A technique for minimising confounding of genotype x year and genotype x crop type effects in sugarcane
✍ Scribed by P. N. Jones; R. Ferraris; L. S. Chapman
- Publisher
- Springer
- Year
- 1993
- Tongue
- English
- Weight
- 457 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0014-2336
No coin nor oath required. For personal study only.
✦ Synopsis
Genotype x year (G x Y) and genotype x crop (G x C) interactions may be confounded in sugar cane when data is obtained from the plant crop and/or from ratoon crops in successive years. A technique to minimise the effects of confounding of the G x C interaction with the G x Y interaction is presented. The mean yield of cane from neighbouring farms was used as an indicator of the year (environment) effect. It was used to re-analyse yields from three experiments comparing six genotypes grown over a plant crop and three ratoons. Two experiments were grown under rainfed conditions and one experiment was irrigated. The confounded interactions were partitioned into a linear contrast on the farm yields (a year effect) and a crop effect that was the remainder. When the yields adjusted for the farm yield effects were compared with original yields of cane, yields of plant and first ratoon were reduced and those of third ratoon were increased. There were only minor changes in the ranking of genotypes on yield. It was concluded that the re-analysis using farm yield showed that the confounding effect of years on the interpretation of genotype x crop effects was small. * The plant crop of the irrigated experiment was grown as a rainfed crop, hence the value of farm yield used for this crop was 87.1, the same as for MSES rainfed.