2018 ASHS Annual Conference

Ornamental plants are an integral part of landscapes, and maintaining their visual quality is imperative to the their success. The premium placed on fresh water as a valuable resource makes it increasingly more difficult to plant ornamentals in urban areas or other areas where water scarcity is common. As high quality water becomes scarcer and more valued it is important to know which ornamental plants can tolerate stress while maintaining visual quality. In areas facing increased water scarcity, it is possible that grey water can be used for ornamental production and maintenance. The purpose of the research was to determine the viability of utilizing grey water for greenhouse production of 10 common autumn bulbs (3 daffodil, 2 tulip, 2 crocus, 1 allium, 1 iris, and 1 hyacinth cultivars). Growth, flowering time, flower duration, and nutrient analysis were utilized to determine the impact of grey water. Grey water irrigation did not significantly alter leaf length, leaf number, flower number, flower duration and leaf water status compared to the control. However shoot biomass was significantly reduced in the grey water treatment, with the greatest reduction in hyacinth (reduction of 30%). Leaf chlorophyll content was comparable between the grey water treatment and the control after 119 (28 days of treatment) of treatment, but by 140 days of treatment (49 days in the greenhouse) chlorophyll content was reduced in the grey water treatment compared to the control. Despite this decrease we did not observe a decrease in carbon assimilation, stomatal conductance and transpiration rate. Our results indicate that grey water would be a viable irrigation source for 10 fall bulb species.