Trial at a Glance
- Season
- 2022/23
- Scale
- Full commercial trial rows
- Sites
- Four farms — Swears, Hayward, Price & Headlands
- Focus
- Nematicides · Fungicides · Soil programmes
The Trial
During the 2022/23 season Maguires ran commercial-scale trials on the farms of Mike Swears, Bob Hayward and Callum Price, and at Headlands. Each treatment ran on its own trial rows under normal commercial growing conditions. For every treatment we recorded root-knot nematode counts and gall ratings, average leaf weight, the percentage of leaf classified as good, the cost of the programme per hectare, and the expected yield per hectare.
Nematicides
Seven nematicide programmes were compared for root-knot nematode control. A count of 0 and a gall rating of 0 means clean roots at that site.
| Treatment | Nematode Count · Gall Rating (by site) | Avg Leaf Weight | Good Leaf | Cost / ha | Expected Yield |
|---|---|---|---|---|---|
| Vaniva | 0 · 0 (Swears) — 0 · 0 (Hayward) — 0 · 0 (Price) — 30 · 3 (Headlands) | 14.85 g | 83% | US$1,166.58 | 3,157 kg/ha |
| Velum | 0 · 0 (Swears) — 0 · 0 (Hayward) — 25 · 6 (Headlands) | 13.86 g | 81% | US$1,255.08 | 2,737 kg/ha |
| Velum + ½ Velum | 0 · 0 (Swears) | 13.65 g | 82% | US$1,421.76 | 2,846 kg/ha |
| Oxamyl Granules | 0 · 0 (Swears) — 0 · 0 (Hayward) | 13.91 g | 72% | US$1,041.58 | 2,667 kg/ha |
| Oxamyl Granules + Oxamyl Liquid | 0 · 0 (Swears) — 0 · 4 (Headlands) | 13.68 g | 60% | US$1,122.58 | 3,013 kg/ha |
| Vaniva + 2× Oxamyl | 0 · 2 (Price) | — | — | US$1,247.58 | — |
| EDB + 2× Oxamyl | 0 · 0 (Price) | — | — | US$1,299.58 | — |
Root Mass Comparison
Although several programmes kept galling at zero, the root systems told a different story. Plants lifted from each trial show a clear difference in root mass.
Vaniva
RecommendedTreated with Vaniva
A much larger root mass with dense hair roots — the biggest root system of all the nematicide trials.
Velum
Treated with Velum
Good nematode control, but a visibly smaller root system than the Vaniva-treated plants.
Recorded in the Field
Root samples were lifted, tagged and photographed with their field record cards more than 100 days after the last application.
Vaniva 450
114 days after last application
Location: Trelawney.
Farmer Nematicide Standard
110 days after last application
Variety KRK 66, transplanted 28-10-22. Location: Marondera.
Key Finding
Vaniva produced a much larger root mass — dense hair roots — and the heaviest leaf of the nematicide trials at 14.85 g, with 83% of its leaf classified as good.
Fungicides
Messenger ran on its own trial rows, while a programme of Bion, Azoxy Duo, Twist and Kasugamycin was used on all other trial rows. All the fungicides gave good control, and Kasugamycin — a bactericide — controlled Angular leaf spot. None of the trials were affected by disease.
| Treatment | Avg Leaf Weight | Good Leaf | Cost / ha | Expected Yield |
|---|---|---|---|---|
| Messenger | 14.22 g | 73% | US$1,291.08 | 3,017 kg/ha |
| Bion + Azoxy Duo + Twist + Kasugamycin | 13.93 g | 77% | US$1,255.08 | 2,737 kg/ha |
Soil & Nutrition Programmes
Five alternative soil and nutrition programmes were run alongside the standard, comparing leaf weight and quality against the cost of each programme.
| Programme | Avg Leaf Weight | Good Leaf | Cost / ha | Expected Yield |
|---|---|---|---|---|
| Carbon Capture | 15.08 g | 86% | US$1,341.88 | 3,201 kg/ha |
| ½ Standard + ½ Humagro | 13.64 g | 77% | US$1,388.88 | 2,887 kg/ha |
| Humagro | 13.95 g | 74% | US$1,693.58 | 3,031 kg/ha |
| Biological | 15.21 g | 74% | US$1,811.86 | 3,139 kg/ha |
| Biological + Humagro | 13.03 g | 59% | US$2,284.76 | 2,925 kg/ha |
Summary
Nematicides
Although there was no galling on some of the trials, there was a significant difference in root mass. Vaniva produced a much larger root system with dense hair roots — 14.85 g per leaf, with 83% of the leaf classified as good.
Fungicides
All the fungicides used gave good control, and Kasugamycin — a bactericide — controlled Angular leaf spot. None of the trials were affected by disease.
Carbon Capture
Turns atmospheric carbon into available carbon in the soil for the plant. The Carbon Capture rows averaged 15.08 g per leaf, with 86% of the leaf classified as good.
Key Finding
The Carbon Capture programme — turning atmospheric carbon into available soil carbon — delivered the best leaf quality of the season's trials: 15.08 g average leaf weight, 86% good leaf and an expected yield of 3,201 kg/ha.