Harvesting Methods Effect on Citrus Water Dynamics.

Changes in grove management practices may change crops water dynamics.  The objective of this study was to estimate sap flow and stem water potential (Ψ_stem) as affected by harvesting methods. The study was initiated in March, 2016 on five-year-old commercial sweet orange (Citrus x sinensis (L.) Osbeck) grove located at Felda, Florida (26.61° N, 81.48° W) on felda fine sand soil (Loamy, siliceous, superactive, hyperthermic Arenic Endoaqualfs). Sap flow measurements were taken for four trees instrumented with two sensors per tree. Sap flow was measured by the heat balance method at hourly intervals from March, 16 to April, 13 and from April, 13 to 27. Also, the Ψ_stem was measured before and after harvest using a Portable Plant Water Status Console. Results indicated significant (α=0.05) changes in Ψ_stem between hand and mechanical harvesting methods after harvest. The average value of Ψ_stem measured increased by 4% under mechanical harvesting and declined by 8% under hand harvesting. Indicating trees stress increase under mechanical methods. Also, the sap flow (g hr^-1) significantly increased by 14% and 19% after mechanical and hand harvesting, respectively. This study concludes that the hand harvesting method is less stressful and less impactful on tree water uptake compared with mechanical harvesting.