Augmentation and aldicarb treatment of nematodes in selected sugarcane weed habitats

In a single experiment, field-grown Louisiana sugarcane was augmented with phytoparasitic nematodes, treated with aldicarb, or left untreated in both weedy and weed-free habitats to study interactions among nematodes, weeds, sugarcane, and sugarcane free amino acid titers. Aldicarb reduced three of the six phytoparasitic nematode genera at various times during the two growing seasons and was associated with 17% more free proline in the sugarcane. Nematode augmentation resulted in higher field populations of Meloidogyne spp. Free cysteine, histidine, proline, and serine concentrations in sugarcane were lower where nematodes were added. Densities of Tylenchorhynchus annulatus and total phytoparasitic nematodes were lower in weedy habitats compared to weed-free conditions. Sixteen of the 17 sugarcane free amino acids were significantly lower in weed-free areas. It is suggested that further research be conducted on the relationship of plant stresses to free amino acid levels to better understand plant-mediated interactions among crop pests.