Abstract

Water management should be the foundation of container nursery production as it is linked directly to both water use and nutrient uptake efficiency and ultimately, environmental impact. In this study a gravimetric water management technique was used by means of a load cell/computer interface to determine irrigation volume and time of application. Cotoneaster dammeri ‘Skogholm’ was grown in 14 liter (#5) containers with an 8: 1 pine bark: sand mixture. The treatments were: an industry control that was irrigated cyclically at 1200, 1500, and 1800 HR to maintain a 0.2 LF (PM 0.2 LF); and a gravimetric treatment that irrigated when container capacity (CC) dropped below 94% and returned the CC to 98% with percentages lowered over the course of the season, always in a 4% spread, to maintain < 0.15 LF (On Demand). The number of irrigation cycles were similar until the end of the study when On Demand cycled up to seven times a day. PM 0.2 LF had a greater WUE_p (gram of dry weight produced per mL of water retained in the substrate). Time averaged application rate for On Demand was always lower than PM 0.2 LF resulting in a LF of 0.06 compared to 0.14 LF for PM 0.2 LF.