EVALUATION OF ETHOPROP AND TETRATHIOCARBONATE FOR RENIFORM NEMATODE CONTROL IN PINEAPPLE

Ethoprop and disodium tetrathiocarbonate (TTC) were evaluated as repla cements of fenamiphos and 1,3-dichloropropene (1,3-D) for control of R otylenchulus reniformis on pineapple in Hawaii. Treatments were establ ished in a field on the Del Monte Fresh Fruit (Hawaii) plantation in s pring 1991. Preplant soil treatments consisted of fumigation with 1,3- D at 226 kg a.i./ha and TTC at 135 kg or 270 kg a.i./ha. Postplant nem aticides for the 1,3-D treated plots were fenamiphos (3.4 kg a.i./ha t rimonthly) and ethoprop (3.4 or 6.7 kg a.i./ha monthly). Tetrathiocarb onate was applied postplant to the TTC-treated plots every 2 months at 67 kg a.i./ha. Nematode population densities were monitored in all pl ots at 3-month intervals. Tetrathiocarbonate was not effective in redu cing the preplant soil population densities of R. reniformis or limiti ng subsequent nematode damage to the plants. Ethoprop and fenamiphos r educed nematode damage, resulting in greater yield in the first and se cond crop harvests (P < 0.05). Ethoprop was an effective alternative t o fenamiphos for control of R. reniformis in pineapple.