Developing a Breeding Strategy for Improved Performance in Programmed Cropping Systems

Fifty-one lines from the EMR breeding programme were compared in a 60-day field trial. There were significant differences between genotypes for mean crown diameter, number of inflorescences, flowers per plant and marketable yield (grams per plant). However there was no significant correlation between crown diameter and yield, despite it being known there is a strong relationship between crown diameter and yield with 'Elsanta'. However, there was a strong positive correlation between yield and number of inflorescences per plant, indicating the propensity to initiate more than one inflorescence per crown is independent of crown diameter. A further experiment was performed to investigate the inheritance of traits related to 60-day performance. Five lines that performed well in the first 60-day field trial were inter-crossed and progeny raised to establish a second 60-day field trial. There were significant differences between lines, and the genetic variation for inflorescences per plant and yield was found to be predominently additive. The parental lines divided into two groups, with one group passing a significantly greater number of inflorescences to their progeny than the other. The results of these trials suggest that the number of inflorescence per plant is a key trait, and the strongly additive inheritance suggests that selecting parents on phenotype will be an effective strategy for breeding for improved programmed cropping performance.