Effect of Saline Concentrations on Growth of Melon Cultivated under Protected Environment

Adequate knowledge on management of soilless cultivation systems using substrate arouses great interest when one mentions its usage for commercial purposes. The objective of this study was to evaluate the biomass production and distribution of melon crop (Cucumis melo var. inodorus) cultivated in raw rice husk with leach recirculation, as a function of three different saline concentrations of the nutrient solution. A standard solution of 2.3 dS m(-1) electrical conductivity (100% saline concentration) was used as a reference treatment. The concentration of the remains treatments was determined based on the standard solution, with reduction and increase of 25% in the macronutrients amount corresponding to electrical conductivities of 1.9 and 2.9 dS m(-1), respectively. Sowing was done on 17th February 2003. Seventeen days after sowing, plants were transferred to polyethylene bags containing 13 L of raw rice husk at the density of 1.69 plants per square meter. From the data of dry and fresh matter accumulated at 62 days after setting, biomass production and distribution among the different plant parts were established. The lowest saline concentration of the nutrient solution (1.9 dS m(-1)) promotes a similar plant growth to the one observed at higher concentrations. Thus, it can be indicated for melon cultivation in raw rice husk during autumn crop-season. Raw rice husk can be used as substrate in soilless production systems with leaching recirculation.