Electrical conductivity and plant spacing on baby leaf table beet and lettuce production

Baby leaf market and production systems are beginning in Brazil. Some of the few hydroponically growers are adapting the nutrient film technique (NFT) system in their farms, however without the necessary knowledge, provided by research, for that. Thus, the aim of this research work was to evaluate the effect of electrical conductivity of nutrient solution and space between plants on table beet and lettuce for baby leaf production in NFT hydroponic system. Two independent experiments were carried out, from December 2011 to March 2012, with table beet and lettuce in a greenhouse of 126 m(2), at Northeast Paulista field station of Paulista Agency of Agribusiness Technology in Mococa, Sao Paulo state, Brazil. The experimental design was a split plot with randomized blocks replicated four times. The main treatment was composed of different electrical conductivities of the nutrient solution (0.4, 0.8, 1.2 and 1.6 dS/m) and the secondary treatment consisted of different spacings between plants (2.5, 5.0 and 10.0 cm) for both species. Harvest was carried out when leaves of each specie reached length of approximate 15.0 cm. Higher yields of 5.5 and 3.1 kg/m(2) were obtained with 1.6 and 1.4 dS/m for table beet and lettuce, respectively. The space between plants of 2.5 cm promoted greater yields of 4.2 and 4.9 kg/m(2) for table beet and lettuce, respectively.