Development and production of iceberg lettuce irrigated with magnetically treated water

Irrigated agriculture has become a concern, given the scarcity of freshwater. To reduce its water consumption, new techniques and technologies have been proposed. Based on this, the objective of this work was to evaluate the influence of diferent soil water tensions at initiation of irrigation with magnetically treated water, on 'iceberg' lettuce Lucy Brown (Lactuca Sativa L.) development and production. The experiment was conducted in a greenhouse, using a completely randomized factorial design, to evaluate two water types (magnetically treated water - MW and ordinary water - OW) and four soil water tensions at initiation of irrigation (T1 - 15 kPa, T2 - 25 kPa, T3 - 40 kPa and T4 - 70 kPa), with three replicates. Tensiometers were used to estimate soil water tension. The evaluated parameters were: aerial part fresh and dry total mass; commercial head fresh and dry mass, root fresh and dry mass; stem fresh and dry mass; stem length and diameter; percentage of leaves with tip burn, total and commercial yield; water use eficiency related to total and commercial yield; plant exposed area; and dry matter content. Despite achieving greater water use eficiency, the magnetic treatment may have hindered the removal of water from the soil by the crop, especially at increased soil water tension at initiation of irrigation.