2017 ASHS Annual Conference
Growth of ‘Looking Glass’ Begonias Using Saline Irrigation Water from Various Sources
Growth of ‘Looking Glass’ Begonias Using Saline Irrigation Water from Various Sources
Wednesday, September 20, 2017: 10:30 AM
Kohala 4 (Hilton Waikoloa Village)
Water shortages and saltwater intrusion are becoming increasingly prevalent problems for the ornamental horticulture industry. In the near future, some nurseries may need to learn how to best grow crops with lower quality saline irrigation water, including water from alternative sources such as treated reclaimed wastewater. Two experiments were conducted in order to compare the growth and quality of salt-sensitive begonias (Begonia x ‘Looking Glass’) when produced in a greenhouse setting using saline irrigation water from various sources and at different volumes. All plants were grown in soilless media with a low rate of incorporated controlled release fertilizer in trade gallon pots for a period of six weeks. Plants in the first experiment were irrigated three times per week with 250 mL of full- and half-strength solutions of either deionized water, liquid fertilizer, saline water, or wastewater. In the second experiment, plants were irrigated exclusively with the full-strength solutions from the same four sources. However, in this iteration the irrigation volumes varied from 100 to 350 mL. Saline water and liquid fertilizer lead to higher rates of mortality and stunting. Shoot dry weights were greatest in plants receiving the liquid fertilizer, comparable in plants irrigated with the deionized water and wastewater, and lowest in plants receiving saline water. In general, plants that received 250 mL at each irrigation yielded the greatest shoot dry weights compared to plants receiving either 100 or 350 mL. Leachate EC’s and Na levels were highest in the plants irrigated with full-strength liquid fertilizer and saline solutions. Levels of K were highest in plants irrigated with the liquid fertilizer and relatively low in all other treatments. The ratio of Na to K in the irrigation water was a better indicator of shoot growth than the total level of salinity alone.