Growth and nutrition of guayule (Parthenium argentatum) in a saline soil as influenced by vesicular-arbuscular mycorrhiza and phosphorus fertilization.

Growth of guayule (Parthenium argentatum A. Gray) in a moderate and a highly saline-sodie soil was increased by inoculation with Glomus intraradices Schenck & Smith. The growth of guayule plants was stimulated equally by the addition to the soil of either 100 μg g of phosphorus (P) or inoculum of G. intraradices. Mycorrhizal plants had increased concentrations of PO and decreased concentrations of Na in shoot tissues compared to non inoculated control plants. Addition of 100/μgg of P to the soil increased the accumulation of PO in the shoot tissues and in most instances decrease accumulation of Cu, Zn, Na, K, and SO . Concentrations of Na, K, and Cl and frequently Mn in the shoot tissues were increased while the concentrations of PO and SO in shoot tissues were generally decreased by the addition of NaCl to the soil. Addition of 100μgg of P to the soil did not markedly affect the colonization of guayule roots by G. intraradices. The roots of mycorrhizal guayule grown in soil with NaCl added contained decreased numbers of arbuscules and vesicles. Addition of both P and NaCl to the soil reduced the formation of arbuscules and vesicles and reduced the occurrence of moderate and heavy levels of root colonization.