Assess and monitor incidences and distribution of citrus disease that pose a great risk to the industry

The Department of Agriculture Animal and Plant Health Inspection Service (APHIS) awarded a cooperative agreement to Texas A&M Agrilife Extension Service for $127,189 on September 1, 2026, to assess and monitor incidences and distribution of citrus diseases in Southeast Texas.

The work comprises two primary activities. First, field sampling will collect suspect tissues from symptomatic citrus plants, including collection of psyllids when detected and visual inspection and sampling of leaf and fruit tissues suspected of citrus yellow vein clearing virus, citrus chlorotic dwarf virus, black spot, and sweet orange scab, following APHIS/PPQ protocols. Samples will also be drawn from counties in the immediate vicinities of Harris, Fort Bend, and Brazoria counties where quarantines are in place for greening, canker, or both. Second, positive samples collected in the field will be submitted to the Texas Plant Disease Diagnostic Laboratory (TPDDL) for laboratory diagnostics, with confirmation forwarded to additional USDA laboratories. The survey will draw from hundreds of sampling sites throughout the region previously identified by Texas A&M Citrus Center in Kingsville.

Expected outcomes include early detection of citrus greening and citrus canker where present in Southeast Texas, reduced uncertainty regarding these and four additional diseases, and position Texas as a comprehensive monitoring point between California and Florida citrus production areas.

Period of performance runs from September 1, 2026, through August 31, 2027. Work is performed in Texas.

Texas A&M Agrilife Extension Service is a child entity of The Texas A&M University System.

Purpose

The purpose of this agreement is to assess and monitor incidences and distribution of citrus disease that pose a great risk to the industry.

Activities

The first is the collection of citrus greening and citrus canker suspect tissues from symptomatic citrus, sampling will also involve the collection of psyllids when detected and visual inspection and sampling of leaf and fruit tissues suspected of citrus yellow vein clearing virus, citrus cholortic dwarf virus, black spot or sweet orange scrab, following aphis/PPQ protocols. These samples will then be returned to the texas plant disease diagnostic laboratory (TPDDL) for the second activity, laboratory diagnostics. Positive samples will be then forwarded to additional USDA labs for confirmation. These survey efforts were originally intended to reflect previous surveys conducted by the texas a & M citrus center in kingsville, texas, in sampling intensity and processing. Hundreds of sampling sites throughout the region have now been identified and are available for monitoring. Counties in the immediate vicinities of harris, fort bend, and brazoria counties where quarantines are in place for greening, canker, or both will be targeted. Deliverables and expected outcomes: first, early detection of these diseases will occur where they are present in southeast texas. Second, the uncertainties concerning greening and canker will be reduced and joined with the additional four diseases, will allow the citrus industry to plan for future contingencies. Finally, texas, as mid-point state, between the production areas of california and florida will be playing a comprehensive, active role in monitoring these serious agricultural threats to the benefit of all other citrus-producing states. Intended beneficiary(IES): the entire nursey, fruit, and juice industry in texas and all the food chain that benefits from said industry to include the domestic retail, export and trade market. Aphis will benefit from early detection to increase the effectiveness of possible responses. Subrecipient activities, if known or specified at the time of award: N/a. Full agreement amount: $127,189.