CONTROL OF ROTYLENCHULUS-RENIFORMIS ON PINEAPPLE WITH EMULSIFIABLE 1,3-DICHLOROPROPENE

An emulsifiable formulation of 1,3-dichloropropene (1,3-D SL) was test ed for efficacy against Rotylenchulus reniformis, the reniform nematod e, in pots and in the field. Nematode population densities were reduce d by 50% at 25 mu g a.i. per g of soil in pot trials. In the field, ef ficacy (posttreatment numbers divided by pretreatment numbers) was sim ilar between 1,3-D SL and 1,3-D VL (volatile liquid) at 407 kg a.i./ha . At 204 kg a.i./ha, 1,3-D SL was less effective than 1,3-D SL or VL a t 407 kg a.i./ha in controlling the nematode but gave better control t han no treatment (P < 0.05). Postplant application of 113 kg a.i. 1,3- D SL per ha did not provide sufficient nematode control to prevent yie ld reduction compared with a postplant fenamiphos (1.7 kg a.i./ha) tre atment. Preplant fumigation with 1,3-D reduced the numbers of reniform nematode, but the population resurged within 10 months. Thereafter, r egardless of nematicide, soil population densities of R. reniformis di d not differ among treatments.