Management of Root-knot and Reniform Nematodes in Ultra-Narrow Row Cotton with 1,3-Dichloropropene.

Ultra-narrow row cotton studies were conducted during 1999 at two field sites in northern Florida. One site was naturally infested with Meloidogyne incognita Race 3 and the other with Rotylenchulus reniformis. The fumigant 1,3-dichloropropene (1,3-D) was applied broadcast at rates of 0, 16, 32, 48, 64, 80, and 96 kg ai./ha in replicated plots before planting Delta Pine 655 BRR cotton in 25-cm-wide rows. Post-harvest soil population densities at the root-knot nematode site had a significant (P </= 0.01) negative linear relationship to 1,3-D dosage level. Cotton lint yields at this site had a significant (P </= 0.01) positive linear relationship to 1,3-D dosage level. At the reniform nematode site, there was no relationship between post-harvest soil population densities of reniform nematodes and 1,3-D dosage level. However, significant (P </= 0.01) positive curvilinear relationships were found between both plant heights and lint yield to 1,3-D dosage levels.