes in growth Yomo, T, C. Hasegawa, M. Minami and M. Sugino 1998a.

parameters and antioxidant activity of medicinal plants used Production of medicinal plants by hydroponics (Part 4) in traditional Arab medicine. eCAM 2: 549-556. Selection of hydroponic system suitable for growth of Hebbar, S. S., B. K. Ramachandrappa, H. V. Nanjappa and M. Angelica acutiloba Kitagawa. Journal of Society of High

Prabhakar 2004. Studies on NPK drip fertigation in field Technology in Agriculture 10:156160.***

grown tomato (Lycopersicon esculentum Mill.). Europ. J. Yomo, T, C. Hasegawa, M. Minami and M. Sugino 1998b. Agronomy 21:117-127. Production of medicinal plants by hydroponics (Part 5)

Jensen, M. H. and W. L. Collins 1985. Hydroponic vegetable Effects of substrates on initial growth of Angelica acutiloba

production. Hort. Rev. 7: 483-558. Kitagawa plants cultivated by Ebb & Flow system. Journal of Lissner, J., I. A. Mendelssohn and C. J. Anastasiou 2003. A Society of High Technology in Agriculture 10:161-165.*** method for cultivating plants under controlled redox (*In Vietnamese with English Summary, In Vietnamese, ***In intensities in hydroponics. Aquatic Botany 76: 93-108. Japanese with English Summary) 94 Jpn.J.Trop.Agr.51(3)2007

噴 霧 耕 栽 培 と点 滴 灌 漑 栽 培 に よ るArcegelica acutiloba Kitagawaの 生 育 に 及 ぼ す 培 養 液 濃 度 の 影 響

Ninh Thi PHIP・ 野 島 博*・ 田 代 亨

千葉大学園芸学部

要 約 ベ トナ ム に お い てAngelica acutiloba Kitagawa‘ トウ キ’ は土 耕 で 栽 培 され て い る.こ の 植 物 へ の 施 肥 は 収 量 に大 き な 影 響 を 及 ぼ す が,最 適 の 施 肥 法 に 関 す る研 究 は 不 十 分 で あ る.本 研 究 で は,園 試 処 方 の 均 衡 培 養 液 の100%(標 準), 200%,50%,25%の4水 準 濃 度 で 噴 霧 と 点 滴 灌 漑 を用 い て 養 液 栽 培 し,生 育 に 及 ぼ す 影 響 を 比 較 検 討 し た.噴 霧 耕 栽 培 で は 根 部 周 辺 に 培 養 液 を噴 霧 し,2005年3月15日 か ら同 年6月6日 ま で,点 滴 灌 漑 栽 培 で は2006年5月2日 か ら 同 年7月25日 まで トウ キ を栽 培 し た.移 植 後12週 間 目 に お い て,ト ウ キ の 生 育(葉 面 積,根 の 直 径,部 位 別 乾 物 重)は 噴 霧 耕 栽 培 で は 100%>50%>200%>25%,点 滴 灌 漑 方 式 で は100%>200%>50%>25%の 順 序 で 高 い値 を 示 し,両 方 式 と も に 園 試 処 方 の 100%標 準 培 養 液 が 優 れ て い た.植 物 体 の 生 育,特 に根 部 は 点 滴 灌 漑 栽 培 よ り も 噴 霧 耕 栽 培 の 方 が 高 か っ た.し か し,根 と茎 葉 の 比,炭 素 と窒 素 の 比 は 点 滴 灌 漑 栽 培 の 方 が 明 ら か に 高 か っ た.ま た,二 次 根 の 発 達 は 点 滴 灌 漑 栽 培 の 方 が非 常 に 優 れ て い た.ベ トナ ム に お い て トウ キ の 二 次 根 は 生 薬 の 原 料 と な る.以 上 の こ と か ら,総 合 的 に考 え る と ベ トナ ム に お い て 有 益 な 栽 培 方 式 と し て 点 滴 灌 漑 方 式 を 用 い る こ と が推 奨 され る. キ ー ワ ー ド:ト ウ キ,無 機 栄 養 素,薬 用 植 物,養 液 栽 培

*Corresponding author

〒271-8510松 戸 市 松 戸648 [email protected]