Maternal Effects Due to Organic and Conventional Growing Conditions in Spring Barley (Hordeum vulgare)

ABSTRACT

Seed quality may be especially important in organic agriculture because poor early performance is not as readily compensated for later with the aid of fertilizers and pesticides as in conventional agriculture. Environmental conditions of parent plants can influence seed and seedling performance (maternal effects). This study evaluates maternal effects on yield and germination in spring barley. A field experiment with four varieties of spring barley was carried out over 4 years in organic and conventional experimental systems. Every year, seeds from varieties previously grown in the organic system were sown in the organic system and the conventional system; seeds from varieties previously grown in the conventional system were sown in the conventional system and the organic system. Grain yield, proportion of seeds above 2.8 mm in harvest samples, field germination percentage, field mean germination time, laboratory germination and seed protein content was analysed. Results showed that seeds of organic origin performed poorer than conventional counterparts with respect to yield and mean germination time, whereas samples from the organic system generally had a larger proportion of large seeds. Seed protein content was lower in samples from the organic system, but no correlations between protein content and field germination properties were observed. In the laboratory germination test there was a negative correlation between mean germination time and protein content. It is concluded that organic seed production should focus on other management efforts in order to compensate for the poorer germination and yield performance in seeds of organic origin.