2017 ASHS Annual Conference

Improved knowledge of citrus water use and soil moisture distribution in Huanglongbing (HLB) (Candidatus Liberibacter asiaticus, CLas) affected groves is critical for devising appropriate recommendations for optimizing water use and sustaining citrus yields. Two studies were conducted 1) to investigate soil moisture movement and water use patterns in HLB affected groves in central, south-central and southwest Florida using 1) daily irrigation (Daily), 2) Institute of Food and Agricultural Sciences (IFAS) recommended scheduling, and 3) irrigation scheduled half the number of days between irrigation recommended by IFAS (Intermediate); and 2) determine water use patterns of Hamlin and Valencia orange trees infected with CLas. In the field study, water use pattern was largely of the order Daily>IFAS>Intermediate. Moisture contents were similar among irrigation schedules varying between 5 to 20%, 1 to 14% and 5 to 25% at 15-, 30-, and 45-cm soil depths, respectively, increasing with depth. The greenhouse study of HLB affected and non-affected trees showed a significant reduction in water use by citrus trees affected by HLB. These findings should help in refining limits for available water contents and estimating irrigation water demand to sustain citrus productivity of HLB infected trees.