Chemical Defoliation of Fig Nursery Stock Using Ethephon, Harvade, and D-WK Surfactant
Application of harvade (2,3 Dihydro-5, 6-dimethyl-l, 4-dithiin 1,1,4 tetroxide) and ethephon (2-chloroethyl phosphonic acid) in combination with Dupont-WK (D-WK) surfactant (principle functioning agent the dodecyl ether of polyethylene glycol) resulted in significant leaf abscission of Ficus carica. Two applications at weekly intervals of 200 ppm harvade or 400–800 ppm ethephon in combination with 20% D-WK surfactant resulted in acceptable defoliation without plant injury in two tests. In one test, defoliation was achieved with lower rates of harvade or ethephon but significant plant injury occurred. Plant injury was as great with D-WK applied alone as with the addition of harvade or ethephon.
Contributor Notes
2Professor, Associate Professor, and Research Associate, Department of Horticulture, resp.