Nitrogen harvest index as a selection criterion in oats

Abstract

A population of 480 random lines of oats (Avena sativa L.) were grown on soil that received no application of nitrogen (N) or 112 leg of N ha ^ (defined as low and high N environments, respectively) to evalu­ ate the effect of N availability in the soil upon the plant's ability to partition N between vegetative tissue and the grain, a ratio defined as nitrogen harvest index (NHI). Comparisons were made between low and high N environments for grain yield (GY), straw yield (SY), biological yield (BY), groat protein yield (GTPY), groat protein percentage (GTPP), vegetative protein yield (VPY), straw protein percentage (SPP), total plant protein yield (TPPY), and harvest index (HI). Genotype x N level interaction was not significant for NHI. The high N environment caused significant increases in TPPY, VPY, and SPP, and significant reductions in NHI and HI. GY, SY, BY, GTPY, and GTPP were not different in the low and high N environments. NHI and TPPY were negatively correlated in the low N environment but independent in the high N environment. NHI was positively correlated with GY and GTPY in both environments, and positively correlated with GTPP only in the high N environment.