1. OBSERVATIONS OF TREE DAMAGE AFTER HURRICANE WILMA FROM BOTH HAND AND MECHANICALLY HARVESTED TREES Kelly Morgan, Mongi Zekri, Fritz Roka & Bob Rouse

2. Does mechanical harvesting make citrus trees more prone to hurricane damage?  Assumptions  Trunk shaker may cause more root damage  Valencia more prone because last harvested prior to hurricane  Long term shaking may lead to greater hurricane damage

3. Survey  Harvesting History Only hand harvested ≤ Short term mechanical harvesting ( ≤ 2 yrs) Long term mechanical harvesting ( ≥ 4 yrs)  Blocks Valencia only 2 groves 9 blocks 551 acres  Damage levels Canopy loss greater than 25% (no trunk movement) Trunk leaning Tree blown over and reset (top buck-horned)

4. Pruned Tree

5. Leaning Tree

6. Toppled Tree

7. Results - Block Trees per Acre Percent Tree Spaces Harvesting Method AcresPrunedLeaningToppledTotalPrunedLeaningToppledTotal Hand 2520.280.811.23 2.310.180.530.81 1.52 Short Term 1480.740.843.17 4.750.490.502.23 3.22 Long Term 1510.400.312.22 2.250.220.201.37 1.27

8. Hurricane Winds Source: SWFREC FAWN station

9. Wind Direction North East Source: SWFREC FAWN station

10. Edge Effect

11. Effects of Open Areas Ditches Ponds Toppled Leaning Pruned

12. Results – Exposed Areas Trees per Acre Percent Tree Spaces Harvesting Method AcresPrunedLeaningToppledTotalPrunedLeaningToppledTotal Hand 15.60.322.333.66 6.310.101.311.91 3.32 Short Term 8.10.271.634.75 6.650.161.422.81 4.39 Long Term 9.10.372.259.52 12.140.211.255.29 6.75

13. Conclusions  Hurricane damage in mechanical harvested blocks was not significantly more severe than damage in hand harvested blocks.  The exposed tree rows had about 3 times the amount of damage, but their damage was not significantly different from damage to trees in the rest of the block.