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Breeding of maize for low rainfall areas of Kenya:1. The reliability of yield of early and later maturing maizes

Published online by Cambridge University Press:  27 March 2009

B. D. Dowker
Affiliation:
Katumani Research Station, Department of Agriculture, Kenya

Summary

A trial to compare the reliability of yield of a quick maturing maize (Taboran) with the medium maturity local maize was carried out at two low rainfall sites in Southern Province, Kenya, from 1957 to 1961. Each variety was grown at two spacings, giving plant densities of 1·8 and 3·6 pl./m2. Results showed a consistent difference in ‘days to 50% silking’, Taboran being on average 17 days earlier than Local White. There was no overall difference between varieties or spacings in yield per ha. There were highly significant interactions of seasons with varieties and with spacings. These were interpreted in terms of different linear yield/rainfall relationships for each variety and each spacing. A variety/spacing interaction was also demonstrated.

Analysis of components of yield showed that similar linear relations between rainfall and each yield component obtained. There were significant differences between varieties and between spacings in both mean number of cobs per plant and yield per cob. Taboran had a higher mean number of cobs per plant and Local White a higher mean yield per cob. Seasons x varieties interactions were again interpreted in linear regression terms. Earliness of the Taboran variety often enabled plants to produce silks before development was arrested by drought and so was responsible for its relatively high mean number of cobs per plant in low rainfall seasons, giving it an advantage over Local White in yield per unit area in such circumstances. Taboran was shown to have a potential value in local agriculture, because of its consistency of yield. The expected advantage or disadvantage of Taboran over Local White was calculated for an area of known rainfall from the respective yield/rainfall regressions and the seasonal rainfall probabilities.

Selection for earliness was shown to be of basic importance in a breeding programme for the low rainfall areas. Within a specified early maturity range, selection for yield improvement through the yield per cob component could be practised. A maturity length similar to Taboran would ensure a high value of mean cobs per plant in low rainfall season, i.e. confer the necessary reliability of yield.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1971

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References

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