Selecting for nutrient use efficiency within forage grass species: I. Development of a screening system

One means of achieving increased forage grass production on infertile soils is to select plant genotypes which grow efficiently at low levels of available nutrients. This requires methods to identify variability in individual plant nutrient response from among large populations of plants grown under controlled environmental conditions.

A compact, containerized system, partially developed for growing large numbers of forage grass seedlings for use in automatic machine transplanter research, was adapted as the basis for such a screening technique. Three trials were made with 100‐plant samples of a kleingrass‐75 (Panicum coloratum L.) population to test the utility of the system. Results of these trials showed that differences in nutrient use efficiency (= reciprocal of nutrient concentration in the plant tissue, or milligrams dry matter produced per milligram nutrient absorbed) among the grass plants could be effectively identified by using the system in conjunction with laboratory analysis of the material grown. Plants could be maintained in vigorous condition during several harvest periods, and those selections that were retained could be easily transplanted for further propagation and evaluation.