Laboratory and Field Evaluations of Sorghum for Response to Aluminum and Acid Soil1

Publisher Website
Google Scholar
Abstract
Plant responses in controlled environments (greenhouse and growth chamber) should relate to field plant responses if laboratory screening methods are to be used effectively for the improvement of plant tolerances to soil stress conditions. Eight acid soil susceptible and tolerant sorghum [Sorghum bicolor (L.) Moench.] genotypes were compared for dry matter production, element uptake, and visual plant stress symptoms under field stress (Georgia) and artificially‐induced Al‐toxic nutrient solutions (Nebraska). Sorghum was grown on three soil types (Typic Rhodudults, Fragiaquic Paleudults, and Typic Hapludults) and at three levels of Al (0, 46, 93 µmol L−1) in nutrient solution. Net seminal root lengths were used to evaluate plants for Al tolerance in the laboratory. The objectives of this study were to compare sorghum genotype responses when plants were grown under both field and laboratory conditions to determine genotypic differences and to better quantify Al and acid soil tolerance screening techniques. Among the genotypes studied, SC0283 was the most tolerant to acid soil field stress conditions and was also the least affected by Al toxicity conditions in nutrient solutions. NB9040 was susceptible to acid soil field conditions, exhibited considerable tolerance to medium levels of solution Al, and was susceptible to high levels of solution Al. Tolerance or susceptibility to Al among the sorghum genotypes was influenced by the level of the acid soil stress condition. Manganese toxicity probably affected plant responses in the field. Genotype responses to Al‐induced stress conducted in the laboratory and to acid soil stress conducted in the field showed similar responses when the screening parameters for each environment were quantified. The susceptibility response of NB9040 was equivalent at 93 µmol L−1 Al (32 µmol L−1P) in solution and pH 4.4 to 4.8 for the three soils used in this study.