When using an air-carrier sprayer, what proportion of the spray should be applied to the top half of the tree?

When using an air-carrier sprayer, what proportion of the spray should be applied to the top half of the tree?

• A. One-half
• B. Two-thirds
• C. Three-quarters
• D. All of It

Answer: (B)

The key idea is to place most of the spray where the leaf surface is most accessible and where pests are most likely to be found—the upper portion of the canopy. Spraying the top two-thirds of the tree ensures the majority of the foliar area gets direct contact with the spray, which improves coverage and pest contact without over-wetting the lower parts or the ground. Droplets that aren’t needed in the lower third are less efficiently deposited there, and spraying too little (one-half) risks missing upper leaves, while spraying more (three-quarters or all) wastes product and can increase drift or runoff. So targeting the top two-thirds gives effective canopy coverage with efficient use of the spray.

The key idea is to place most of the spray where the leaf surface is most accessible and where pests are most likely to be found—the upper portion of the canopy. Spraying the top two-thirds of the tree ensures the majority of the foliar area gets direct contact with the spray, which improves coverage and pest contact without over-wetting the lower parts or the ground. Droplets that aren’t needed in the lower third are less efficiently deposited there, and spraying too little (one-half) risks missing upper leaves, while spraying more (three-quarters or all) wastes product and can increase drift or runoff. So targeting the top two-thirds gives effective canopy coverage with efficient use of the spray.