Table 4.

Spike brittleness, spike harvest index (SpHI), threshing time and threshing efficiency in two groups of recombinant inbred lines showing extreme values of SpHI

Genotypic group	d.f.	Brittleness†	SpHI	Threshing time (s per 20 g spikes)	Threshing efficiency (g grain min−1)
Low SpHI		0·37	0·53b	42·2a	17·9b
High SpHI		0·38	0·67a	27·7b	34·2a
Source of variation
Genotypic group (F value)	1		617·5***	46·1***	81·8***
Genotype (group) (F value)	29		0·7n.s.	3·2***	1·8**
Block (F value)	2		3·1n.s.	25·3***	22·6***

^† Brittleness values did not distribute normally and hence were not analysed.

^a,b Different letters indicate significant differences between group means according to Tukey's HSD test at P < 0·05.

***, **, n.s. Significant F values at P < 0·001 or P < 0·01 or non-significant values, respectively.