Yeld stagnation has been a concern of cotton producers in recent years. There are many reasons which may contribute to yield stagnation including the loss of breeding time caused by transgenic cotton varieties and the diminished root health because cotton is susceptible to soilborne fungi like Rhizoctonia solani, Pythium spp., and Thielaviopsis basicola. The interaction between T. basicola and the root-knot nematode is a common phenomena in sandy soils of the High Plains of Texas. This interaction causes a substantial reduction in lateral root length and health in approximately 30 % of the irrigated fields (600,000 acres) in this region. In years when spring rains are plentiful, tap roots may fail to develop properly. In some cases, this is due to R. solani or Pythium spp. rotting the tap root off, so that the plant is totally dependent on the lateral roots for anchoring, water, and nutrient uptake. Cotton plants transformed with a chitinase (ch5) or β-1,3 glucanase (bg2) gene were subjected to severe stress by these fungi. While these genes provided a slight improvement in plant stand compared with the nontransformed parent, the transformed plants appeared to be much more robust and increased yields by as much as 74 % over the nontransformed parent (754 versus 434 lbs of lint/a). Improved root health by transgenic or traditional breeding efforts may allow cotton varieties to reach their yield potentials.