Fitting Plants Nutritionally to Soils. III. Sorghum1

Abstract Fifteen sorghum (Sorghum bicolor (L.) Moench) lines, representing diverse germplasm currently used in crop breeding programs in the United States, were grown on the seven soils, used in part I of this study, to produce Fe, Zn, and Cu stresses or Al and Mn toxicities in soybeans. All 15 sorghum lines developed Fe and Zn deficiencies with symptoms ranging from some interveinal chlorosis to necrotic and twisted leaf tips. The sorghum lines responded differentially to Cu stress. When Cu was added to the soil, yields increased and P, Fe, and Zn concentrations significantly decreased in the plant material. The sorghum lines responded differentially to Al in Bladen soil. Five lines grew poorly and developed a chlorosis with some purple pigmentation; five lines were green and made good growth; and five lines were intermediate in their response. The chlorotic lines contained significantly less Fe and P than the green sorghum. On Richland soil (high Mn), yields were relatively good and the sorghum plants did not develop any persistent toxicity symptoms. Care should be taken to select the sorghum line best adapted to Fe, Zn, or Cu stresses and to Al toxicity so that the plant and the soil may be compatible.