Harvest / Post harvestPreliminary results on IAD Maturity classes for selected Stonefruit
| Fruit maturity » | Immature | Harvest ready | Mature | ||
|---|---|---|---|---|---|
| Maturity class » | Pre-climacteric | Onset climacteric | Climacteric | ||
| Ethylene production » | None | Low | Med. to high | ||
| Storage potential* » | Not recommended | Long | Short | ||
| Cultivar | Fruit type | Seasonality | IAD | IAD | IAD |
| Golden May | Apricot | Mid | > 1.20 | 1.19 - 0.60 | < 0.59 |
| Rose Bright | Nectarine | Early | > 1.00 | 1.00 - 0.40 | < 0.40 |
| Majestic Pearl | > 1.20 | 1.20 - 0.80 | < 0.80 | ||
| Summer Bright | Mid | > 0.70 | 0.69 - 0.30 | < 0.29 | |
| Fire Sweet | > 1.00 | 0.99 - 0.50 | < 0.49 | ||
| Summer Flare 26 | > 1.00 | 0.99 - 0.60 | < 0.59 | ||
| Summer Flare 34 | > 1.20 | 1.19 - 0.60 | < 0.59 | ||
| August Bright | Late | > 0.90 | 0.90 - 0.40 | < 0.40 | |
| August Fire | > 1.00 | 0.99 - 0.50 | < 0.49 | ||
| Autumn Bright | > 1.00 | 1.00 - 0.60 | < 0.60 | ||
| September Bright | > 1.20 | 1.20 - 0.50 | < 0.50 | ||
| September Red | > 1.10 | 1.09 - 0.60 | < 0.59 | ||
| O'Henry | Peach | Early | > 0.90 | 0.90 - 0.60 | < 0.60 |
| Snow Flame 23 | > 0.90 | 0.90 - 0.30 | < 0.30 | ||
| Ice Princess | Mid | > 1.30 | 1.30 - 0.50 | < 0.50 | |
| Red Haven | > 1.60 | 1.60 - 0.60 | < 0.60 | ||
| Snow Flame 25 | > 1.00 | 1.00 - 0.60 | < 0.60 | ||
| August Flame | Late | > 1.30 | 1.30 - 0.70 | < 0.70 | |
| O'Henry | > 1.20 | 1.20 - 0.70 | < 0.70 | ||
| September Sun | > 1.20 | 1.20 - 0.80 | < 0.80 | ||
| Angeleno | Plum | Late | > 1.30 | 1.29 - 1.00 | < 0.99 |
*Guide only
IAD and the DA meter
The DA meter measures the flesh greenness by reflectance at two wavelengths (670 and 720 nm) of light, near the chlorophyll-a absorbance peak. The reflectance is expressed as an index of absorption difference (IAD) scaled from 0 (fully ripe) to 3 (immature). Comparison of IAD with fruit ethylene production has shown a strong inverse relationship supporting the DA meter as a useful tool to measure fruit maturity.