Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/9/2001
Publication Date: N/A
Technical Abstract: A trial was conducted in a reniform nematode-infested cotton field with uniform sandy clay loam soil at Weslaco, Texas to examine the consequences of fumigating soil down to 92 cm in relation to reniform nematode kill, subsequent nematode population development, cotton root growth, and cotton ling yield. Deep fumigation was achieved in late November 1999 by digging post holes 90 cm deep and placing 2 ml of Telone II (1,3-dichloroprpene) at depths of 90, 60, 30 cm as each hole was refilled. Holes were dug on 51-cm centers along the top of the bed the same day that beds were formed and along the adjacent furrow 51 cm to one side, for a distance of three meters. Deep manual fumigation killed most reniform nematodes within the soil profile down to 105 cm as well as 50-100 cm laterally in all directions from the point of placement. Chisel fumigation, by comparison, killed appreciable numbers of nematodes no deeper than 60 cm. At harvest, root density was highest near the surface and more or less uniform from 30 to 105 cm deep. Fumigation did not alter root architecture appreciably. The most striking difference between fumigant treatments was continued nematode population control observed at harvest at all depths following deep fumigation, compared with complete recovery of nematode populations in chisel-fumigated plots. Fumigation doubled yields in both cases.