Evaluation of treated wastewater for the production of Syngonium podophyllum

Abstract

The objective of this research was to evaluate the use of reclaimed water for the irrigation of nursery and floral crops. On the first phase of the research, a survey of several sources of reclaimed water was done. The quality of waters surveyed differed widely. Total soluble solids (salinity) of waters surveyed was found in the range of 438 mg/l and 1978 mg/I. Therefore, classification of reclaimed water according to its salt content varied from extremely saline to non-saline. Trace elements did not represent a risk in any of the waters. In the second phase of the research, 5 combinations of reclaimed water with reverse osmosis water were evaluated on the irrigation of Syngonium podophyllum. There was a significant difference between treatments for the variables plant height, width, growth index, and quality. Fresh weight and dry weight of treatments were not significantly different. The control (100% reverse osmosis water) was the treatment with the highest growth yields. Treatment with the lowest growth yields was 1 00% reclaimed water. Electrical conductivity and pH of irrigation solution were significantly different within treatments and also varied overtime. In the third phase of the research, a 1: 1 combination of reclaimed water:reverse osmosis water with different fertility regimes was evaluated on the irrigation of Syngonium. Treatments were 1 00 mg/l N, 200 mg/l N, 300 mg/l N, and 400 mg/l N. Electrical conductivity of treatments at the beginning of the experiments were 1. 1 8 mS/cm, 1.87 mS/cm, 2.37 mS/cm, and 3.20 mS/cm. Results show significant difference for all parameters evaluated (plant height, width, growth index, and quality). Plants irrigated with the lowest fertility regime had the highest growth yield averages. Averages decreased as the fertility regime increased. In the last phase of the research, coliform levels were evaluated in growing medium of Syngonium plants and in the irrigation solution. Although reclaimed water used, coming from secondary effluent, was not disinfected, coliform colonies diminished to undetectable levels in a relatively short period of time (1-14 days).