Telone – Nitrogen Interaction In The Presence Of Cotton Nematodes

Over the last 10 years, the use of soil fumigation for nematode management in cotton has become increasingly popular. While soil fumigation is relatively expensive, lint yields have consistently been improved sufficiently to make this treatment profitable in fields with severe nematode pressure. Growers in this area have observed changes in cotton growth patterns, including an increased need for growth regulators, when severely infested fields are fumigated, especially where the nitrogen fertilization had historically been higher than standard recommendations.
In 2007, a study was initiated in a commercial field near Portland, AR with a history of high nematode pressure. Twelve row strips that had received Telone II (1,2 dichloropropene) at 3 gal/a were alternated with equivalent sized strips that received no fumigation. Within each strip, five nitrogen rates (30, 90, 110, 130, and 200 lbs/a) were applied in 100 ft long plots that were randomly assigned in four replications. Data collected in 2007 included pre-fertilizer application and post-harvest soil samples for nutrient analysis and nematode population density measurement, subsoil nitrate samples, full-season weekly Cotman data collection, end of season box mapping, root gall ratings, and lint yields.
In 2008, the study was repeated on a different field on the same farm. Preliminary evaluation of the data indicate that nematode control may change the level of nitrogen fertilization that is required for optimum yields. Effects of nematode control on plant growth, development, and yield will be discussed.