Table 1. Trapezoidal integration of major (0.5–1 V) and minor (0.3–0.6 V) anodic CV, CDPV peaks; Eh in mV; and UV/visible absorbance at wavelengths attributable to trans-aconitic acid and polyphenol [8].
Only significantly different p-value (<0.05) are given for the cultivar and planting month effects with post-hoc Tukey’s HSD test. Total number of samples (n for 24 cultivars × planting months (April, May, and June of 2017) × triplicate field plots), mean, standard deviation (s.d.), minimum, maximum, and number of non-zero values for each variable. Cultivar×planting interaction was observed only for the UV/visible absorbance at 270 nm (p = 0.02).
| variable | n | mean | s.d. | min | max | non-zero | significant (<0.05) p value | |
|---|---|---|---|---|---|---|---|---|
| cultivar | plantinga | |||||||
| Trapezoidal integrated areas of anodic derivative current in juice | ||||||||
| CV (0.5-1V) | 172 | 2.1E-06 | 7.5E-07 | 7.8E-07 | 5.5E-06 | 172 | <0.00001 (No.5 Gambela>all others)* | <0.00001 (-↑) |
| CV (0.3–0.6V)b | 163 | 6.5E-08 | 3.4E-08 | 1.4E-08 | 2.0E-07 | 163 | 0.00001 (Chinese>No.5 Gambela, Atlas, N109AxAtals, Isidomba, N111AxAtlas, N110AxAtlas; | <0.00001 (-↓) |
| N110AxN98>No.5 Gambela, Atlas, Isidomba, N110AxAtlas; N98>Atlas; N111B>Atlas) | ||||||||
| CDPV (0.5-1V) | 172 | 2.7E-06 | 8.4E-07 | 7.3E-07 | 7.2E-06 | 172 | 0.00002 (No.5 Gambela>N98, N111AxDale, N111AxIsidomba, Isidomba, N110AxDale, N111AxN98, Dale, N109AxIsidomba, N109AxChinese, N110AxAtlas;* Atlas>Isidomba, N111AxN98, Dale; Isidomba<N109AxAtlas, Chinese, N109B; Dale<N109AxAtlas, N109B) | <0.00001 (↓↑) |
| CDPV (0.3–0.6V) | 171 | 2.1E-07 | 8.7E-08 | 3.5E-08 | 6.1E-07 | 171 | 0.00002 (N98>N110AxChinese, N111AxDale, Atlas, N109AxAtlas, Isidomba, N111AxN98, N109AxIsidomba, N110AxAtlas, N110AxIsidomba; N110AxN98>Isidomba, N111AxN98, N109AxIsidomba, N110AxAtlas; N111B>Isidomba) | <0.00001 (-↓) |
| bulk reduction potential and UV/visible absorbance of juice | ||||||||
| Eh (mV) | 173 | 281 | 32 | 98 | 373 | 173 | 0.02 (↓-) | |
| UV/vis 270nm (trans-aconitic acid) | 174 | 0.95 | 0.48 | 0.20 | 2.44 | 174 | <0.00001 (No.5 Gambela>all others;* Isidomba, Dale>Chinese, N111AxChinese, N111B; N109AxDale>Chinese, N111AxChinese, N111AxN98, N110B, N111B; Atlas>N111AxChinese) | <0.0001 (↑↑) |
| UV/vis 340nm (polyphenol) | 174 | 0.18 | 0.09 | 0.05 | 0.67 | 174 | <0.00001 (No.5 Gambela>all others)* | <0.00001 (↑-) |
aArrows indicate time trend (p<0.05 by post-hoc Tukey): increase (↑), decrease (↓), or no change (-) from April to May (first arrow), and from May to June (second arrow) planting dates; one arrow indicates significant difference only between April and June.
*Maximum in No.5 Gambela (p<0.05 by Tukey).
bIf peak exists.