RATES AND APPLICATION TIMING OF 1,3-DICHLOROPROPENE FOR THE MANAGEMENT OF MELOIDOGYNE INCOGNITA AND ROTYLENCHULUS RENIFORMIS ON COTTON

Resumen

Replicated fumigation field trials were conducted at separate sites in Florida. One site was naturally infested with Meloidogyne incognita and the other with Rotylenchulus reniformis . The fumigant, 1,3- dichloropropene (1,3-D), was applied at rates of 16, 32, and 48 kg a.i./ha at 92, 63, 36, and 2 days before planting (DBP) Delta Pine 458BR cotton at the M . incognita site and at 69, 37, 12, and 0 DBP at the R. reniformis site. All treatments were replicated six times. Yields in the non-treated controls at the M . incognita site averaged 349 kg/ha of cotton lint whereas those across rates and timing in the 1,3-D treatments averaged 504 kg/ha. All 1,3-D treatments significantly reduced post-harvest numbers of M. incognita (12 J2/100 cm 3 soil across rates and timing) compared with the non-treated controls (460 J2). At the R. reniformis site, the non-treated controls averaged 353 kg lint/ha while 1,3-D treatment across rates and timing averaged 450 kg/ha. Post-harvest R. reniformis soil population densities of all nematode stages were not influenced by treatment (3048/100 cm 3 soil from non-treated and 3040 in the 1,3-D treatments across rates and timing). Since there were no significant negative effects from timing of application, these studies indicate that profitable applications of 1,3-D may be accomplished earlier and later than the current application recommendation of 10-21 days before planting.