Vinca [Catharanthus roseus (L.) G. Don], salvia (Salvia splendens F. Sellow ex Roem. and Schult.), Dwarf Yaupon holly (Ilex vomitoria Ait. ‘Nana’), and ‘Helleri’ holly (Ilex crenata Thunb. ‘Helleri’) were grown in 2.3-L containers with soilless substrates in a greenhouse. Irrigation was applied as needed to the substrate surface or applied to the substrate surface and applied over plant foliage. Irrigation for both application methods was composed of 0%, 25%, 50%, 75%, or 100% reclaimed water (processed sewage) with deionized water composing the remainder. Shoot dry weights of marketable-sized plants were either larger or similar when 100% reclaimed water was used compared with 0% reclaimed water (deionized). Root dry weights exhibited a similar response except for salvia roots that were smaller with 100% reclaimed water irrigation regardless of application method. Leachate NO3-N, phosphorus (P), and potassium (K) generally decreased throughout the experiments for vinca and Dwarf Yaupon holly and were highest at experiment midpoint for ‘Helleri’ holly and lowest for salvia. Leachate electrical conductivities (ECs) were generally highest at experiment termination for vinca and salvia, whereas ECs of Dwarf Yaupon and ‘Helleri’ holly tended to peak at experimental midpoint and then decrease slightly at termination. ECs were usually less than 2 dS·m−1 except at experimental midpoint (4.5 months) for ‘Helleri’ holly. Based on the response of plants in this research, high-quality reclaimed water is a viable water source for annual and woody container-grown nursery crops.
Thomas H. Yeager, Joseph K. von Merveldt and Claudia A. Larsen
Roberto Testezlaf, Fedro S. Zazueta, Claudia A. Larsen and Thomas H. Yeager
The objective of these experiments was to evaluate the use of tensiometers to monitor substrate moisture tensions for Metro-Mix 500 and 2 pine bark: 1 Canadian peat: 1 sand (PBPS, by volume) used for container-grown azalea Rhododendron indicum L. `Mrs. G.G. Gerbing' and chrysanthemum (Dendranthema grandiflora Tzvelez.) `Coral Charm.' Commercially available ceramic cups of two sizes, small [0.374 inch (0.95 cm) diameter and 1.125 inches (2.86 cm) long] and large [0.874 inch (2.22 cm) diameter and 3.0 inches (7.62 cm) long] were used to construct pressure transducer-equipped tensiometers. Data from these greenhouse experiments, indicate that either the small or large ceramic cup could be used to monitor substrate tensions at which water would be available to container-grown plants.