based on estimates of HV dilute spraying requirements for
trees in the full-leaf stage of canopy development. In
addition, most labels state application rates on an amount
per acre basis. On smaller trees this can result in a dosage
rate several times greater than actually necessary for
control.
Research trials using airblast sprayers to apply LV
treatments in mature orchards with a spray volume
adequate for coverage, clearly demonstrate that
concentrating pesticides more than three to four times the
normal dilute concentration (pounds of the product per
100 gallons), offers no significant improvement in the
control of major tree fruit pests. This rule applies to all
fungicides, insecticides, and miticides commonly used in
commercial tree fruit production.

Going From Conventional Recommendations

To TRV

HV Sprays.Mix the pesticide at the concentration
per 100 gal recommended in this guide, and apply in
sufficient water to achieve a drip point. Total spray
volume per acre should be calibrated based on 0.7 gallons
per 1,000 cubic feet of TRV on trees with sufficient
foliage, or 0.25 to 0.35 gallons per 1,000 cubic feet of
TRV on trees with little or no foliage.

LV Sprays. Most conventional spray
recommendations state that the rate should be applied on
an amount per acre basis, and have been calculated based
on the maximum dilute spray volume required for large
trees at full leaf. Traditional LV spray recommendations
require the same amount of chemical be applied per acre
regardless of the spray volume. This means the spray
volume per acre and concentration per 100 gallons for LV
spraying must be adjusted proportionately, relative to HV
spraying requirements. Thus, if the volume used for an
LV spray is one half, one third, or one sixth that of the
estimated dilute requirement of 300 gallons per acre, that
is 150, 100, or 50 gallons per acre respectively, then the
pesticide is concentrated at 2, 3, or 6 times the usual
dilute rate per 100 gallons.
By comparison, the defined dosage approach for LV
sprays using TRV calibration calls for pesticides to be
mixed at only three to four times the normal dilute
concentration per 100 gallons and then applying a defined
LV gallonage per acre that is adequate for coverage (for
example, 0.09 gallon per 1,000 cubic feet TRV). Thus,
this approach is similar to dilute spraying, in that a fixed
concentration of pesticide is prepared and the spray
volume used varies with coverage requirements.

1998 New Jersey Commercial Tree Fruit Production Guide

27