Response of New Guinea Impatiens to Various Water Qualities in a Subirrigation System

With the rising concern for the environment and an increase in governmental regulation, greenhouse growers must find alternative methods for irrigation that will avoid ground and surface water contamination. Subirrigation is one of these alternatives, but subirrigation is more sensitive to water quality than traditional systems and many growers are faced with poor water quality. This experiment tested seven different water sources from across the state of Texas. Each source was replicated twice using New Guinea impatiens `Illusion'. Leaf count, plant height, and plant width were measured at 2-week intervals. Plants were harvested at 8 weeks and measured for shoot fresh weight, shoot dry weight, and overall quality. Electrical conductivity of the upper, middle, and bottom layers of the container medium was measured. Compared to the reverse osmosis control, fresh weight was reduced by 12% to 30%, average leaf number by –7% to 56%, quality evaluation by –8% to 61%, average width by –5% to 27%, and the average height by 8% to 34%. The results will be explained based on differences in analysis of the various water and media samples.