Response of `Lisbon' Lemons to Irrigation Frequency in the Arizona Desert

Abstract

The majority of citrus planted in southwestern Arizona are lemons. Lemons are generally more vigorous and usually produce higher yields than other citrus cultivars. However, under water stress, fruit size will be compromised and excessive fruit drop will occur. Limited information is available that addresses the issue of irrigation frequencies and the impact on fruit sizing of lemons. A field study was initiated in 1993 evaluate the response of `'Lisbon' lemons to various flood irrigation intervals. Irrigation intervals were based on soil moisture depletion (SMD), as calculated from frequent neutron probe soil moisture measurements. Individual treatments were irrigated when total SMD was 25%, 40%, 55%, and 70%, respectively. The experiment is a completely random design with four replications. Results indicate that both the most-frequent (25% SMD) and least-frequent (70% SMD) irrigation regimes produced negative results. Overall, the first year's results indicate optimal fruit growth and yield is achieved at 40% SMD.