Abstract:

Acid infertile tropical soils are a major constraint on production in much of the tropics. attributes the objectives of this study were to identify of acid soil tolerance and study their inheritance. Thirty-four genotypes consisting of 10 parents and 24 Fx Carolina Mating Design II were hybrids from a North evaluated in Mississippi and at four acid soil locations in Kenya in 1990 and 1991. There were significant differences flower, plant height, head length, among genotypes for days to peduncle length, number of grains per head, grain yield, and 1000 years; however, seed differences among were generally confined to the weight at most of locations in both parents and expressions of heterosis better environments, Mississippi State University and Obambo. Agronomic traits which appeared to be good indicators of tolerance to acid soil conditions included earlier maturity, taller plants, ability was longer heads, and higher yields. General combining the primary source of genetic variation for these traits and, consequently, should respond rapidly to selection and could be utilized in either a cultivar or an Fx hybrid. Soil acid had characters; however, an adverse effect on several superior hybrids most were agronomic identified acid soil environments. Tolerant males, in IS7254C and IA28, consistently imparted good agronomic characteristics to conditions, while TX623 and Wheatland their hybrids under low pH were combiners. There were the best female general significant differences among genotypes for most mineral element concentrations . leaf Elements which showed the most promise as indicators of tolerance to acid soil were calcium and magnesium; however, measurements of leaf mineral element concentrations are expensive, time consuming, and require highly skilled labor. Consequently, agronomic traits would be more efficient evaluators of acid soil tolerance, particularly in developing countries, where much of the world's acid soils are found. Broad-sense and narrow-sense heritabilities for most traits tended to be higher in the better environments. Heritabilities for days to flower, plant height, and peduncle length were generally high, but other agronomic characteristics were typically in the low to intermediate range and showed considerable variation across locations. Heritabilities for mineral element concentrations tended to be low to intermediate.