Short communications

An evaluation of two collections of South African maize (Zea mays L.) germ plasm: 2. The genetic basis of dry-down rate

Published in: South African Journal of Plant and Soil
Volume 21, issue 2, 2004 , pages: 120–122
DOI: 10.1080/02571862.2004.10635035
Author(s): B. de JagerDepartment of Genetics,, C.Z. RouxDepartment of Genetics,, H.C. Kühn,


Dry-down rate is the loss of moisture from maize kernels over time. This study was undertaken to determine whether collections of early and late flowering South African germ plasm have the same genetic properties with reference to dry-down rate as reported for foreign germ plasm. If so, a dry-down rating may be included in South African maize breeding programmes in order to select for a decreased moisture percentage at harvest. This will facilitate the production of high yielding varieties and hybrids of good quality grain that do not need to be mechanically dried, thus decreasing production costs. To achieve this Griffing's (1956a and 1956b) Model II combining ability analyses were performed on two diallels representing the early and late flowering maize cultivars, respectively. Additive genetic variance was more important in the expression of dry-down rate than dominance, as previously found in foreign germ plasm. This together with the heritabilities estimated, indicate that dry-down rate is amenable to improvement by selection in the germ plasm under investigation. It is concluded and confirmed that dry-down rate is a heritable character and that its inclusion into breeding programmes may play a role in increased profit margins to the producer.

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