Individual Protective Covers
Posted August 2025
Researchers: Fernando Alferez, Ute Albrecht, Ozgur Batuman, Jawwad Qureshi, Saoussen Ben Abdallah
Contact: Fernando Alferez, UF/IFAS SWFREC alferez@ufl.edu
Summary:
Individual protective covers (IPCs) are a strategy based on psyllid exclusion of individual trees using a protective mesh bag. IPCs can be installed on solid blocks of trees or in resets. IPCs are especially valuable for planting reset trees in gaps left by dead or removed trees in mature groves where huanglongbing (HLB) incidence is typically higher and the risk of infection is therefore greatest. IPCs should be placed immediately during planting to prevent any exposure of trees to the psyllids. In our research, we have found that IPCs effectively exclude psyllids, maintain trees free from HLB, and reduce canker incidence. We also found IPCs do not exclude all pests, and armyworms, black scale, mealybug, and mites are often present. This means that regular scouting and insecticide application may still be necessary. Fruit from sweet orange varieties produced under IPCs have better internal quality and significantly more soluble solids (°Brix) than fruit from HLB-affected trees. Fruit quality is maintained at least for 2 years after IPC removal, even though trees become HLB-positive. We have tested the growth and physiology of different citrus varieties under IPCs. Our results show that sweet orange varieties (i.e, ‘Hamlin’ and ‘Valencia’), and some mandarins like ‘W. Murcott’ and ‘Tango’, as well as grapefruit, grow well under IPCs up to 3 years. Others like ‘Early Pride’ do not. Sugar Belle® mandarins grow well only for one year, with no additional benefit if IPCs are maintained for longer.
Take Home Message:
- IPCs exclude psyllids effectively in all citrus varieties tested, but other pests need regular monitoring and treatment.
- Fruit quality is greatly improved by IPCs.
- Not all citrus varieties respond equally to the IPCs.
