Label Confusion in a Greenhouse Aphid Control Decision
A grower's greenhouse contains tomatoes, cucumbers, and a block of ornamental bedding plants in adjacent benches. Aphids are found on the tomatoes and on the bedding plants. The applicator has two products on hand. Product A is labeled for aphids on greenhouse tomatoes and cucumbers, with a 12-hour restricted-entry interval (REI) and a 1-day preharvest interval (PHI); its label states 'not for use on plants grown for sale or for ornamental use.' Product B is labeled for aphids on ornamentals and greenhouse vegetables, REI 4 hours, PHI 0 days for vegetables, but its label prohibits use in greenhouses 'where bees are used for pollination.' The grower uses bumblebees in the tomato house. The applicator plans one tank mix of A plus B to treat all benches at once to save a trip.
1. Evaluate the proposed tank mix bench by bench. Which uses are permitted by the labels as described, and which are not?
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Treat each bench separately; the tank mix as proposed is not defensible.
- Tomatoes: Product B is prohibited where bees are used for pollination, and the grower uses bumblebees in the tomato house, so B cannot be used there. Product A is labeled for greenhouse tomatoes, so A alone is permitted on tomatoes under its label (REI 12 h, PHI 1 day).
- Cucumbers: Product A is labeled for greenhouse cucumbers, so A alone is permitted. B is barred by the bee restriction in that house.
- Ornamental bedding plants: Product A's label excludes plants grown for sale or ornamental use, so A cannot be used. Product B is labeled for ornamentals, but the bee prohibition applies only where bees are used for pollination; the bedding block has no bees, so B may be used there.
A tank mix of A plus B applied to all benches would put A on ornamentals (off-label) and B in the bee house (off-label). The applicator should treat tomatoes and cucumbers with A, and the bedding block with B, in separate applications with the equipment cleaned between uses per label directions.
2. The applicator argues that because the tank mix is 'one pass,' it saves time and reduces exposure. How should the supervisor respond, and what records matter?
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Time savings do not override label restrictions. Applying A to ornamentals and B in the bee house would each be a use inconsistent with the label, which is a violation regardless of intent. The supervisor should direct separate applications with correct products, observe the 12-hour REI for A in the tomato/cucumber house, keep workers out during the REI, and follow the bee-restriction by not using B in the tomato house.
Records that matter: product name and EPA registration number, rate, date/time, location (bench/house), applicator name, and REI/PHI observed. Documenting which product went to which bench demonstrates compliance and protects the grower if a residue or bee-kill complaint arises. Also record equipment cleaning between products to avoid cross-contamination of ornamentals with A.
3. What should the applicator do about the bees in the tomato house if a product labeled for the pest there had a bee caution rather than a prohibition?
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Read the exact label language. A prohibition means do not use where bees are used for pollination, full stop. A caution (e.g., 'toxic to bees; do not apply while bees are foraging') allows use if timing and conditions protect bees. In that case the applicator would remove or confine the bumblebee hives, apply when bees are not active (evening or when hives are closed), and keep them closed until the label-specified interval has passed. The applicator should not substitute a different product without confirming it is labeled for greenhouse tomatoes and compatible with the pollination program. When in doubt, contact the manufacturer or the state lead agency before applying.