The coffee tree trapezoidal design has been a serious obstacle to agrochemical use which is supposed to reach the fruits directly. Depending on the coffee variety this problem can become even greater. This experiment aimed to evaluate and compare a tracer solution distribution and deposition as well as to verify the efficacy of the ethephon growth regulator on coffee fruit ripening. Different operational conditions and sprayers were used. Water-sensitive paper and a visual grade scale used for different fluorescence levels emitted by the tracer solution have enable spraying distribution evaluation. Quantitative evaluation of tracer deposition and ethephon efficacy were carried out through spectrophotometry and relative percentage of unripe and ripe fruits, respectively. A higher deposition in lower canopy was obtained using Arbus 400 air carrier sprayer equipped with HC-02 and JA-2 hollow-cone nozzles. Better spraying distribution was observed in fruits at lower canopy and frontally toward spraying. The highest percentage was obtained using HC-02 nozzle Arbus 400 equipment under lower work pressure, although it was not enough to reduce ripe fruit to less than 20% following 59 days from ethephon application.
application technology; air carrier sprayer; ethephon; tracer; coffee tree
