Why should you have one sprayer for herbicides and another for insecticides and/or fungicides?

Why should you have one sprayer for herbicides and another for insecticides and/or fungicides?

• A. It saves time
• B. Herbicide residues may remain in the sprayer and injure sensitive plants
• C. It is required by regulations
• D. It prevents rust

Answer: (B)

Cross-contamination is the main issue. Herbicides can leave residue in the tank, hoses, seals, and nozzle tips that isn’t completely removed by a simple rinse. If that residue is later sprayed onto plants you’re protecting with insecticides or fungicides, it can injure sensitive ornamentals or crops. Some herbicides are particularly persistent or chemically different from other pesticides, so even small amounts carried over can cause phytotoxicity or unpredictable effects. Dedicating a sprayer for herbicides eliminates the risk of those residues contacting plants treated with other pesticides, which is why it’s the preferred practice.

Cross-contamination is the main issue. Herbicides can leave residue in the tank, hoses, seals, and nozzle tips that isn’t completely removed by a simple rinse. If that residue is later sprayed onto plants you’re protecting with insecticides or fungicides, it can injure sensitive ornamentals or crops. Some herbicides are particularly persistent or chemically different from other pesticides, so even small amounts carried over can cause phytotoxicity or unpredictable effects. Dedicating a sprayer for herbicides eliminates the risk of those residues contacting plants treated with other pesticides, which is why it’s the preferred practice.