The effectiveness of selected nematicides for management of the Columbia lance nematode, Hoplolaimus Columbus , on cotton was evaluated in field experiments. Aldicarb at rates of 0.84 to 1.18 kg (a.i.)/ha was effective in increasing cotton lint yield in several experiments with cultivars that were moderately tolerant to this nematode, whereas fumigant nematicides were required to provide significant yield increases on intolerant cultivars. Metam sodium and 1, 3-dichloropropene (1, 3-D) were effective in limiting population densities of H. columbus at two locations at both mid-season and at cotton harvest compared to controls or to the non-fumigant nematicide aldicarb. Cotton lint yield of an intolerant cultivar was positively related to the application rate of metam sodium or 1, 3-D at one location with a high initial population density (Pi) of this nematode, but not at a second location with lower (Pi) and lower sand content. Treatment of soil with relatively high rates of fumigant may alleviate the need for treatment in the subsequent year.
