Table 3.
Deconstruction of genotype-by-year interactions including effects of experimental terms on root angle (RA), nodal root number (NRN) and seminal root number (SRN) among 20 wheat varieties at two tillage levels at the Sonning site analysed separately for the two trial years. Effect values for size of each term include F-statistic for RA and SRN and Wald statistic/d.f. for NRN. Asterisks indicate significance level: *** = p < 0.001, ** = p < 0.01, * = p < 0.05 and ‘ns’ indicates non-significance. d.f. = degrees of freedom
| Trait | Term | d.f. | Year 1 | Year 2 |
|---|---|---|---|---|
| RA | ||||
| Tillage | 1 | ns | 5.03* | |
| Genotype | 19 | 3.36*** | ns | |
| Tillage x Genotype | 19 | 2.05** | ns | |
| NRN | ||||
| Tillage | 1 | ns | 6.4* | |
| Genotype | 19 | 3.46*** | 6.77*** | |
| Tillage x Genotype | 19 | ns | 2.95*** | |
| SRN | ||||
| Tillage | 1 | ns | ns | |
| Genotype | 19 | ns | 2.02* | |
| Tillage x Genotype | 19 | ns | ns | |