Growth Response of Peanut to Field Inoculation with Endomycorrhizal Fungi, Bradyrhizobium, and Supplemental Phosphorus in Texas1

Abstract

Abstract Field studies were conducted at four locations in Texas over a two year period to assess the response of five peanut cultivars to inoculation with four species of vesicular-arbuscular endomycorrhizal fungi (VAMF) with or without Bradyrhizobium sp., and Bradyrhizobium alone. Supplemental phosphorus treatments were also included. Replicated treatments were superimposed upon indigenous microflora in five nonfumigated field plots. Soil phosphorus (up to 50 ppm) did not necessarily stimulate peanut growth nor negate growth stimulation by mycorrhizal fungi. VAMF species differed in their effectiveness for increasing peanut growth characteristics such as root, shoot, and pod weights but did not affect peanut yield. Cultivars also responded differently to inoculation. Shoot and root weights of inoculated plants increased more rapidly than the controls early in the growing season. Increased dry pod weights were obtained at two locations; however, yields of peanut from all treatments at harvest were statistically similar. The value of fieldinoculation of peanut with vesicular-arbuscular endomycorrhizal fungi used in this research is discussed.