Response of Three Potato Cultivars Grown in a Novel Aeroponics System for Mini-Tuber Seed Production

Response of Three Potato Cultivars Grown in a Novel Aeroponics System for Mini-Tuber Seed Production J. Mateus-Rodríguez Corporación Colombiana de Investigación Agropecuaria Centro de Investigación Tibaitatá Km 14 vía Bogotá Mosquera Colombia

S. de Haan, I. Barker and C. Chuquillanqui International Potato Center Germplasm Enhancement and Crop Improvement Crop Management Division Av. La Molina 1895 La Molina, Lima 12 Peru

A. Rodríguez-Delfína Universidad Nacional Agraria La Molina Centro de Investigación de Hidroponía Av. La Molina s/n Lima 12 Peru

Keywords: Solanum tuberosum L., soilless culture, hydroponics, seed potato Abstract The International Potato Center (CIP) has recently developed and promoted mini-tuber production based on a novel, rustic and publically available aeroponics system. The technology is proposed as an alternative to conventional systems of prebasic seed (mini-tuber) production that use soil-based substrates requiring bromide for sterilization. Previous research has shown that the aeroponics technology is potentially efficient for specific potato cultivars. The overall objective of this study was to evaluate plant growth and mini-tuber production of three potato cultivars grown in an aeroponics system under greenhouse conditions at CIP’s experimental station in La Molina, Lima (Peru). The study was conducted between August 2008 and April 2009. A randomized complete block design with three replications was used, where the cultivars were the treatments. Measurements on tuberization, senescence, plant height and yield were recorded after transplanting. Significant differences between treatments were encountered for days till tuberization, plant height, and tuber yield. The highest number of tubers per plant was registered for the ‘Chucmarina’ cultivar, followed by ‘Serranita’ and ‘Yana Imilla’ with 71.7, 56.2 and 30.6 mini-tubers per plant, respectively. Tuber yield per plant ranged from 197.6 to 860.2 g per plant. Average tuber weight ranged from 6.3 to 12.1 g per minituber. Harvests were conducted every 20 days. An ample variability between cultivars exists as regards their response and production in an aeroponics system under uniform conditions. Results showed that the aeroponics system is a viable technological alternative for the potato mini-tuber production component within a potato tuber seed system. INTRODUCTION Typically potato (Solanum tuberosum L.) mini-tuber production initiates with the multiplication of virus-free, in-vitro plantlets in micro-propagation laboratories. Plantlets released from the laboratory are conventionally transplanted into beds or pots with sterilized media under greenhouse conditions in order to adapt the plants to the new micro-environment and to maintain their health status. The mini-tuber production rate of substrate-based greenhouse systems is relatively low and therefore has a negative influence on the seed’s production costs (Hidalgo et al., 1999). In addition, for media disinfection, the conventional systems require the use of toxic products such as methyl bromide with a negative impact on the environment (Gullino et al., 2003); or alternatively, the use of steam sterilization, but with a consequent higher fuel cost (Otazú, 2008). Among the technological alternatives used to substitute conventional systems for a

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Proc. II IS on Soilless Culture and Hydroponics Eds.: F.C. Gómez-Merino et al. Acta Hort. 947, ISHS 2012

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mini-tuber production, hydroponic systems are a good tool, and can obtain higher yields combined with superior phytosanitary quality (Boersig and Wagner, 1988; Wan et al., 1994; Muro et al., 1997; Rolot and Seutin, 1999; Rolot et al., 2002). Aeroponics is a novel technique that uses a hydroponics growing system where the plant roots are suspended in a dark enclosed chamber and sprayed with a nutrient solution as a fine mist (Christie and Nichols, 2004). This technique is used for the production of different vegetables, such as lettuce (He and Lee, 1998), tomato (Cho et al., 1996) and cucumber (Park et al., 1997). There are experiences with aeroponics potato mini-tuber production in Korea (Kang et al., 1996; Kim et al., 1997, 1999), Spain (Ritter et al., 2001; Farran and Mingo-Castel, 2006), Sri Lanka (Nugaliyadde et al., 2005), India and China. The International Potato Center (CIP) has also been promoting mini-tuber production using an aeroponics system under Andean highland conditions at 3200 m a.s.l. (Otazú and Chuquillanqui, 2007). The objective of the study here reported was to evaluate the plant development and yield of mini-tubers of three potato cultivars grown under an aeroponics system. MATERIALS AND METHODS The experiment was carried out at the CIP experimental station, La Molina, Lima (12°4’34”S; 76°56’46”W, altitude 244 m a.s.l.), from August 2008 to April 2009 (wintersummer conditions). The experiment was conducted under a “chapel” type non-climatized greenhouse measuring 30×12×8 m. The genotypes studied were two improved cultivars from CIP’s breeding program, released by Instituto Nacional de Innovación Agraria (INIA) from Peru, with a significant genetic weighting of S. tuberosum spp. andígena: ‘Chucmarina’ (INIA 310) and ‘Serranita’ (INIA 309), and a native cultivar from southern Peru called ‘Yana Imilla’. Under field conditions, the vegetative cycles of these cultivars are 120-150 days for ‘Chucmarina’ and ‘Serranita’, and 155-160 days for ‘Yana Imilla’. The plants were grown under the following environmental conditions (average values): Photosynthetically Active Radiation (PAR) 138.33 μmol/m2/s1 (winter) and 390.31 μmol/m2/s (summer); temperature range: 21.7°C max. and 15.7°C min. (winter); and 33.8°C max. and 23.3°C min. (summer); day and night temperatures: 20.2 and 17.2°C (winter) and 31.2 and 25.9°C (summer), respectively; relative humidity 80.1% (winter) and 66.6% (summer). The experimental design was a randomized complete block design with three replications; each container represented one block per replication, and the treatments were the cultivars. The analysis of variance was performed with the R statistical program (R Development Core Team, 2010). The media comparison was made with the Tukey test for P