Control of Hoplolaimus columbus on Late-planted Soybean with Aldicarb.

Efficacy of three rates of aldicarb for control of Hoplolaimus columbus was evaluated on highly tolerant ('Foster'), moderately tolerant ('Coker 368'), and highly susceptible ('Braxton') soybean cultivars planted on 28 June 1985. Average yields of the nontreated cultivars were 557 kg/ha for Braxton, 1,309 kg/ha for Coker 368, and 1,682 kg/ha for Foster. Yield differences were significant. Aldicarb increased yields of all three cultivars, with the most tolerant cultivar responding to all aldicarb rates and the most susceptible cultivar responding only to the low rate of aldicarb; there was no significant response to the higher rates. H. columbus population densities in the soil 6 weeks after planting were not affected by either aldicarb treatment or cultivar, whereas the populations from roots were reduced in all cultivars by aldicarb. No relationship between tolerant soybean cultivars and population densities of H. columbus was observed.