Field Evaluation of Seedling Root Length Selection in Oats¹

Selections for long and short root length were made on 10‐day‐old oat, Avena sativa L., seedlings from two F 2 populations grown in distilled water or in a modified half‐strength Hoagland's solution. F 2 derived F 3 and F 4 progeny were grown in the field in a nonstress environment with a shallow ( 10 to 30 cm) loamy sand or sandy loam A horizon and in a stress environment with a deep (75 to 90 cm) loamy sand A horizon. Seedling root measurements were made on F 4 and F 5 plants. Root length differences were observed two and three generations after selection following growth in a modified half‐strength Hoagland's solution but differences between long and short root length selections were not consistently maintained for the selections made after growth in distilled water. Trends toward greater grain yield, seed number, and plant height were observed for the long root length selection, especially in the nonstress environment. The technique was not successful in identifying plants with superior performance in a deep sandy soil.