Germination of conidiaz, formation of appressoriay and scab severity ratingx on apple leaves of Malus × domestica cultivar Golden Delicious.w
| Treatment | Concentration per litre (0.26 gal) | Germination (%) at Day 5 | Conidia with appressorium (%) at Day 5 | Leaf severity rating at Day 35 |
|---|---|---|---|---|
| Water (control) | - | 93±11.0ab | 90±8.0a | 5.0±0.60a |
| PhytoGard | 5.0 ml (0.17 fl oz) | 52±6.0def | 59±6.1cd | 2.6±0.23de |
| PhytoGard | 10 ml (0.33 fl oz) | 36±4.2fg | 44±4.7e | 2.0±0.20ef |
| Messenger | 3.2 g (0.14 oz) | 68±7.3bcde | 77±8.5abc | 3.2±0.36cd |
| Messenger | 6.4 g (0.28 oz) | 58±5.3de | 50±4.7de | 2.4±0.30def |
| Agri-Fos | 10 ml (0.33 fl oz) | 49±4.1ef | 70±8.0abc | 3.0±0.26cd |
| Agri-Fos | 20 ml (0.66 fl oz) | 44±3.8ef | 63±7.5bcd | 2.7±0.30cde |
| DSP | 3.0 ml (0.10 fl oz) | 46±5.0ef | 58±4.9cde | 2.3±0.30ef |
| DSP | 6.0 ml (0.20 fl oz) | 40±5.0fg | 63±5.5bcd | 2.2±0.38ef |
| Rigel | 3.0 ml (0.10 fl oz) | 60±6.1cde | 73±5.0abcd | 3.3±0.42bcd |
| Rigel | 6.0 ml (0.20 fl oz) | 55±5.9de | 60±6.1cd | 3.0±0.38 |
| Maxicrop Original | 10 ml (0.33 fl oz) | 90±12.0ab | 91±10.2a | 4.8±0.52ab |
| Maxicrop Original | 20 ml (0.66 fl oz) | 94±10.4ab | 92±9.7a | 5.0±0.55a |
| Resistim | 10 ml (0.33 fl oz) | 88±9.8a | 90±7.6a | 4.9±0.48a |
| Resistim | 20 ml (0.66 fl oz) | 92±13.1ab | 90±8.0a | 5.0±0.57a |
| Bioplex | 10 ml (0.33 fl oz) | 90±10.5ab | 93±9.8a | 5.0±0.63a |
| Bioplex | 20 ml (0.66 fl oz) | 86±8.8abc | 87±8.9a | 4.6±0.5.7ab |
| Fulcrum CRV | 10 ml (0.33 fl oz) | 96±13.4a | 93±10.7a | 5.0±0.60a |
| Fulcrum CRV | 20 ml (0.66 fl oz) | 94±12.1ab | 90±9.0a | 4.9±0.55a |
| Redicrop | 10 ml (0.33 fl oz) | 88±11.1ab | 86±9.9a | 5.0±0.61a |
| Redicrop | 20 ml (0.66 fl oz) | 92±12.5ab | 90±9.0a | 5.0±0.60a |
| Crop Set | 10 ml (0.33 fl oz) | 95±14.5a | 93±10.2a | 5.0±0.63a |
| Crop Set | 20 ml (0.66 fl oz) | 93±11.0ab | 90±8.7a | 5.0±0.62a |
| Superthrive | 0.25 ml (0.008 fl oz) | 80±8.9abc | 81±8.3ab | 4.4±0.44ab |
| Superthrive | 0.50 ml (0.16 fl oz) | 77±8.0abcd | 80±8.0abc | 4.0±0.39abc |
| Systhane | 0.3 ml (0.01 fl oz) | 27±2.6fg | 35±4.2e | 1.3±0.21ef |
| Systhane | 0.6 ml (0.02 fl oz) | 15±1.7g | 31±4.0e | 1.0±0.16f |
↵z As % of spores.
↵y As % of germinated spores.
↵x Detached leaf scab severity index: scale 0 = No scab observed; 1 = less than 5% of leaf area affected; 2 = 5%–20% of leaf area affected with some yellowing; 3 = 21%–50% of leaf area affected, significant leaf yellowing; 4 = 51%–80% of leaf area leaves affected, severe leaf yellowing; 5 = 81%–100% of leaf area with complete leaf yellowing.
↵w Data represents pooled mean of 2007 and 2008 studies except Rigel and Superthrive that were evaluated in 2008 only. Mean ± standard deviation of 80 leaves (germination of conidia, formation of appressoria) and 160 leaves scab severity rating. Lower case letters indicate significant differences between means for each evaluation date by Tukey highly significance test (P = 0.05). The lowest concentration used in Table 2 is based on manufacturer’s recommended rate (single strength). The other concentration tested represents a double strength product application.