Tomato Production in Subirrigated Systems Y. Tüzel1, I.H.Tüzel2, A. Gül1, G.B. Oztekin1 and F. Ucer 1 Ege University, Faculty of Agriculture Depts. of 1Horticulture and 2Agricultural Structures and Irrigation, Bornova/Izmir Turkey Keywords: subirrigation, substrate, root volume, water use efficiency (WUE) Abstract Simplified subirrigated system including strophor containers and a smart ® valve controlling the entry of water to the reservoir (modified Auto-pot system) was tested in tomato production during the years of 2004 and 2005 in order to determine the effects of different substrates and container volumes on yield, quality and water consumption. In the spring season of 2004, perlite, zeolite and volcanic tuff were compared 2 in the system. The highest total yield was obtained from perlite as 11.3 kg/m . The following autumn (2004) and spring (2005) seasons the volume of the containers as 6, 9, 12 and 15 litres perlite per plant was compared in terms of yield, fruit quality and water use efficiency. There were no significant differences among the treatments in both growing seasons and the total yields in autumn and spring seasons changed between 8.48 – 2 11.24 and 9.74 – 10.18 kg/m respectively. INTRODUCTION Soilless culture is one of the strategies to replace MeBr. However, there is a need for a system with low cost operation and simple enough technology for water and fertilizer use, suiting farmers’ dependence on capital spending and knowledge and also considering consumers’ expectations for high quality and safe product, with less environmental impact and cost reduction. In subirrigated systems, nutrient solution is not leached or discharged into the environment (Elia et al., 2003). Compared to the traditional ones subirrigated systems have several advantages in terms of water and fertilizer saving, uniformity of nutrition, labor efficiency (Uva et al., 1998) and self-scheduling (Fah, 2000). Those systems are proposed mainly in the pot plant production due to the short growing cycle and low water and nutrient requirements (Molitor, 1990; Nelson, 1990; Dole et al., 1994). The Auto-pot system, a patented hydroponic technique, uses capillary action in the substrate to deliver solution to the plant roots (McIntyre and McRae, 2005). It is a fully automatic, empowered watering and feeding system capable of supplying the needs of individual plants (Fah, 2000). In the modified systems the number of plants grown in a container is increased. The purpose of this study was to test simplified sub-irrigated system in tomato production comparing substrates and substrate volumes and to determine yield, fruit quality parameters and water use efficiencies. MATERIALS AND METHODS This study was carried out in a polyethylene covered, non-heated high tunnel at the Faculty of Agriculture in Ege University between 2004 and 2005. The tested system had strophor containers (120 x 25.5 x 21 cm) and each one had a smart valve controlling the entry of water to the reservoir (modified auto-pot system). Nutrient solution was provided via a tank (30 litres) connected to three containers. Water and nutrient was supplied when the valve was opened to allow the solution to enter the bottom of the container to a pre determined and pre set depth (usually 3.5 cm). Then valve closed and did not permit per mit further entry of solution until the original supply had been th
Proc. VIII IS on Protected Cultivation in Mild Winter Climates Eds.: A. Hanafi and W.H. Schnitzler Acta Hort. 747, ISHS 2007
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conveyed from the solution chamber to the pot and consequently to the plant. Absorption was achieved by capillary action that naturally occurred in the substrate. Once the solution had been absorbed to the extent that the solution film under the valve had gone, the valve re-opened to supply water and nutrient to the container (Fah, 2000). In the spring season of 2004, perlite, zeolite and volcanic tuff were compared in the system. Planting date of cv. ‘Durinta’ seedings were 24 th March 2004 with a plant density of 3.48 plants/m 2. Plant root volume was 5 litres per plant. The following autumn (2004) and spring (2005) seasons experiment was redesigned and perlite was used as growing medium according to the results obtained from the first experiment in spring 2004. The heights of the containers were increased in order to compare different volumes of the plant roots namely 6 (control), 9, 12 and 15 litres per plant. The planting dates were 03 September 2004 and 04 March 2005 in autumn and spring seasons, respectively. Water and nutrient requirements were supplied with a complete nutrient solution with a composition of (mg L -1) N 210 (240), P 40, K 250 (300), Ca 150, Mg 50, Fe 2, Mn 0.75, B 0.4, Zn 0.50, Cu 0.10 and Mo 0.05 (Day, 1991). The concentrations shown in the brackets of N and K were the increased doses used after the fruit setting at the 3rd truss. The concentration of Ca was 20 mg L -1 because level of Ca in tap water was found as high as 130 mg L -1. Crop development was terminated at 8 th truss in both seasons. Water consumption was calculated according to the amount of solution used in the system. The amount of total soluble solids (TSS,%) (Hortwirth, 1960), EC and pH of fruit juices, titratable fruit acidity (TA, mval/100 ml fruit juice) (Joslyn, 1970), total dry matter (DM,%) and vitamin C (Morell, 1941) were determined, as well. Roots were sampled at the end of growing season 2004 and 2005. Perlite was washed off the roots with top water. Root length and dry weight were determined. The experimental design was randomized parcels with three replicates. RESULTS AND DISCUSSION Effects of Substrates The effect of substrates on total yield was found significantly different. Among the tested substrates perlite gave the highest yield with 11.29 kg/m 2 (Table 1). Fruit quality parameters, namely dry matter content, titratable acidity, EC and pH of fruit juice and vitamin C content did not show any significant difference excluding total soluble solids. Water consumption of the plants grown in perlite was the highest. It was 9 and 24% higher in perlite compared with zeolite and tuff respectively. On the other hand the values of WUE for each substrate were almost the same (Table 2) due to the difference in yield. In the sub-irrigated system there is a continuous capillary movement of nutrient solution. Water and nutrient uptake is dependent the quantity and activity of root system (Gosiewski and Skapski, 1984). Substrate has a crucial role for the root development and to provide water, air and nutrient elements. Among the substrates perlite is accepted to be one of the most appropriate to use in sub-irrigated systems due to the higher water absorption (Elia et al., 2003). Effects of Substrate Volumes 1. Yield. In both growing seasons the effect of substrate volumes on total yield were found insignificant. While the total yield changed between 8.48 and 11.25 kg/m 2 in autumn, it was between 9.74 and 10.18 kg/m 2 in spring. Other parameters related to yield, namely total fruit number, average fruit weight and non marketable fruit ratio did not show any significant differences according to the tested substrate volumes (Tables 3 and 4). 2. Fruit Quality. Quality parameters were measured in the fruit samples taken and analyzed at the mid of growing season. In autumn season tested substrate volumes did not
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effect fruit titratable acidity, total soluble solids, dry matter content and EC and pH of fruit juice, where vitamin C changed significantly according to the treatment. The highest vitamin C was found in the substrate volume of 6 litres per plant (Table 5). In spring growing season the effects of substrate volumes on TA, vitamin C, EC and pH of fruit juice were found significant. The highest TA and fruit juice EC were obtained from the fruits harvested from the plants grown in the substrate volume of 6 L/plant. pH of fruit juice and vitamin C were the lowest in 12 L/plant (Table 6). 3 3. Water Consumption. Water efficiencies changed between 23.53 and 26.7 kg/m in 3 autumn and 45.36 and 52.99 kg/m in spring growing season (Table 7). 4. Root Growth. Although in autumn tested substrate volumes did not affect root length, in spring season root length of the plants increased with substrate volumes in both seasons. As a function of root growth, ratio of dry weight was significantly affected by the treatments. In both seasons, the highest values were recorded in the plants grown in 15 L/plant (Table 8). This result is in accordance with the result of Dosselaere et al. (2003) who indicate the more roots were found in the bigger pots, with the smallest pots limiting root growth and development the most. Thick roots were not found in the smallest pots and the roots in these pots were significantly shorter. ACKNOWLEDGEMENTS Supported by the European Union INCO Med 2 Project (ICA3-CT-2002–10020). Literature Cited Day, D. 1991. Growing in perlite. Grower Digest no.12, Grower Pub. Ltd., London, 36pp. Dole, J.M., Cole, J.C. and Broembsen, S.L. 1994. Growth of Poinsettias, nutrient laeching, and water-use efficiency respond to irrigation methods. HortSci. 29:858– 864. Dosselaere, N., Araya, M. and De Waele, D. 2003. Effect of pot volume on root growth, Radopholus similis reproductive potential and its damage on bananas. The International Journal on Banana and Plantain: Info Musa 12(1):17–21. Elia, A., Parente, A., Serio, F. and Santamaria, P. 2003, Some aspects of the trough bench system and its performance in cherry tomato production. Acta Hort., 614:161–166. Fah, J. 2000, Hydroponics made easy–2nd edition, e -book, (http://www.autopot.com.au/). Gosiewski, H. and Skapski, H. 1984. Fertilization of greenhouse tomatoes grown in subirrigation method. Acta Hort. 145:149–163. Hortwirth, W. 1960. Official Methods of Analysis A.O.A.C. Chapter 29. Sugars and Sugar Products. A.O.A.C. Benjamin Franklin Station. Washington, 4D.C. Joslyn, M.A. 1970. Acidimetry. p.404–439. In: M.A. Josly (ed.), Methods in Food Analysis-Academic Pres-London. McIntyre, A. and McRae, T. 2005. Introduction of new technology into hydroponic tomato growing at the farm level – A case study in collaborative research. Acta Hort. 672:241–247. Molitor, H.D. 1990. The European perspective with emphasis on subirrigation and recirculation of water and nutriets. Acta Hort. 272:165–173. MoreIl, S.A. 1941. Rapid Photometric Determination of Ascorbic Acid in Plant Materials. Ind. Eng. Chem. Analy. 13:793. Nelson, P.V. 1990. Developing root zone management strategies to minimize water and fertilizer waste: the United States perspective with emphasis on surface applied noncirculated system. Acta Hort. 272:175–185. Uva, W.L., Weiler, T.C. and Milligan, R.A. 1998. A survey on the planning and adoption of zero runoff subirrigation systems in greenhouse operations Hort. Sci. 33:193–196.
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Tables
Table 1. Changes of yield and fruit quality parameters according to substrate. Yield Substrate (kg/m2) Perlite 11.29 a Tuff 8.62 b Zeolite 9.35 b
DM (%) 11.89 11.89 10.44
TA (mval/100 ml) 8.20 8.97 9.01
TSS (%) 5.30 b 6.35 a 5.35 b
EC (dS/m) pH 5.59 3.94 5.41 3.96 5.79 3.89
Table 2. Water consumptions and WUEs of tested substrates.
Substrate Perlite Zeolite Tuff
Water consumption (L/plant) 146.13 120.85 111.11
WUE (kg/m3) 22.2 22.2 22.3
Table 3. Yield related parameters in autumn growing season.
6 L/ plant 9 L/ plant 12 L/ plant 15 L/ plant
Total yield (kg/m2)
Total number (no/m2)
Ave. fruit weight (g)
Non marketable fruits (%)
10.35 9.39 8.48 11.24
125.05 106.95 115.54 115.31
82.64 83.45 82.49 92.46
12.13 14.65 11.82 14.65
Table 4. Yield related parameters in spring growing season.
6 L/ plant 9 L/ plant 12 L/ plant 15 L/ plant
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Total Total Ave. fruit Non yield number weight marketable 2 2 (kg/m ) (no/m ) (g) fruits (%) 9.74 147.32 62.86 29.31 9.44 143.03 62.80 19.35 9.61 127.60 71.79 12.69 10.18 131.78 71.23 14.40
vit C (mg/100 ml) 7.13 7.94 6.96
Table 5. Fruit quality in autumn.
6 L/plant 9 L/ plant 12 L/ plant 15 L/ plant
TA (mval/100ml) 5.62 5.83 5.79 5.59
TSS (%) 4.60 4.33 4.30 4.23
DM (%) 5.62 5.84 5.79 5.65
EC (dS/m) 5.63 5.57 5.49 5.50
TSS (%) 5.87 5.90 5.33 5.17
DM (%) 7.11 6.93 6.85 6.22
EC (dS/m) 6.35 ab 6.48 a 6.12 bc 5.93 c
pH 4.56 4.62 4.60 4.61
Vit. C (mg/100ml) 18.73 a 15.54 b 16.33 ab 16.91 ab
Table 6. Fruit quality in spring.
6 L/plant 9 L/ plant 12 L/ plant 15 L/ plant
TA (mval/100ml) 9.69 ab 9.95 a 8.78 ab 8.36 b
pH 4.37 a 4.34 a 4.26 b 4.33 a
Vit. C (mg/100ml) 13.78 a 13.38 ab 11.56 b 13.78 ab
Table 7. Water consumptions and WUEs of tested substrate volumes.
6 L/plant 9 L/ plant 12 L/ plant 15 L/ plant
Water consumption (L/plant) Autumn Spring 57.0 107.8 56.9 106.1 52.4 98.5 62.6 107.8
WUE (kg/m3) Autumn Spring 50.85 25.76 46.35 25.39 45.39 27.81 50.80 26.91
Table 8. Root length and dry matter content.
6 L/plant 9 L/ plant 12 L/ plant 15 L/ plant
Length (cm) Dry weight (%) Autumn Spring Autumn Spring 30.3 26.7 b 14.9 b 16.6 b 31.5 28.5 b 15.7 b 19.2 b 31.5 32.0 ab 18.5 ab 19.7 b 33.0 38.3 a 20.9 a 30.2 a
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