Table 2.
Spike and grain measurements from dose–response experiments
| Treatment (no. of brushstrokes) | 0 | 1 | 3 | 6 | 9 | 12 | 15 | 20 | |
|---|---|---|---|---|---|---|---|---|---|
| Number of flowering spikes per plant | |||||||||
| n = 24 | 6.04 ± 0.332 | 7.29 ± 0.29 | 8.56 ± 0.34 | 7.53 ± 0.32 | 7.5 ± 0.27 | 7.00 ± 0.32 | 7.58 ± 0.25 | 7.54 ± 0.34 | |
| P = 0.018 | P < 0.001 | P = 0.012 | P = 0.012 | P = 0.116 | P = 0.002 | P = 0.003 | |||
| * | *** | * | * | ** | ** | ||||
| a | abc | c | bc | bc | ab | bc | bc | ||
| Average spike weight per plant (g) | |||||||||
| n = 6 | 1.79 ± 0.07 | 1.31 ± 0.07 | 1.29 ± 0.05 | 1.39 ± 0.04 | 1.23 ± 0.08 | 1.22 ± 0.11 | 1.22 ± 0.10 | 1.23 ± 0.04 | |
| P < 0.001 | P < 0.001 | P = 0.003 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | |||
| *** | *** | ** | *** | *** | *** | *** | |||
| a | b | b | b | b | b | b | b | ||
| Total spike weight (g) | |||||||||
| 11.25 ± 0.85 | 10.08 ± 0.23 | 11.28 ± 0.31 | 11.05 ± 0.64 | 9.87 ± 0.56 | 9.22 ± 0.96 | 10.44 ± 0.57 | 9.79 ± 0.85 | ||
| P = 0.693 | P = 1.000 | P = 1.000 | P = 0.540 | P = 0.172 | P = 0.920 | P = 0.476 | |||
| a | a | a | a | a | a | a | a | ||
| T3 Main tiller spike weight (g) | |||||||||
| 1.88 ± 0.10 | 1.41 ± 0.08 | 1.12 ± 0.16 | 1.45 ± 0.05 | 1.25 ± 0.10 | 0.97 ± 0.16 | 1.07 ± 0.14 | 0.98 ± 0.10 | ||
| P = 0.034 | P < 0.001 | P = 0.066 | P = 0.003 | P < 0.001 | P < 0.001 | P < 0.001 | |||
| * | *** | ** | *** | *** | *** | ||||
| a | ab | b | ab | b | b | b | b | ||
| Total grain volume (mm3) | |||||||||
| 898 ± 105.1 | 339 ± 77.3 | 318 ± 90.6 | 250 ± 51.1 | 305 ± 85.3 | 215 ± 35.4 | 147 ± 38.5 | 218 ± 61.6 | ||
| P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | |||
| *** | *** | *** | *** | *** | *** | *** | |||
| a | b | b | b | b | b | b | b | ||
| Grain count | |||||||||
| 33.6 ± 3.99 | 14.2 ± 2.91 | 12.7 ± 3.20 | 10.2 ± 1.85 | 12.8 ± 3.53 | 9.2 ± 1.40 | 7.5 ± 1.18 | 10.7 ± 2.29 | ||
| P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 | |||
| *** | *** | *** | *** | *** | *** | *** | |||
| a | b | b | b | b | b | b | b | ||
| Average grain volume (mm3) | |||||||||
| 26.8 ± 0.39 | 23.9 ± 1.10 | 25.0 ± 0.93 | 24.6 ± 1.28 | 23.7 ± 0.98 | 23.5 ± 1.59 | 19.6 ± 1.52 | 20.4 ± 1.15 | ||
| P = 0.122 | P = 0.750 | P = 0.609 | P = 0.090 | P = 0.146 | P < 0.001 | P < 0.001 | |||
| *** | *** | ||||||||
| a | abc | a | ab | abc | abc | c | bc | ||
| Grain length (mm) | |||||||||
| 4.97 ± 0.038 | 5.01 ± 0.113 | 5.08 ± 0.120 | 4.90 ± 0.142 | 5.05 ± 0.108 | 4.59 ± 0.161 | 5.00 ± 0.187 | 4.98 ± 0.139 | ||
| P = 1.000 | P = 0.935 | P = 0.998 | P = 0.991 | P = 0.038 | P = 1.000 | P = 1.000 | |||
| * | |||||||||
| ab | ab | b | ab | ab | a | ab | ab | ||
| Grain width (mm) | |||||||||
| 3.62 ± 0.041 | 3.36 ± 0.077 | 3.45 ± 0.079 | 3.50 ± 0.106 | 3.47 ± 0.104 | 3.49 ± 0.129 | 3.01 ± 0.122 | 3.12 ± 0.094 | ||
| P = 0.056 | P = 0.468 | P = 0.894 | P = 0.629 | P = 0.856 | P < 0.001 | P < 0.001 | |||
| *** | *** | ||||||||
| a | abc | ab | ab | ab | ab | c | bc | ||
| Grain depth (mm) | |||||||||
| 2.81 ± 0.025 | 2.66 ± 0.058 | 2.67 ± 0.055 | 2.67 ± 0.064 | 2.53 ± 0.059 | 2.68 ± 0.077 | 2.32 ± 0.089 | 2.30 ± 0.063 | ||
| P = 0.082 | P = 0.172 | P = 0.299 | P < 0.001 | P = 0.398 | P < 0.001 | P < 0.001 | |||
| *** | *** | *** | |||||||
| c | bc | bc | bc | ab | bc | a | a |
Significant differences to untreated controls are indicated by asterisks (*P < 0.05, **P < 0.01, ***P < 0.001).
ANOVA with a post-hoc Tukey test was performed to identify statistical differences (P < 0.05), indicated by lower case letters.
Data in this table are means ± standard error.